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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Morales%2C+F&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Morales%2C+F&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Morales%2C+F&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.14258">arXiv:2406.14258</a> <span> [<a href="https://arxiv.org/pdf/2406.14258">pdf</a>, <a href="https://arxiv.org/format/2406.14258">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</span> </div> </div> <p class="title is-5 mathjax"> Ultrafast TACOS -- Terahertz-Assisted Chiro-Optical Spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Terentjevas%2C+J">Justas Terentjevas</a>, <a href="/search/physics?searchtype=author&query=Vindel-Zandbergen%2C+P">Patricia Vindel-Zandbergen</a>, <a href="/search/physics?searchtype=author&query=Rego%2C+L">Laura Rego</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Ord%C3%B3%C3%B1ez%2C+A">Andr茅s Ord贸帽ez</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=Ayuso%2C+D">David Ayuso</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.14258v1-abstract-short" style="display: inline;"> We bring together the advantages of terahertz (THz) and optical spectroscopies to introduce TACOS (Terahertz-Assisted Chiro-Optical Spectroscopy), a novel approach for ultrafast and highly efficient imaging of molecular chirality and control over chiral electronic dynamics. We show how, using a THz pulse, we can induce a transient electronic orientation in a medium of randomly oriented chiral mole… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.14258v1-abstract-full').style.display = 'inline'; document.getElementById('2406.14258v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.14258v1-abstract-full" style="display: none;"> We bring together the advantages of terahertz (THz) and optical spectroscopies to introduce TACOS (Terahertz-Assisted Chiro-Optical Spectroscopy), a novel approach for ultrafast and highly efficient imaging of molecular chirality and control over chiral electronic dynamics. We show how, using a THz pulse, we can induce a transient electronic orientation in a medium of randomly oriented chiral molecules that breaks the isotropy of the molecular sample. This symmetry breaking twists the nonlinear response of the medium to an ultrashort linearly polarised optical pulse in a highly enantiosensitive manner. As a result, the medium emits elliptically polarised light at new optical frequencies that records the molecular handedness via purely electric-dipole interactions. The long wavelength and period of the THz pulse enable both spatial coherence across the sample and a substantial degree of electronic orientation over the duration of the ultrashort optical pulse. TACOS does not require optical carrier-envelope phase stability or working in vacuum, and it creates exciting avenues for ultrafast and highly efficient chiral sensing and manipulation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.14258v1-abstract-full').style.display = 'none'; document.getElementById('2406.14258v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.04089">arXiv:2405.04089</a> <span> [<a href="https://arxiv.org/pdf/2405.04089">pdf</a>, <a href="https://arxiv.org/format/2405.04089">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> </div> <p class="title is-5 mathjax"> Bidirectional cascaded superfluorescent lasing in air enabled by resonant third harmonic photon exchange from nitrogen to argon </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nie%2C+Z">Zan Nie</a>, <a href="/search/physics?searchtype=author&query=Nambu%2C+N">Noa Nambu</a>, <a href="/search/physics?searchtype=author&query=Marsh%2C+K+A">Kenneth A. Marsh</a>, <a href="/search/physics?searchtype=author&query=Matteo%2C+D">Daniel Matteo</a>, <a href="/search/physics?searchtype=author&query=Patel%2C+C+K">C. Kumar Patel</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+C">Chaojie Zhang</a>, <a href="/search/physics?searchtype=author&query=Wu%2C+Y">Yipeng Wu</a>, <a href="/search/physics?searchtype=author&query=Carlstr%C3%B6m%2C+S">Stefanos Carlstr枚m</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Patchkovskii%2C+S">Serguei Patchkovskii</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a>, <a href="/search/physics?searchtype=author&query=Joshi%2C+C">Chan Joshi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.04089v1-abstract-short" style="display: inline;"> Cavity-free lasing in atmospheric air has stimulated intense research towards fundamental understanding of underlying physical mechanisms. In this Letter, we identify a new mechanism -- third harmonic photon mediated resonant energy transfer pathway leading to population inversion in argon via initial three-photon excitation of nitrogen molecules irradiated by intense 261 nm pulses -- that enables… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.04089v1-abstract-full').style.display = 'inline'; document.getElementById('2405.04089v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.04089v1-abstract-full" style="display: none;"> Cavity-free lasing in atmospheric air has stimulated intense research towards fundamental understanding of underlying physical mechanisms. In this Letter, we identify a new mechanism -- third harmonic photon mediated resonant energy transfer pathway leading to population inversion in argon via initial three-photon excitation of nitrogen molecules irradiated by intense 261 nm pulses -- that enables bidirectional two-color cascaded lasing in atmospheric air. By making pump-probe measurements, we conclusively show that such cascaded lasing results from superfluorescence (SF) rather than amplified spontaneous emission (ASE). Such cascaded lasing with the capability of producing bidirectional multicolor coherent pulses opens additional possibilities for remote sensing applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.04089v1-abstract-full').style.display = 'none'; document.getElementById('2405.04089v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.08742">arXiv:2404.08742</a> <span> [<a href="https://arxiv.org/pdf/2404.08742">pdf</a>, <a href="https://arxiv.org/format/2404.08742">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computational Physics">physics.comp-ph</span> </div> </div> <p class="title is-5 mathjax"> Photoionization-induced reflection for benchmarking of the photoionization models in solid </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Husakou%2C+A">Anton Husakou</a>, <a href="/search/physics?searchtype=author&query=Ruziev%2C+Z">Zukhriddin Ruziev</a>, <a href="/search/physics?searchtype=author&query=Koraboev%2C+K">Kamoliddin Koraboev</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Richter%2C+M">Maria Richter</a>, <a href="/search/physics?searchtype=author&query=Yabana%2C+K">Kazuhiro Yabana</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.08742v1-abstract-short" style="display: inline;"> The choice of the most suitable analytic photoionization model in solids is a challenging task with no default solution. Here we show how the best formalism can be determined based on the waveform of the pulse reflected by a sample due to photoionized almost-free electrons in the conduction band. For a typical case of diamond, we compare three simple models and benchmark them against highly accura… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.08742v1-abstract-full').style.display = 'inline'; document.getElementById('2404.08742v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.08742v1-abstract-full" style="display: none;"> The choice of the most suitable analytic photoionization model in solids is a challenging task with no default solution. Here we show how the best formalism can be determined based on the waveform of the pulse reflected by a sample due to photoionized almost-free electrons in the conduction band. For a typical case of diamond, we compare three simple models and benchmark them against highly accurate first-principle TDDFT simulation, by analysing the fit between the reflected pulses in time and frequency domain. For the aims of this paper, we have developed a software package, called PIGLET, for the FDTD simulation of photoionization-governed propagation, which is now freely available for the scientific community. Furthermore, we show that due to interband contributions for very short sub-10-fs pulses a semi-classical description based on any analytical photoionization model fail to provide an adequate description. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.08742v1-abstract-full').style.display = 'none'; document.getElementById('2404.08742v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 7 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.18470">arXiv:2402.18470</a> <span> [<a href="https://arxiv.org/pdf/2402.18470">pdf</a>, <a href="https://arxiv.org/format/2402.18470">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Data Analysis, Statistics and Probability">physics.data-an</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevX.14.031032">10.1103/PhysRevX.14.031032 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Higher-order null models as a lens for social systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Preti%2C+G">Giulia Preti</a>, <a href="/search/physics?searchtype=author&query=Fazzone%2C+A">Adriano Fazzone</a>, <a href="/search/physics?searchtype=author&query=Petri%2C+G">Giovanni Petri</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.18470v6-abstract-short" style="display: inline;"> Despite the widespread adoption of higher-order mathematical structures such as hypergraphs, methodological tools for their analysis lag behind those for traditional graphs. This work addresses a critical gap in this context by proposing two micro-canonical random null models for directed hypergraphs: the Directed Hypergraph Configuration Model (DHCM) and the Directed Hypergraph JOINT Model (DHJM)… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.18470v6-abstract-full').style.display = 'inline'; document.getElementById('2402.18470v6-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.18470v6-abstract-full" style="display: none;"> Despite the widespread adoption of higher-order mathematical structures such as hypergraphs, methodological tools for their analysis lag behind those for traditional graphs. This work addresses a critical gap in this context by proposing two micro-canonical random null models for directed hypergraphs: the Directed Hypergraph Configuration Model (DHCM) and the Directed Hypergraph JOINT Model (DHJM). These models preserve essential structural properties of directed hypergraphs such as node in- and out-degree sequences and hyperedge head and tail size sequences, or their joint tensor. We also describe two efficient MCMC algorithms, NuDHy-Degs and NuDHy-JOINT, to sample random hypergraphs from these ensembles. To showcase the interdisciplinary applicability of the proposed null models, we present three distinct use cases in sociology, epidemiology, and economics. First, we reveal the oscillatory behavior of increased homophily in opposition parties in the US Congress over a 40-year span, emphasizing the role of higher-order structures in quantifying political group homophily. Second, we investigate non-linear contagion in contact hyper-networks, demonstrating that disparities between simulations and theoretical predictions can be explained by considering higher-order joint degree distributions. Last, we examine the economic complexity of countries in the global trade network, showing that local network properties preserved by NuDHy explain the main structural economic complexity indexes. This work advances the development of null models for directed hypergraphs, addressing the intricate challenges posed by their complex entity relations, and providing a versatile suite of tools for researchers across various domains. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.18470v6-abstract-full').style.display = 'none'; document.getElementById('2402.18470v6-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in PRX</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.00213">arXiv:2402.00213</a> <span> [<a href="https://arxiv.org/pdf/2402.00213">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1039/c9nr04146j">10.1039/c9nr04146j <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Unravelling the polarity of InN quantum dots using a modified approach of negative-spherical-aberration imaging </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Rajak%2C+P">Piu Rajak</a>, <a href="/search/physics?searchtype=author&query=Islam%2C+M">Mahabul Islam</a>, <a href="/search/physics?searchtype=author&query=Jim%C3%A9nez%2C+J+J">J. J. Jim茅nez</a>, <a href="/search/physics?searchtype=author&query=M%C3%A1nuel%2C+J+M">J. M. M谩nuel</a>, <a href="/search/physics?searchtype=author&query=Aseev%2C+P">P. Aseev</a>, <a href="/search/physics?searchtype=author&query=Ga%C4%8Devi%C4%87%2C+%C5%BD">沤. Ga膷evi膰</a>, <a href="/search/physics?searchtype=author&query=Calleja%2C+E">E. Calleja</a>, <a href="/search/physics?searchtype=author&query=Garc%C3%ADa%2C+R">R. Garc铆a</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F+M">Francisco M. Morales</a>, <a href="/search/physics?searchtype=author&query=Bhattacharyya%2C+S">Somnath Bhattacharyya</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.00213v1-abstract-short" style="display: inline;"> InN quantum dots (QDs) are considered to be promising nanostructures for different device applications. For any hexagonal AB stacking semiconductor system, polarity is an important feature which affects the electronic properties. Therefore, the determination of this characteristic on any wurtzite (semi)polar III nitride compound or alloy is essential for defining its applicability. In this paper,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.00213v1-abstract-full').style.display = 'inline'; document.getElementById('2402.00213v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.00213v1-abstract-full" style="display: none;"> InN quantum dots (QDs) are considered to be promising nanostructures for different device applications. For any hexagonal AB stacking semiconductor system, polarity is an important feature which affects the electronic properties. Therefore, the determination of this characteristic on any wurtzite (semi)polar III nitride compound or alloy is essential for defining its applicability. In this paper, the polarity of InN QDs grown on silicon by indium droplet epitaxy plus nitridation and annealing was determined by a modified approach combining exit wave reconstruction with negative spherical aberration high resolution lattice imaging using TEM. Comparing the micrographs of two QDs from the same TEM specimen with the simulated images of InN slab structures generated under the same conditions as of the experiments, it was confirmed that the QDs of the present study are N polar. Given that the settlement of material's polarity has always been a tedious, indirect and controversial issue, the major value of our proposal is to provide a straightforward procedure to determine the polar direction from atomic-resolution focal series images. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.00213v1-abstract-full').style.display = 'none'; document.getElementById('2402.00213v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nanoscale, 2019, 11, 13632 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.13656">arXiv:2401.13656</a> <span> [<a href="https://arxiv.org/pdf/2401.13656">pdf</a>, <a href="https://arxiv.org/format/2401.13656">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computers and Society">cs.CY</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applications">stat.AP</span> </div> </div> <p class="title is-5 mathjax"> Navigating Multidimensional Ideologies with Reddit's Political Compass: Economic Conflict and Social Affinity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Colacrai%2C+E">Ernesto Colacrai</a>, <a href="/search/physics?searchtype=author&query=Cinus%2C+F">Federico Cinus</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Starnini%2C+M">Michele Starnini</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.13656v1-abstract-short" style="display: inline;"> The prevalent perspective in quantitative research on opinion dynamics flattens the landscape of the online political discourse into a traditional left--right dichotomy. While this approach helps simplify the analysis and modeling effort, it also neglects the intrinsic multidimensional richness of ideologies. In this study, we analyze social interactions on Reddit, under the lens of a multi-dimens… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.13656v1-abstract-full').style.display = 'inline'; document.getElementById('2401.13656v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.13656v1-abstract-full" style="display: none;"> The prevalent perspective in quantitative research on opinion dynamics flattens the landscape of the online political discourse into a traditional left--right dichotomy. While this approach helps simplify the analysis and modeling effort, it also neglects the intrinsic multidimensional richness of ideologies. In this study, we analyze social interactions on Reddit, under the lens of a multi-dimensional ideological framework: the political compass. We examine over 8 million comments posted on the subreddits /r/PoliticalCompass and /r/PoliticalCompassMemes during 2020--2022. By leveraging their self-declarations, we disentangle the ideological dimensions of users into economic (left--right) and social (libertarian--authoritarian) axes. In addition, we characterize users by their demographic attributes (age, gender, and affluence). We find significant homophily for interactions along the social axis of the political compass and demographic attributes. Compared to a null model, interactions among individuals of similar ideology surpass expectations by 6%. In contrast, we uncover a significant heterophily along the economic axis: left/right interactions exceed expectations by 10%. Furthermore, heterophilic interactions are characterized by a higher language toxicity than homophilic interactions, which hints at a conflictual discourse between every opposite ideology. Our results help reconcile apparent contradictions in recent literature, which found a superposition of homophilic and heterophilic interactions in online political discussions. By disentangling such interactions into the economic and social axes we pave the way for a deeper understanding of opinion dynamics on social media. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.13656v1-abstract-full').style.display = 'none'; document.getElementById('2401.13656v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.19951">arXiv:2310.19951</a> <span> [<a href="https://arxiv.org/pdf/2310.19951">pdf</a>, <a href="https://arxiv.org/format/2310.19951">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Computers and Society">cs.CY</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> </div> </div> <p class="title is-5 mathjax"> Measuring Behavior Change with Observational Studies: a Review </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pera%2C+A">Arianna Pera</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+d+F">Gianmarco de Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Aiello%2C+L+M">Luca Maria Aiello</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.19951v2-abstract-short" style="display: inline;"> Exploring behavioral change in the digital age is imperative for societal progress in the context of 21st-century challenges. We analyzed 148 articles (2000-2023) and built a map that categorizes behaviors and change detection methodologies, platforms of reference, and theoretical frameworks that characterize online behavior change. Our findings uncover a focus on sentiment shifts, an emphasis on… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.19951v2-abstract-full').style.display = 'inline'; document.getElementById('2310.19951v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.19951v2-abstract-full" style="display: none;"> Exploring behavioral change in the digital age is imperative for societal progress in the context of 21st-century challenges. We analyzed 148 articles (2000-2023) and built a map that categorizes behaviors and change detection methodologies, platforms of reference, and theoretical frameworks that characterize online behavior change. Our findings uncover a focus on sentiment shifts, an emphasis on API-restricted platforms, and limited theory integration. We call for methodologies able to capture a wider range of behavioral types, diverse data sources, and stronger theory-practice alignment in the study of online behavioral change. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.19951v2-abstract-full').style.display = 'none'; document.getElementById('2310.19951v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.18410">arXiv:2310.18410</a> <span> [<a href="https://arxiv.org/pdf/2310.18410">pdf</a>, <a href="https://arxiv.org/format/2310.18410">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</span> </div> </div> <p class="title is-5 mathjax"> Initial state preparation for quantum chemistry on quantum computers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Fomichev%2C+S">Stepan Fomichev</a>, <a href="/search/physics?searchtype=author&query=Hejazi%2C+K">Kasra Hejazi</a>, <a href="/search/physics?searchtype=author&query=Zini%2C+M+S">Modjtaba Shokrian Zini</a>, <a href="/search/physics?searchtype=author&query=Kiser%2C+M">Matthew Kiser</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+J+F">Joana Fraxanet Morales</a>, <a href="/search/physics?searchtype=author&query=Casares%2C+P+A+M">Pablo Antonio Moreno Casares</a>, <a href="/search/physics?searchtype=author&query=Delgado%2C+A">Alain Delgado</a>, <a href="/search/physics?searchtype=author&query=Huh%2C+J">Joonsuk Huh</a>, <a href="/search/physics?searchtype=author&query=Voigt%2C+A">Arne-Christian Voigt</a>, <a href="/search/physics?searchtype=author&query=Mueller%2C+J+E">Jonathan E. Mueller</a>, <a href="/search/physics?searchtype=author&query=Arrazola%2C+J+M">Juan Miguel Arrazola</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.18410v2-abstract-short" style="display: inline;"> Quantum algorithms for ground-state energy estimation of chemical systems require a high-quality initial state. However, initial state preparation is commonly either neglected entirely, or assumed to be solved by a simple product state like Hartree-Fock. Even if a nontrivial state is prepared, strong correlations render ground state overlap inadequate for quality assessment. In this work, we addre… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.18410v2-abstract-full').style.display = 'inline'; document.getElementById('2310.18410v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.18410v2-abstract-full" style="display: none;"> Quantum algorithms for ground-state energy estimation of chemical systems require a high-quality initial state. However, initial state preparation is commonly either neglected entirely, or assumed to be solved by a simple product state like Hartree-Fock. Even if a nontrivial state is prepared, strong correlations render ground state overlap inadequate for quality assessment. In this work, we address the initial state preparation problem with an end-to-end algorithm that prepares and quantifies the quality of initial states, accomplishing the latter with a new metric -- the energy distribution. To be able to prepare more complicated initial states, we introduce an implementation technique for states in the form of a sum of Slater determinants that exhibits significantly better scaling than all prior approaches. We also propose low-precision quantum phase estimation (QPE) for further state quality refinement. The complete algorithm is capable of generating high-quality states for energy estimation, and is shown in select cases to lower the overall estimation cost by several orders of magnitude when compared with the best single product state ansatz. More broadly, the energy distribution picture suggests that the goal of QPE should be reinterpreted as generating improvements compared to the energy of the initial state and other classical estimates, which can still be achieved even if QPE does not project directly onto the ground state. Finally, we show how the energy distribution can help in identifying potential quantum advantage. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.18410v2-abstract-full').style.display = 'none'; document.getElementById('2310.18410v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.10838">arXiv:2308.10838</a> <span> [<a href="https://arxiv.org/pdf/2308.10838">pdf</a>, <a href="https://arxiv.org/format/2308.10838">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevE.109.L053301">10.1103/PhysRevE.109.L053301 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An impossibility result for Markov Chain Monte Carlo sampling from micro-canonical bipartite graph ensembles </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Preti%2C+G">Giulia Preti</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Riondato%2C+M">Matteo Riondato</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.10838v3-abstract-short" style="display: inline;"> Markov Chain Monte Carlo (MCMC) algorithms are commonly used to sample from graph ensembles. Two graphs are neighbors in the state space if one can be obtained from the other with only a few modifications, e.g., edge rewirings. For many common ensembles, e.g., those preserving the degree sequences of bipartite graphs, rewiring operations involving two edges are sufficient to create a fully-connect… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.10838v3-abstract-full').style.display = 'inline'; document.getElementById('2308.10838v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.10838v3-abstract-full" style="display: none;"> Markov Chain Monte Carlo (MCMC) algorithms are commonly used to sample from graph ensembles. Two graphs are neighbors in the state space if one can be obtained from the other with only a few modifications, e.g., edge rewirings. For many common ensembles, e.g., those preserving the degree sequences of bipartite graphs, rewiring operations involving two edges are sufficient to create a fully-connected state space, and they can be performed efficiently. We show that, for ensembles of bipartite graphs with fixed degree sequences and number of butterflies (k2,2 bi-cliques), there is no universal constant c such that a rewiring of at most c edges at every step is sufficient for any such ensemble to be fully connected. Our proof relies on an explicit construction of a family of pairs of graphs with the same degree sequences and number of butterflies, with each pair indexed by a natural c, and such that any sequence of rewiring operations transforming one graph into the other must include at least one rewiring operation involving at least c edges. Whether rewiring these many edges is sufficient to guarantee the full connectivity of the state space of any such ensemble remains an open question. Our result implies the impossibility of developing efficient, graph-agnostic, MCMC algorithms for these ensembles, as the necessity to rewire an impractically large number of edges may hinder taking a step on the state space. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.10838v3-abstract-full').style.display = 'none'; document.getElementById('2308.10838v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Physical Review E</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.07598">arXiv:2302.07598</a> <span> [<a href="https://arxiv.org/pdf/2302.07598">pdf</a>, <a href="https://arxiv.org/format/2302.07598">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Computers and Society">cs.CY</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1145/3543507.3583468">10.1145/3543507.3583468 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Evidence of Demographic rather than Ideological Segregation in News Discussion on Reddit </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Monti%2C+C">Corrado Monti</a>, <a href="/search/physics?searchtype=author&query=D%27Ignazi%2C+J">Jacopo D'Ignazi</a>, <a href="/search/physics?searchtype=author&query=Starnini%2C+M">Michele Starnini</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2302.07598v2-abstract-short" style="display: inline;"> We evaluate homophily and heterophily among ideological and demographic groups in a typical opinion formation context: online discussions of current news. We analyze user interactions across five years in the r/news community on Reddit, one of the most visited websites in the United States. Then, we estimate demographic and ideological attributes of these users. Thanks to a comparison with a caref… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.07598v2-abstract-full').style.display = 'inline'; document.getElementById('2302.07598v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.07598v2-abstract-full" style="display: none;"> We evaluate homophily and heterophily among ideological and demographic groups in a typical opinion formation context: online discussions of current news. We analyze user interactions across five years in the r/news community on Reddit, one of the most visited websites in the United States. Then, we estimate demographic and ideological attributes of these users. Thanks to a comparison with a carefully-crafted network null model, we establish which pairs of attributes foster interactions and which ones inhibit them. Individuals prefer to engage with the opposite ideological side, which contradicts the echo chamber narrative. Instead, demographic groups are homophilic, as individuals tend to interact within their own group - even in an online setting where such attributes are not directly observable. In particular, we observe age and income segregation consistently across years: users tend to avoid interactions when belonging to different groups. These results persist after controlling for the degree of interest by each demographic group in different news topics. Our findings align with the theory that affective polarization - the difficulty in socializing across political boundaries-is more connected with an increasingly divided society, rather than ideological echo chambers on social media. We publicly release our anonymized data set and all the code to reproduce our results: https://github.com/corradomonti/demographic-homophily <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.07598v2-abstract-full').style.display = 'none'; document.getElementById('2302.07598v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Published at WWW '23</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">ACM Class:</span> J.4; K.4 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Proceedings of the ACM Web Conference 2023 (WWW '23), May 1-5, 2023, Austin, TX, USA. ACM </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.17234">arXiv:2210.17234</a> <span> [<a href="https://arxiv.org/pdf/2210.17234">pdf</a>, <a href="https://arxiv.org/format/2210.17234">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Computers and Society">cs.CY</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41598-022-21720-4">10.1038/s41598-022-21720-4 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The language of opinion change on social media under the lens of communicative action </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Monti%2C+C">Corrado Monti</a>, <a href="/search/physics?searchtype=author&query=Aiello%2C+L+M">Luca Maria Aiello</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Bonchi%2C+F">Francesco Bonchi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2210.17234v1-abstract-short" style="display: inline;"> Which messages are more effective at inducing a change of opinion in the listener? We approach this question within the frame of Habermas' theory of communicative action, which posits that the illocutionary intent of the message (its pragmatic meaning) is the key. Thanks to recent advances in natural language processing, we are able to operationalize this theory by extracting the latent social dim… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.17234v1-abstract-full').style.display = 'inline'; document.getElementById('2210.17234v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.17234v1-abstract-full" style="display: none;"> Which messages are more effective at inducing a change of opinion in the listener? We approach this question within the frame of Habermas' theory of communicative action, which posits that the illocutionary intent of the message (its pragmatic meaning) is the key. Thanks to recent advances in natural language processing, we are able to operationalize this theory by extracting the latent social dimensions of a message, namely archetypes of social intent of language, that come from social exchange theory. We identify key ingredients to opinion change by looking at more than 46k posts and more than 3.5M comments on Reddit's r/ChangeMyView, a debate forum where people try to change each other's opinion and explicitly mark opinion-changing comments with a special flag called "delta". Comments that express no intent are about 77% less likely to change the mind of the recipient, compared to comments that convey at least one social dimension. Among the various social dimensions, the ones that are most likely to produce an opinion change are knowledge, similarity, and trust, which resonates with Habermas' theory of communicative action. We also find other new important dimensions, such as appeals to power or empathetic expressions of support. Finally, in line with theories of constructive conflict, yet contrary to the popular characterization of conflict as the bane of modern social media, our findings show that voicing conflict in the context of a structured public debate can promote integration, especially when it is used to counter another conflictive stance. By leveraging recent advances in natural language processing, our work provides an empirical framework for Habermas' theory, finds concrete examples of its effects in the wild, and suggests its possible extension with a more faceted understanding of intent interpreted as social dimensions of language. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.17234v1-abstract-full').style.display = 'none'; document.getElementById('2210.17234v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Main paper: 13 pages, 1 figure, 3 tables. Supplementary material: 9 pages, 6 figures, 8 tables</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">ACM Class:</span> H.4.0; K.4.0 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Scientific Reports 12, 17920 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.09017">arXiv:2206.09017</a> <span> [<a href="https://arxiv.org/pdf/2206.09017">pdf</a>, <a href="https://arxiv.org/format/2206.09017">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Accelerator Physics">physics.acc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Highly spin-polarized multi-GeV electron beams generated by single-species plasma photocathodes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nie%2C+Z">Zan Nie</a>, <a href="/search/physics?searchtype=author&query=Li%2C+F">Fei Li</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Patchkovskii%2C+S">Serguei Patchkovskii</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=An%2C+W">Weiming An</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+C">Chaojie Zhang</a>, <a href="/search/physics?searchtype=author&query=Wu%2C+Y">Yipeng Wu</a>, <a href="/search/physics?searchtype=author&query=Nambu%2C+N">Noa Nambu</a>, <a href="/search/physics?searchtype=author&query=Matteo%2C+D">Daniel Matteo</a>, <a href="/search/physics?searchtype=author&query=Marsh%2C+K+A">Kenneth A. Marsh</a>, <a href="/search/physics?searchtype=author&query=Tsung%2C+F">Frank Tsung</a>, <a href="/search/physics?searchtype=author&query=Mori%2C+W+B">Warren B. Mori</a>, <a href="/search/physics?searchtype=author&query=Joshi%2C+C">Chan Joshi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2206.09017v1-abstract-short" style="display: inline;"> High-gradient and high-efficiency acceleration in plasma-based accelerators has been demonstrated, showing its potential as the building block for a future collider operating at the energy frontier of particle physics. However, generating and accelerating the required spin-polarized beams in such a collider using plasma-based accelerators has been a long-standing challenge. Here we show that the p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.09017v1-abstract-full').style.display = 'inline'; document.getElementById('2206.09017v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.09017v1-abstract-full" style="display: none;"> High-gradient and high-efficiency acceleration in plasma-based accelerators has been demonstrated, showing its potential as the building block for a future collider operating at the energy frontier of particle physics. However, generating and accelerating the required spin-polarized beams in such a collider using plasma-based accelerators has been a long-standing challenge. Here we show that the passage of a highly relativistic, high-current electron beam through a single-species (ytterbium) vapor excites a nonlinear plasma wake by primarily ionizing the two outer 6s electrons. Further photoionization of the resultant Yb2+ ions by a circularly polarized laser injects the 4f14 electrons into this wake generating a highly spin-polarized beam. Combining time-dependent Schrodinger equation simulations with particle-in-cell simulations, we show that a sub-femtosecond, high-current (4 kA) electron beam with up to 56% net spin polarization can be generated and accelerated to 15 GeV in just 41 cm. This relatively simple scheme solves the perplexing problem of producing spin-polarized relativistic electrons in plasma-based accelerators. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.09017v1-abstract-full').style.display = 'none'; document.getElementById('2206.09017v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">3 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2205.05052">arXiv:2205.05052</a> <span> [<a href="https://arxiv.org/pdf/2205.05052">pdf</a>, <a href="https://arxiv.org/format/2205.05052">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Econometrics">econ.EM</span> </div> </div> <p class="title is-5 mathjax"> On learning agent-based models from data </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Monti%2C+C">Corrado Monti</a>, <a href="/search/physics?searchtype=author&query=Pangallo%2C+M">Marco Pangallo</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Bonchi%2C+F">Francesco Bonchi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2205.05052v2-abstract-short" style="display: inline;"> Agent-Based Models (ABMs) are used in several fields to study the evolution of complex systems from micro-level assumptions. However, ABMs typically can not estimate agent-specific (or "micro") variables: this is a major limitation which prevents ABMs from harnessing micro-level data availability and which greatly limits their predictive power. In this paper, we propose a protocol to learn the lat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.05052v2-abstract-full').style.display = 'inline'; document.getElementById('2205.05052v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.05052v2-abstract-full" style="display: none;"> Agent-Based Models (ABMs) are used in several fields to study the evolution of complex systems from micro-level assumptions. However, ABMs typically can not estimate agent-specific (or "micro") variables: this is a major limitation which prevents ABMs from harnessing micro-level data availability and which greatly limits their predictive power. In this paper, we propose a protocol to learn the latent micro-variables of an ABM from data. The first step of our protocol is to reduce an ABM to a probabilistic model, characterized by a computationally tractable likelihood. This reduction follows two general design principles: balance of stochasticity and data availability, and replacement of unobservable discrete choices with differentiable approximations. Then, our protocol proceeds by maximizing the likelihood of the latent variables via a gradient-based expectation maximization algorithm. We demonstrate our protocol by applying it to an ABM of the housing market, in which agents with different incomes bid higher prices to live in high-income neighborhoods. We demonstrate that the obtained model allows accurate estimates of the latent variables, while preserving the general behavior of the ABM. We also show that our estimates can be used for out-of-sample forecasting. Our protocol can be seen as an alternative to black-box data assimilation methods, that forces the modeler to lay bare the assumptions of the model, to think about the inferential process, and to spot potential identification problems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.05052v2-abstract-full').style.display = 'none'; document.getElementById('2205.05052v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.17053">arXiv:2203.17053</a> <span> [<a href="https://arxiv.org/pdf/2203.17053">pdf</a>, <a href="https://arxiv.org/format/2203.17053">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1140/epjc/s10052-022-10791-2">10.1140/epjc/s10052-022-10791-2 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Separation of track- and shower-like energy deposits in ProtoDUNE-SP using a convolutional neural network </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=DUNE+Collaboration"> DUNE Collaboration</a>, <a href="/search/physics?searchtype=author&query=Abud%2C+A+A">A. Abed Abud</a>, <a href="/search/physics?searchtype=author&query=Abi%2C+B">B. Abi</a>, <a href="/search/physics?searchtype=author&query=Acciarri%2C+R">R. Acciarri</a>, <a href="/search/physics?searchtype=author&query=Acero%2C+M+A">M. A. Acero</a>, <a href="/search/physics?searchtype=author&query=Adames%2C+M+R">M. R. Adames</a>, <a href="/search/physics?searchtype=author&query=Adamov%2C+G">G. Adamov</a>, <a href="/search/physics?searchtype=author&query=Adamowski%2C+M">M. Adamowski</a>, <a href="/search/physics?searchtype=author&query=Adams%2C+D">D. Adams</a>, <a href="/search/physics?searchtype=author&query=Adinolfi%2C+M">M. Adinolfi</a>, <a href="/search/physics?searchtype=author&query=Aduszkiewicz%2C+A">A. Aduszkiewicz</a>, <a href="/search/physics?searchtype=author&query=Aguilar%2C+J">J. Aguilar</a>, <a href="/search/physics?searchtype=author&query=Ahmad%2C+Z">Z. Ahmad</a>, <a href="/search/physics?searchtype=author&query=Ahmed%2C+J">J. Ahmed</a>, <a href="/search/physics?searchtype=author&query=Aimard%2C+B">B. Aimard</a>, <a href="/search/physics?searchtype=author&query=Ali-Mohammadzadeh%2C+B">B. Ali-Mohammadzadeh</a>, <a href="/search/physics?searchtype=author&query=Alion%2C+T">T. Alion</a>, <a href="/search/physics?searchtype=author&query=Allison%2C+K">K. Allison</a>, <a href="/search/physics?searchtype=author&query=Monsalve%2C+S+A">S. Alonso Monsalve</a>, <a href="/search/physics?searchtype=author&query=AlRashed%2C+M">M. AlRashed</a>, <a href="/search/physics?searchtype=author&query=Alt%2C+C">C. Alt</a>, <a href="/search/physics?searchtype=author&query=Alton%2C+A">A. Alton</a>, <a href="/search/physics?searchtype=author&query=Alvarez%2C+R">R. Alvarez</a>, <a href="/search/physics?searchtype=author&query=Amedo%2C+P">P. Amedo</a>, <a href="/search/physics?searchtype=author&query=Anderson%2C+J">J. Anderson</a> , et al. (1204 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.17053v2-abstract-short" style="display: inline;"> Liquid argon time projection chamber detector technology provides high spatial and calorimetric resolutions on the charged particles traversing liquid argon. As a result, the technology has been used in a number of recent neutrino experiments, and is the technology of choice for the Deep Underground Neutrino Experiment (DUNE). In order to perform high precision measurements of neutrinos in the det… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.17053v2-abstract-full').style.display = 'inline'; document.getElementById('2203.17053v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.17053v2-abstract-full" style="display: none;"> Liquid argon time projection chamber detector technology provides high spatial and calorimetric resolutions on the charged particles traversing liquid argon. As a result, the technology has been used in a number of recent neutrino experiments, and is the technology of choice for the Deep Underground Neutrino Experiment (DUNE). In order to perform high precision measurements of neutrinos in the detector, final state particles need to be effectively identified, and their energy accurately reconstructed. This article proposes an algorithm based on a convolutional neural network to perform the classification of energy deposits and reconstructed particles as track-like or arising from electromagnetic cascades. Results from testing the algorithm on data from ProtoDUNE-SP, a prototype of the DUNE far detector, are presented. The network identifies track- and shower-like particles, as well as Michel electrons, with high efficiency. The performance of the algorithm is consistent between data and simulation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.17053v2-abstract-full').style.display = 'none'; document.getElementById('2203.17053v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 pages, 15 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> FERMILAB-PUB-22-240-AD-ESH-LBNF-ND-SCD, CERN-EP-2022-077 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Eur.Phys.J.C 82 (2022) 10, 903 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.16134">arXiv:2203.16134</a> <span> [<a href="https://arxiv.org/pdf/2203.16134">pdf</a>, <a href="https://arxiv.org/format/2203.16134">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> </div> <p class="title is-5 mathjax"> Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=DUNE+Collaboration"> DUNE Collaboration</a>, <a href="/search/physics?searchtype=author&query=Abud%2C+A+A">A. Abed Abud</a>, <a href="/search/physics?searchtype=author&query=Abi%2C+B">B. Abi</a>, <a href="/search/physics?searchtype=author&query=Acciarri%2C+R">R. Acciarri</a>, <a href="/search/physics?searchtype=author&query=Acero%2C+M+A">M. A. Acero</a>, <a href="/search/physics?searchtype=author&query=Adames%2C+M+R">M. R. Adames</a>, <a href="/search/physics?searchtype=author&query=Adamov%2C+G">G. Adamov</a>, <a href="/search/physics?searchtype=author&query=Adamowski%2C+M">M. Adamowski</a>, <a href="/search/physics?searchtype=author&query=Adams%2C+D">D. Adams</a>, <a href="/search/physics?searchtype=author&query=Adinolfi%2C+M">M. Adinolfi</a>, <a href="/search/physics?searchtype=author&query=Aduszkiewicz%2C+A">A. Aduszkiewicz</a>, <a href="/search/physics?searchtype=author&query=Aguilar%2C+J">J. Aguilar</a>, <a href="/search/physics?searchtype=author&query=Ahmad%2C+Z">Z. Ahmad</a>, <a href="/search/physics?searchtype=author&query=Ahmed%2C+J">J. Ahmed</a>, <a href="/search/physics?searchtype=author&query=Aimard%2C+B">B. Aimard</a>, <a href="/search/physics?searchtype=author&query=Ali-Mohammadzadeh%2C+B">B. Ali-Mohammadzadeh</a>, <a href="/search/physics?searchtype=author&query=Alion%2C+T">T. Alion</a>, <a href="/search/physics?searchtype=author&query=Allison%2C+K">K. Allison</a>, <a href="/search/physics?searchtype=author&query=Monsalve%2C+S+A">S. Alonso Monsalve</a>, <a href="/search/physics?searchtype=author&query=AlRashed%2C+M">M. AlRashed</a>, <a href="/search/physics?searchtype=author&query=Alt%2C+C">C. Alt</a>, <a href="/search/physics?searchtype=author&query=Alton%2C+A">A. Alton</a>, <a href="/search/physics?searchtype=author&query=Alvarez%2C+R">R. Alvarez</a>, <a href="/search/physics?searchtype=author&query=Amedo%2C+P">P. Amedo</a>, <a href="/search/physics?searchtype=author&query=Anderson%2C+J">J. Anderson</a> , et al. (1202 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.16134v4-abstract-short" style="display: inline;"> DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6x6x6m3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.16134v4-abstract-full').style.display = 'inline'; document.getElementById('2203.16134v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.16134v4-abstract-full" style="display: none;"> DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6x6x6m3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.16134v4-abstract-full').style.display = 'none'; document.getElementById('2203.16134v4-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 pages, 29 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> CERN-EP-DRAFT-MISC-2022-003; FERMILAB-PUB-22-242-LBNF </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.07622">arXiv:2203.07622</a> <span> [<a href="https://arxiv.org/pdf/2203.07622">pdf</a>, <a href="https://arxiv.org/format/2203.07622">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Accelerator Physics">physics.acc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> </div> </div> <p class="title is-5 mathjax"> The International Linear Collider: Report to Snowmass 2021 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Aryshev%2C+A">Alexander Aryshev</a>, <a href="/search/physics?searchtype=author&query=Behnke%2C+T">Ties Behnke</a>, <a href="/search/physics?searchtype=author&query=Berggren%2C+M">Mikael Berggren</a>, <a href="/search/physics?searchtype=author&query=Brau%2C+J">James Brau</a>, <a href="/search/physics?searchtype=author&query=Craig%2C+N">Nathaniel Craig</a>, <a href="/search/physics?searchtype=author&query=Freitas%2C+A">Ayres Freitas</a>, <a href="/search/physics?searchtype=author&query=Gaede%2C+F">Frank Gaede</a>, <a href="/search/physics?searchtype=author&query=Gessner%2C+S">Spencer Gessner</a>, <a href="/search/physics?searchtype=author&query=Gori%2C+S">Stefania Gori</a>, <a href="/search/physics?searchtype=author&query=Grojean%2C+C">Christophe Grojean</a>, <a href="/search/physics?searchtype=author&query=Heinemeyer%2C+S">Sven Heinemeyer</a>, <a href="/search/physics?searchtype=author&query=Jeans%2C+D">Daniel Jeans</a>, <a href="/search/physics?searchtype=author&query=Kruger%2C+K">Katja Kruger</a>, <a href="/search/physics?searchtype=author&query=List%2C+B">Benno List</a>, <a href="/search/physics?searchtype=author&query=List%2C+J">Jenny List</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+Z">Zhen Liu</a>, <a href="/search/physics?searchtype=author&query=Michizono%2C+S">Shinichiro Michizono</a>, <a href="/search/physics?searchtype=author&query=Miller%2C+D+W">David W. Miller</a>, <a href="/search/physics?searchtype=author&query=Moult%2C+I">Ian Moult</a>, <a href="/search/physics?searchtype=author&query=Murayama%2C+H">Hitoshi Murayama</a>, <a href="/search/physics?searchtype=author&query=Nakada%2C+T">Tatsuya Nakada</a>, <a href="/search/physics?searchtype=author&query=Nanni%2C+E">Emilio Nanni</a>, <a href="/search/physics?searchtype=author&query=Nojiri%2C+M">Mihoko Nojiri</a>, <a href="/search/physics?searchtype=author&query=Padamsee%2C+H">Hasan Padamsee</a>, <a href="/search/physics?searchtype=author&query=Perelstein%2C+M">Maxim Perelstein</a> , et al. (487 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.07622v3-abstract-short" style="display: inline;"> The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in the 2030s. The ILC addresses key questions for our current understanding of particle physics. It is based on a proven accelerator technology. Its experiments will challenge the Standard Model of particle physics and will provide a new window to look beyond it. This docu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.07622v3-abstract-full').style.display = 'inline'; document.getElementById('2203.07622v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.07622v3-abstract-full" style="display: none;"> The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in the 2030s. The ILC addresses key questions for our current understanding of particle physics. It is based on a proven accelerator technology. Its experiments will challenge the Standard Model of particle physics and will provide a new window to look beyond it. This document brings the story of the ILC up to date, emphasizing its strong physics motivation, its readiness for construction, and the opportunity it presents to the US and the global particle physics community. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.07622v3-abstract-full').style.display = 'none'; document.getElementById('2203.07622v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">356 pages, Large pdf file (40 MB) submitted to Snowmass 2021; v2 references to Snowmass contributions added, additional authors; v3 references added, some updates, additional authors</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> DESY-22-045, IFT--UAM/CSIC--22-028, KEK Preprint 2021-61, PNNL-SA-160884, SLAC-PUB-17662 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.04839">arXiv:2203.04839</a> <span> [<a href="https://arxiv.org/pdf/2203.04839">pdf</a>, <a href="https://arxiv.org/format/2203.04839">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.101.033405">10.1103/PhysRevA.101.033405 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Evidence of ac-Stark-shifted resonances in intense two-color circularly polarized laser fields </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Stammer%2C+P">Philipp Stammer</a>, <a href="/search/physics?searchtype=author&query=Patchkovskii%2C+S">Serguei Patchkovskii</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.04839v1-abstract-short" style="display: inline;"> We report on the appearance of a structure at low energies in the photo-electron momentum distribution of the hydrogen atom exposed to two-color counter-rotating bi-circular laser fields. These structures, which arise due to AC-Stark shifted resonances, break the three-fold symmetry, typical for the $蠅-2蠅$ bi-circular fields. We discuss the physical origin of this structure in terms of partial-wav… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.04839v1-abstract-full').style.display = 'inline'; document.getElementById('2203.04839v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.04839v1-abstract-full" style="display: none;"> We report on the appearance of a structure at low energies in the photo-electron momentum distribution of the hydrogen atom exposed to two-color counter-rotating bi-circular laser fields. These structures, which arise due to AC-Stark shifted resonances, break the three-fold symmetry, typical for the $蠅-2蠅$ bi-circular fields. We discuss the physical origin of this structure in terms of partial-wave interference between direct ionization channels and a resonant pathway, that passes through the AC-Stark shifted state and show how the underlying Rydberg state population depend on the field strength and pulse duration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.04839v1-abstract-full').style.display = 'none'; document.getElementById('2203.04839v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Physical Review A 101 (3), 033405 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.02658">arXiv:2112.02658</a> <span> [<a href="https://arxiv.org/pdf/2112.02658">pdf</a>, <a href="https://arxiv.org/format/2112.02658">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.129.243201">10.1103/PhysRevLett.129.243201 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Imprinting chirality on atoms using synthetic chiral light fields </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Mayer%2C+N">Nicola Mayer</a>, <a href="/search/physics?searchtype=author&query=Patchkovskii%2C+S">Serguei Patchkovskii</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2112.02658v3-abstract-short" style="display: inline;"> Atoms are usually thought of as achiral objects. However, one can construct superpositions of atomic states that are chiral [1]. Here we show how to excite such superpositions with tailored light fields both in the weak-field and strong-field regimes, using realistic laser parameters. First, we use time-dependent Schrodinger equation (TDSE) simulations to demonstrate the creation of a time-depende… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.02658v3-abstract-full').style.display = 'inline'; document.getElementById('2112.02658v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.02658v3-abstract-full" style="display: none;"> Atoms are usually thought of as achiral objects. However, one can construct superpositions of atomic states that are chiral [1]. Here we show how to excite such superpositions with tailored light fields both in the weak-field and strong-field regimes, using realistic laser parameters. First, we use time-dependent Schrodinger equation (TDSE) simulations to demonstrate the creation of a time-dependent bound chiral wavepacket in sodium atoms. Second, we show how the time-dependent handedness of this wavepacket can be probed by photoelectron circular dichroism, in spite of the central symmetry of the core potential. Third, we use TDSE simulations to show how chirality can be directly imprinted on a photoelectron wavepacket created by strong-field ionization and introduce an unambigous chiral measure that allows us to characterize its handedness. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.02658v3-abstract-full').style.display = 'none'; document.getElementById('2112.02658v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.01304">arXiv:2109.01304</a> <span> [<a href="https://arxiv.org/pdf/2109.01304">pdf</a>, <a href="https://arxiv.org/format/2109.01304">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> </div> <p class="title is-5 mathjax"> Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=DUNE+Collaboration"> DUNE Collaboration</a>, <a href="/search/physics?searchtype=author&query=Abud%2C+A+A">A. Abed Abud</a>, <a href="/search/physics?searchtype=author&query=Abi%2C+B">B. Abi</a>, <a href="/search/physics?searchtype=author&query=Acciarri%2C+R">R. Acciarri</a>, <a href="/search/physics?searchtype=author&query=Acero%2C+M+A">M. A. Acero</a>, <a href="/search/physics?searchtype=author&query=Adames%2C+M+R">M. R. Adames</a>, <a href="/search/physics?searchtype=author&query=Adamov%2C+G">G. Adamov</a>, <a href="/search/physics?searchtype=author&query=Adams%2C+D">D. Adams</a>, <a href="/search/physics?searchtype=author&query=Adinolfi%2C+M">M. Adinolfi</a>, <a href="/search/physics?searchtype=author&query=Aduszkiewicz%2C+A">A. Aduszkiewicz</a>, <a href="/search/physics?searchtype=author&query=Aguilar%2C+J">J. Aguilar</a>, <a href="/search/physics?searchtype=author&query=Ahmad%2C+Z">Z. Ahmad</a>, <a href="/search/physics?searchtype=author&query=Ahmed%2C+J">J. Ahmed</a>, <a href="/search/physics?searchtype=author&query=Aimard%2C+B">B. Aimard</a>, <a href="/search/physics?searchtype=author&query=Ali-Mohammadzadeh%2C+B">B. Ali-Mohammadzadeh</a>, <a href="/search/physics?searchtype=author&query=Alion%2C+T">T. Alion</a>, <a href="/search/physics?searchtype=author&query=Allison%2C+K">K. Allison</a>, <a href="/search/physics?searchtype=author&query=Monsalve%2C+S+A">S. Alonso Monsalve</a>, <a href="/search/physics?searchtype=author&query=AlRashed%2C+M">M. AlRashed</a>, <a href="/search/physics?searchtype=author&query=Alt%2C+C">C. Alt</a>, <a href="/search/physics?searchtype=author&query=Alton%2C+A">A. Alton</a>, <a href="/search/physics?searchtype=author&query=Amedo%2C+P">P. Amedo</a>, <a href="/search/physics?searchtype=author&query=Anderson%2C+J">J. Anderson</a>, <a href="/search/physics?searchtype=author&query=Andreopoulos%2C+C">C. Andreopoulos</a>, <a href="/search/physics?searchtype=author&query=Andreotti%2C+M">M. Andreotti</a> , et al. (1132 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.01304v1-abstract-short" style="display: inline;"> The Deep Underground Neutrino Experiment (DUNE) will produce world-leading neutrino oscillation measurements over the lifetime of the experiment. In this work, we explore DUNE's sensitivity to observe charge-parity violation (CPV) in the neutrino sector, and to resolve the mass ordering, for exposures of up to 100 kiloton-megawatt-years (kt-MW-yr). The analysis includes detailed uncertainties on t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.01304v1-abstract-full').style.display = 'inline'; document.getElementById('2109.01304v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.01304v1-abstract-full" style="display: none;"> The Deep Underground Neutrino Experiment (DUNE) will produce world-leading neutrino oscillation measurements over the lifetime of the experiment. In this work, we explore DUNE's sensitivity to observe charge-parity violation (CPV) in the neutrino sector, and to resolve the mass ordering, for exposures of up to 100 kiloton-megawatt-years (kt-MW-yr). The analysis includes detailed uncertainties on the flux prediction, the neutrino interaction model, and detector effects. We demonstrate that DUNE will be able to unambiguously resolve the neutrino mass ordering at a 3$蟽$ (5$蟽$) level, with a 66 (100) kt-MW-yr far detector exposure, and has the ability to make strong statements at significantly shorter exposures depending on the true value of other oscillation parameters. We also show that DUNE has the potential to make a robust measurement of CPV at a 3$蟽$ level with a 100 kt-MW-yr exposure for the maximally CP-violating values $未_{\rm CP}} = \pm蟺/2$. Additionally, the dependence of DUNE's sensitivity on the exposure taken in neutrino-enhanced and antineutrino-enhanced running is discussed. An equal fraction of exposure taken in each beam mode is found to be close to optimal when considered over the entire space of interest. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.01304v1-abstract-full').style.display = 'none'; document.getElementById('2109.01304v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> FERMILAB-PUB-21-391-ND </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.01103">arXiv:2109.01103</a> <span> [<a href="https://arxiv.org/pdf/2109.01103">pdf</a>, <a href="https://arxiv.org/format/2109.01103">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> </div> <p class="title is-5 mathjax"> Beam test performance of a highly granular silicon tungsten calorimeter technical prototype for the ILD </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Morales%2C+F+J">Fabricio Jimenez Morales</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.01103v1-abstract-short" style="display: inline;"> A highly granular silicon-tungsten electromagnetic calorimeter (SiW-ECAL) is the reference design of the ECAL for International Large Detector concept, one of the two detector concepts for the future International Linear Collider. Prototypes for this type of detector are developed within the CALICE Collaboration. The technological prototype addresses technical challenges such as integrated front-e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.01103v1-abstract-full').style.display = 'inline'; document.getElementById('2109.01103v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.01103v1-abstract-full" style="display: none;"> A highly granular silicon-tungsten electromagnetic calorimeter (SiW-ECAL) is the reference design of the ECAL for International Large Detector concept, one of the two detector concepts for the future International Linear Collider. Prototypes for this type of detector are developed within the CALICE Collaboration. The technological prototype addresses technical challenges such as integrated front-end electronics or compact layer and readout design. A stack of 7 layers was compiled and tested at DESY test beam facilities in 2017. We present preliminary results on the properties of the electromagnetic showers. An outline on the next steps is given. Finally, we illustrate the first steps of the digitization concept on simulations of the prototype. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.01103v1-abstract-full').style.display = 'none'; document.getElementById('2109.01103v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 3 figures. Talk presented at the International Conference on Technology and Instrumentation in Particle Physics (TIPP 2021), May 24-28 2021. Submitted to Journal of Physics: Conference Series</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.11668">arXiv:2108.11668</a> <span> [<a href="https://arxiv.org/pdf/2108.11668">pdf</a>, <a href="https://arxiv.org/format/2108.11668">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> </div> <p class="title is-5 mathjax"> Generation and characterisation of isolated attosecond pulses at 100kHz repetition rate </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Witting%2C+T">Tobias Witting</a>, <a href="/search/physics?searchtype=author&query=Osolodkov%2C+M">Mikhail Osolodkov</a>, <a href="/search/physics?searchtype=author&query=Schell%2C+F">Felix Schell</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Patchkovskii%2C+S">Serguei Patchkovskii</a>, <a href="/search/physics?searchtype=author&query=Susnjar%2C+P">Peter Susnjar</a>, <a href="/search/physics?searchtype=author&query=Cavalcante%2C+F">Fabio Cavalcante</a>, <a href="/search/physics?searchtype=author&query=Menoni%2C+C+S">Carmen S. Menoni</a>, <a href="/search/physics?searchtype=author&query=Schulz%2C+C+P">Claus P. Schulz</a>, <a href="/search/physics?searchtype=author&query=Furch%2C+F+J">Federico J. Furch</a>, <a href="/search/physics?searchtype=author&query=Vrakking%2C+M+J+J">Marc J. J. Vrakking</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2108.11668v1-abstract-short" style="display: inline;"> The generation of coherent light pulses in the extreme ultraviolet (XUV) spectral region with attosecond pulse durations constitutes the foundation of the field of attosecond science. Twenty years after the first demonstration of isolated attosecond pulses, they continue to be a unique tool enabling the observation and control of electron dynamics in atoms, molecules and solids. It has long been i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.11668v1-abstract-full').style.display = 'inline'; document.getElementById('2108.11668v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.11668v1-abstract-full" style="display: none;"> The generation of coherent light pulses in the extreme ultraviolet (XUV) spectral region with attosecond pulse durations constitutes the foundation of the field of attosecond science. Twenty years after the first demonstration of isolated attosecond pulses, they continue to be a unique tool enabling the observation and control of electron dynamics in atoms, molecules and solids. It has long been identified that an increase in the repetition rate of attosecond light sources is necessary for many applications in atomic and molecular physics, surface science, and imaging. Although high harmonic generation (HHG) at repetition rates exceeding 100 kHz, showing a continuum in the cut-off region of the XUV spectrum was already demonstrated in 2013, the number of photons per pulse was insufficient to perform pulse characterisation via attosecond streaking, let alone to perform a pump-probe experiment. Here we report on the generation and full characterisation of XUV attosecond pulses via HHG driven by near-single-cycle pulses at a repetition rate of 100 kHz. The high number of 10^6 XUV photons per pulse on target enables attosecond electron streaking experiments through which the XUV pulses are determined to consist of a dominant single attosecond pulse. These results open the door for attosecond pump-probe spectroscopy studies at a repetition rate one or two orders of magnitude above current implementations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.11668v1-abstract-full').style.display = 'none'; document.getElementById('2108.11668v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">27 Pages, 4 figures, supplementary information</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.01902">arXiv:2108.01902</a> <span> [<a href="https://arxiv.org/pdf/2108.01902">pdf</a>, <a href="https://arxiv.org/format/2108.01902">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> </div> </div> <p class="title is-5 mathjax"> Design, construction and operation of the ProtoDUNE-SP Liquid Argon TPC </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=DUNE+Collaboration"> DUNE Collaboration</a>, <a href="/search/physics?searchtype=author&query=Abud%2C+A+A">A. Abed Abud</a>, <a href="/search/physics?searchtype=author&query=Abi%2C+B">B. Abi</a>, <a href="/search/physics?searchtype=author&query=Acciarri%2C+R">R. Acciarri</a>, <a href="/search/physics?searchtype=author&query=Acero%2C+M+A">M. A. Acero</a>, <a href="/search/physics?searchtype=author&query=Adames%2C+M+R">M. R. Adames</a>, <a href="/search/physics?searchtype=author&query=Adamov%2C+G">G. Adamov</a>, <a href="/search/physics?searchtype=author&query=Adams%2C+D">D. Adams</a>, <a href="/search/physics?searchtype=author&query=Adinolfi%2C+M">M. Adinolfi</a>, <a href="/search/physics?searchtype=author&query=Aduszkiewicz%2C+A">A. Aduszkiewicz</a>, <a href="/search/physics?searchtype=author&query=Aguilar%2C+J">J. Aguilar</a>, <a href="/search/physics?searchtype=author&query=Ahmad%2C+Z">Z. Ahmad</a>, <a href="/search/physics?searchtype=author&query=Ahmed%2C+J">J. Ahmed</a>, <a href="/search/physics?searchtype=author&query=Ali-Mohammadzadeh%2C+B">B. Ali-Mohammadzadeh</a>, <a href="/search/physics?searchtype=author&query=Alion%2C+T">T. Alion</a>, <a href="/search/physics?searchtype=author&query=Allison%2C+K">K. Allison</a>, <a href="/search/physics?searchtype=author&query=Monsalve%2C+S+A">S. Alonso Monsalve</a>, <a href="/search/physics?searchtype=author&query=Alrashed%2C+M">M. Alrashed</a>, <a href="/search/physics?searchtype=author&query=Alt%2C+C">C. Alt</a>, <a href="/search/physics?searchtype=author&query=Alton%2C+A">A. Alton</a>, <a href="/search/physics?searchtype=author&query=Amedo%2C+P">P. Amedo</a>, <a href="/search/physics?searchtype=author&query=Anderson%2C+J">J. Anderson</a>, <a href="/search/physics?searchtype=author&query=Andreopoulos%2C+C">C. Andreopoulos</a>, <a href="/search/physics?searchtype=author&query=Andreotti%2C+M">M. Andreotti</a>, <a href="/search/physics?searchtype=author&query=Andrews%2C+M+P">M. P. Andrews</a> , et al. (1158 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2108.01902v3-abstract-short" style="display: inline;"> The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber (LArTPC) that was constructed and operated in the CERN North Area at the end of the H4 beamline. This detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment (DUNE), which will be constructed at the Sandford Underground Research Facility (SURF) in Lead, South Dakota, USA.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.01902v3-abstract-full').style.display = 'inline'; document.getElementById('2108.01902v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.01902v3-abstract-full" style="display: none;"> The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber (LArTPC) that was constructed and operated in the CERN North Area at the end of the H4 beamline. This detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment (DUNE), which will be constructed at the Sandford Underground Research Facility (SURF) in Lead, South Dakota, USA. The ProtoDUNE-SP detector incorporates full-size components as designed for DUNE and has an active volume of $7\times 6\times 7.2$~m$^3$. The H4 beam delivers incident particles with well-measured momenta and high-purity particle identification. ProtoDUNE-SP's successful operation between 2018 and 2020 demonstrates the effectiveness of the single-phase far detector design. This paper describes the design, construction, assembly and operation of the detector components. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.01902v3-abstract-full').style.display = 'none'; document.getElementById('2108.01902v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.07361">arXiv:2107.07361</a> <span> [<a href="https://arxiv.org/pdf/2107.07361">pdf</a>, <a href="https://arxiv.org/format/2107.07361">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computers and Society">cs.CY</span> </div> </div> <p class="title is-5 mathjax"> From Reddit to Wall Street: The role of committed minorities in financial collective action </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Lucchini%2C+L">Lorenzo Lucchini</a>, <a href="/search/physics?searchtype=author&query=Aiello%2C+L+M">Luca Maria Aiello</a>, <a href="/search/physics?searchtype=author&query=Alessandretti%2C+L">Laura Alessandretti</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Starnini%2C+M">Michele Starnini</a>, <a href="/search/physics?searchtype=author&query=Baronchelli%2C+A">Andrea Baronchelli</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2107.07361v2-abstract-short" style="display: inline;"> In January 2021, retail investors coordinated on Reddit to target short selling activity by hedge funds on GameStop shares, causing a surge in the share price and triggering significant losses for the funds involved. Such an effective collective action was unprecedented in finance, and its dynamics remain unclear. Here, we analyse Reddit and financial data and rationalise the events based on recen… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.07361v2-abstract-full').style.display = 'inline'; document.getElementById('2107.07361v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.07361v2-abstract-full" style="display: none;"> In January 2021, retail investors coordinated on Reddit to target short selling activity by hedge funds on GameStop shares, causing a surge in the share price and triggering significant losses for the funds involved. Such an effective collective action was unprecedented in finance, and its dynamics remain unclear. Here, we analyse Reddit and financial data and rationalise the events based on recent findings describing how a small fraction of committed individuals may trigger behavioural cascades. First, we operationalise the concept of individual commitment in financial discussions. Second, we show that the increase of commitment within Reddit predated the initial surge in price. Third, we reveal that initial committed users occupied a central position in the network of Reddit conversations. Finally, we show that the social identity of the broader Reddit community grew as the collective action unfolded. These findings shed light on financial collective action, as several observers anticipate it will grow in importance. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.07361v2-abstract-full').style.display = 'none'; document.getElementById('2107.07361v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Main: 9 pages, 3 figures, 3 tables. Supplementary: 7 pages, 7 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.07530">arXiv:2105.07530</a> <span> [<a href="https://arxiv.org/pdf/2105.07530">pdf</a>, <a href="https://arxiv.org/format/2105.07530">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Data Analysis, Statistics and Probability">physics.data-an</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.revip.2021.100063">10.1016/j.revip.2021.100063 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Advances in Multi-Variate Analysis Methods for New Physics Searches at the Large Hadron Collider </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Stakia%2C+A">Anna Stakia</a>, <a href="/search/physics?searchtype=author&query=Dorigo%2C+T">Tommaso Dorigo</a>, <a href="/search/physics?searchtype=author&query=Banelli%2C+G">Giovanni Banelli</a>, <a href="/search/physics?searchtype=author&query=Bortoletto%2C+D">Daniela Bortoletto</a>, <a href="/search/physics?searchtype=author&query=Casa%2C+A">Alessandro Casa</a>, <a href="/search/physics?searchtype=author&query=de+Castro%2C+P">Pablo de Castro</a>, <a href="/search/physics?searchtype=author&query=Delaere%2C+C">Christophe Delaere</a>, <a href="/search/physics?searchtype=author&query=Donini%2C+J">Julien Donini</a>, <a href="/search/physics?searchtype=author&query=Finos%2C+L">Livio Finos</a>, <a href="/search/physics?searchtype=author&query=Gallinaro%2C+M">Michele Gallinaro</a>, <a href="/search/physics?searchtype=author&query=Giammanco%2C+A">Andrea Giammanco</a>, <a href="/search/physics?searchtype=author&query=Held%2C+A">Alexander Held</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F+J">Fabricio Jim茅nez Morales</a>, <a href="/search/physics?searchtype=author&query=Kotkowski%2C+G">Grzegorz Kotkowski</a>, <a href="/search/physics?searchtype=author&query=Liew%2C+S+P">Seng Pei Liew</a>, <a href="/search/physics?searchtype=author&query=Maltoni%2C+F">Fabio Maltoni</a>, <a href="/search/physics?searchtype=author&query=Menardi%2C+G">Giovanna Menardi</a>, <a href="/search/physics?searchtype=author&query=Papavergou%2C+I">Ioanna Papavergou</a>, <a href="/search/physics?searchtype=author&query=Saggio%2C+A">Alessia Saggio</a>, <a href="/search/physics?searchtype=author&query=Scarpa%2C+B">Bruno Scarpa</a>, <a href="/search/physics?searchtype=author&query=Strong%2C+G+C">Giles C. Strong</a>, <a href="/search/physics?searchtype=author&query=Tosciri%2C+C">Cecilia Tosciri</a>, <a href="/search/physics?searchtype=author&query=Varela%2C+J">Jo茫o Varela</a>, <a href="/search/physics?searchtype=author&query=Vischia%2C+P">Pietro Vischia</a>, <a href="/search/physics?searchtype=author&query=Weiler%2C+A">Andreas Weiler</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.07530v2-abstract-short" style="display: inline;"> Between the years 2015 and 2019, members of the Horizon 2020-funded Innovative Training Network named "AMVA4NewPhysics" studied the customization and application of advanced multivariate analysis methods and statistical learning tools to high-energy physics problems, as well as developed entirely new ones. Many of those methods were successfully used to improve the sensitivity of data analyses per… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.07530v2-abstract-full').style.display = 'inline'; document.getElementById('2105.07530v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.07530v2-abstract-full" style="display: none;"> Between the years 2015 and 2019, members of the Horizon 2020-funded Innovative Training Network named "AMVA4NewPhysics" studied the customization and application of advanced multivariate analysis methods and statistical learning tools to high-energy physics problems, as well as developed entirely new ones. Many of those methods were successfully used to improve the sensitivity of data analyses performed by the ATLAS and CMS experiments at the CERN Large Hadron Collider; several others, still in the testing phase, promise to further improve the precision of measurements of fundamental physics parameters and the reach of searches for new phenomena. In this paper, the most relevant new tools, among those studied and developed, are presented along with the evaluation of their performances. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.07530v2-abstract-full').style.display = 'none'; document.getElementById('2105.07530v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">101 pages, 21 figures, submitted to Elsevier. [v2]: Updated to published version (in 'Reviews in Physics')</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Rev. Phys. 7 (2021) 100063 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2102.05477">arXiv:2102.05477</a> <span> [<a href="https://arxiv.org/pdf/2102.05477">pdf</a>, <a href="https://arxiv.org/format/2102.05477">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41598-021-81531-x">10.1038/s41598-021-81531-x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> No Echo in the Chambers of Political Interactions on Reddit </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Monti%2C+C">Corrado Monti</a>, <a href="/search/physics?searchtype=author&query=Starnini%2C+M">Michele Starnini</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2102.05477v1-abstract-short" style="display: inline;"> Echo chambers in online social networks, whereby users' beliefs are reinforced by interactions with like-minded peers and insulation from others' points of view, have been decried as a cause of political polarization. Here, we investigate their role in the debate around the 2016 US elections on Reddit, a fundamental platform for the success of Donald Trump. We identify Trump vs Clinton supporters… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.05477v1-abstract-full').style.display = 'inline'; document.getElementById('2102.05477v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2102.05477v1-abstract-full" style="display: none;"> Echo chambers in online social networks, whereby users' beliefs are reinforced by interactions with like-minded peers and insulation from others' points of view, have been decried as a cause of political polarization. Here, we investigate their role in the debate around the 2016 US elections on Reddit, a fundamental platform for the success of Donald Trump. We identify Trump vs Clinton supporters and reconstruct their political interaction network. We observe a preference for cross-cutting political interactions between the two communities rather than within-group interactions, thus contradicting the echo chamber narrative. Furthermore, these interactions are asymmetrical: Clinton supporters are particularly eager to answer comments by Trump supporters. Beside asymmetric heterophily, users show assortative behavior for activity, and disassortative, asymmetric behavior for popularity. Our findings are tested against a null model of random interactions, by using two different approaches: a network rewiring which preserves the activity of nodes, and a logit regression which takes into account possible confounding factors. Finally, we explore possible socio-demographic implications. Users show a tendency for geographical homophily and a small positive correlation between cross-interactions and voter abstention. Our findings shed light on public opinion formation on social media, calling for a better understanding of the social dynamics at play in this context. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.05477v1-abstract-full').style.display = 'none'; document.getElementById('2102.05477v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 February, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">ACM Class:</span> J.4; K.4 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Scientific Reports volume 11, Article number: 2818 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.10378">arXiv:2101.10378</a> <span> [<a href="https://arxiv.org/pdf/2101.10378">pdf</a>, <a href="https://arxiv.org/format/2101.10378">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Accelerator Physics">physics.acc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.126.054801;">10.1103/PhysRevLett.126.054801; <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.127.269901">10.1103/PhysRevLett.127.269901 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> In Situ Generation of High-Energy Spin-Polarized Electrons in a Beam-Driven Plasma Wakefield Accelerator </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nie%2C+Z">Zan Nie</a>, <a href="/search/physics?searchtype=author&query=Li%2C+F">Fei Li</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Patchkovskii%2C+S">Serguei Patchkovskii</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=An%2C+W">Weiming An</a>, <a href="/search/physics?searchtype=author&query=Nambu%2C+N">Noa Nambu</a>, <a href="/search/physics?searchtype=author&query=Matteo%2C+D">Daniel Matteo</a>, <a href="/search/physics?searchtype=author&query=Marsh%2C+K+A">Kenneth A. Marsh</a>, <a href="/search/physics?searchtype=author&query=Tsung%2C+F">Frank Tsung</a>, <a href="/search/physics?searchtype=author&query=Mori%2C+W+B">Warren B. Mori</a>, <a href="/search/physics?searchtype=author&query=Joshi%2C+C">Chan Joshi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.10378v2-abstract-short" style="display: inline;"> In situ generation of a high-energy, high-current, spin-polarized electron beam is an outstanding scientific challenge to the development of plasma-based accelerators for high-energy colliders. In this Letter we show how such a spin-polarized relativistic beam can be produced by ionization injection of electrons of certain atoms with a circularly polarized laser field into a beam-driven plasma wak… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.10378v2-abstract-full').style.display = 'inline'; document.getElementById('2101.10378v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.10378v2-abstract-full" style="display: none;"> In situ generation of a high-energy, high-current, spin-polarized electron beam is an outstanding scientific challenge to the development of plasma-based accelerators for high-energy colliders. In this Letter we show how such a spin-polarized relativistic beam can be produced by ionization injection of electrons of certain atoms with a circularly polarized laser field into a beam-driven plasma wakefield accelerator, providing a much desired one-step solution to this challenge. Using time-dependent Schr枚dinger equation (TDSE) simulations, we show the propensity rule of spin-dependent ionization of xenon atoms can be reversed in the strong-field multi-photon regime compared with the non-adiabatic tunneling regime, leading to high total spin-polarization. Furthermore, three-dimensional particle-in-cell (PIC) simulations are incorporated with TDSE simulations, providing start-to-end simulations of spin-dependent strong-field ionization of xenon atoms and subsequent trapping, acceleration, and preservation of electron spin-polarization in lithium plasma. We show the generation of a high-current (0.8 kA), ultra-low-normalized-emittance (~37 nm), and high-energy (2.7 GeV) electron beam within just 11 cm distance, with up to ~31% net spin polarization. Higher current, energy, and net spin-polarization beams are possible by optimizing this concept, thus solving a long-standing problem facing the development of plasma accelerators. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.10378v2-abstract-full').style.display = 'none'; document.getElementById('2101.10378v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2004.09603">arXiv:2004.09603</a> <span> [<a href="https://arxiv.org/pdf/2004.09603">pdf</a>, <a href="https://arxiv.org/format/2004.09603">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computers and Society">cs.CY</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> </div> </div> <p class="title is-5 mathjax"> Echo Chambers on Social Media: A comparative analysis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Cinelli%2C+M">Matteo Cinelli</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Galeazzi%2C+A">Alessandro Galeazzi</a>, <a href="/search/physics?searchtype=author&query=Quattrociocchi%2C+W">Walter Quattrociocchi</a>, <a href="/search/physics?searchtype=author&query=Starnini%2C+M">Michele Starnini</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2004.09603v1-abstract-short" style="display: inline;"> Recent studies have shown that online users tend to select information adhering to their system of beliefs, ignore information that does not, and join groups - i.e., echo chambers - around a shared narrative. Although a quantitative methodology for their identification is still missing, the phenomenon of echo chambers is widely debated both at scientific and political level. To shed light on this… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.09603v1-abstract-full').style.display = 'inline'; document.getElementById('2004.09603v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.09603v1-abstract-full" style="display: none;"> Recent studies have shown that online users tend to select information adhering to their system of beliefs, ignore information that does not, and join groups - i.e., echo chambers - around a shared narrative. Although a quantitative methodology for their identification is still missing, the phenomenon of echo chambers is widely debated both at scientific and political level. To shed light on this issue, we introduce an operational definition of echo chambers and perform a massive comparative analysis on more than 1B pieces of contents produced by 1M users on four social media platforms: Facebook, Twitter, Reddit, and Gab. We infer the leaning of users about controversial topics - ranging from vaccines to abortion - and reconstruct their interaction networks by analyzing different features, such as shared links domain, followed pages, follower relationship and commented posts. Our method quantifies the existence of echo-chambers along two main dimensions: homophily in the interaction networks and bias in the information diffusion toward likely-minded peers. We find peculiar differences across social media. Indeed, while Facebook and Twitter present clear-cut echo chambers in all the observed dataset, Reddit and Gab do not. Finally, we test the role of the social media platform on news consumption by comparing Reddit and Facebook. Again, we find support for the hypothesis that platforms implementing news feed algorithms like Facebook may elicit the emergence of echo-chambers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.09603v1-abstract-full').style.display = 'none'; document.getElementById('2004.09603v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2004.04067">arXiv:2004.04067</a> <span> [<a href="https://arxiv.org/pdf/2004.04067">pdf</a>, <a href="https://arxiv.org/ps/2004.04067">ps</a>, <a href="https://arxiv.org/format/2004.04067">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.102.013111">10.1103/PhysRevA.102.013111 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> N$_2^+$ Lasing: Gain and Absorption in the Presence of Rotational Coherence </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Lytova%2C+M">Marianna Lytova</a>, <a href="/search/physics?searchtype=author&query=Richter%2C+M">Maria Richter</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a>, <a href="/search/physics?searchtype=author&query=Spanner%2C+M">Michael Spanner</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2004.04067v1-abstract-short" style="display: inline;"> We simulate the pump-probe experiments of lasing in molecular nitrogen ions with particular interest on the effects of rotational wave-packet dynamics. Our computations demonstrate that the coherent preparation of rotational wave packets in N$_2^+$ by an intense short non-resonant pulse results in a modulation of the subsequent emission from $B^2危_u^+ \rightarrow X^2危_g^+$ transitions induced by a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.04067v1-abstract-full').style.display = 'inline'; document.getElementById('2004.04067v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.04067v1-abstract-full" style="display: none;"> We simulate the pump-probe experiments of lasing in molecular nitrogen ions with particular interest on the effects of rotational wave-packet dynamics. Our computations demonstrate that the coherent preparation of rotational wave packets in N$_2^+$ by an intense short non-resonant pulse results in a modulation of the subsequent emission from $B^2危_u^+ \rightarrow X^2危_g^+$ transitions induced by a resonant seed pulse. We model the dynamics of such pumping and emission using density matrix theory to describe the N$_2^+$ dynamics and the Maxwell wave equation to model the seed pulse propagation. We show that the gain and absorption of a delayed seed pulse is dependent on the pump-seed delay, that is, the rotational coherences excited by the pump pulse can modulate the gain and absorption of the delayed seed pulse. Further, we demonstrate that the coherent rotational dynamics of the nitrogen ions can cause lasing without electronic inversion. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.04067v1-abstract-full').style.display = 'none'; document.getElementById('2004.04067v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A 102, 013111 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.08081">arXiv:2001.08081</a> <span> [<a href="https://arxiv.org/pdf/2001.08081">pdf</a>, <a href="https://arxiv.org/format/2001.08081">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OPTICA.390665">10.1364/OPTICA.390665 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Rotational Quantum Beat Lasing Without Inversion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Richter%2C+M">Maria Richter</a>, <a href="/search/physics?searchtype=author&query=Lytova%2C+M">Marianna Lytova</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Haessler%2C+S">Stefan Haessler</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=Spanner%2C+M">Michael Spanner</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2001.08081v1-abstract-short" style="display: inline;"> In standard lasers, light amplification requires population inversion between an upper and a lower state to break the reciprocity between absorption and stimulated emission. However, in a medium prepared in a specific superposition state, quantum interference may fully suppress absorption while leaving stimulated emission intact, opening the possibility of lasing without inversion. Here we show th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.08081v1-abstract-full').style.display = 'inline'; document.getElementById('2001.08081v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.08081v1-abstract-full" style="display: none;"> In standard lasers, light amplification requires population inversion between an upper and a lower state to break the reciprocity between absorption and stimulated emission. However, in a medium prepared in a specific superposition state, quantum interference may fully suppress absorption while leaving stimulated emission intact, opening the possibility of lasing without inversion. Here we show that lasing without inversion arises naturally during propagation of intense femtosecond laser pulses in air. It is triggered by the combination of molecular ionization and molecular alignment, both unavoidable in intense light fields. The effect could enable inversionless amplification of broadband radiation in many molecular gases, opening unusual opportunities for remote sensing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.08081v1-abstract-full').style.display = 'none'; document.getElementById('2001.08081v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Optica 7(6) (2020) 586-592 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1912.08955">arXiv:1912.08955</a> <span> [<a href="https://arxiv.org/pdf/1912.08955">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.apsusc.2020.146312">10.1016/j.apsusc.2020.146312 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Optical and nanostructural insights of oblique angle deposited layers applied for photononic coatings </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Maudet%2C+F">Florian Maudet</a>, <a href="/search/physics?searchtype=author&query=Lacroix%2C+B">Bertrand Lacroix</a>, <a href="/search/physics?searchtype=author&query=Santos%2C+A+J">Antonio J. Santos</a>, <a href="/search/physics?searchtype=author&query=Paumier%2C+F">Fabien Paumier</a>, <a href="/search/physics?searchtype=author&query=Paraillous%2C+M">Maxime Paraillous</a>, <a href="/search/physics?searchtype=author&query=Hurand%2C+S">Simon Hurand</a>, <a href="/search/physics?searchtype=author&query=Corvisier%2C+A">Alan Corvisier</a>, <a href="/search/physics?searchtype=author&query=Marsal%2C+C">Cecile Marsal</a>, <a href="/search/physics?searchtype=author&query=Giroire%2C+B">Baptiste Giroire</a>, <a href="/search/physics?searchtype=author&query=Dupeyrat%2C+C">Cyril Dupeyrat</a>, <a href="/search/physics?searchtype=author&query=Garc%C3%ADa%2C+R">Rafael Garc铆a</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F+M">Francisco M. Morales</a>, <a href="/search/physics?searchtype=author&query=Girardeau%2C+T">Thierry Girardeau</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1912.08955v1-abstract-short" style="display: inline;"> Oblique angle deposition (OAD) is a nanostructuration method widely used to tune the optical properties of thin films. The introduction of porosity controlled by the deposition angle is used to develop the architecture of each layer and stack that enable modifying and optimizing the optical properties of the constituent layers for optimal design. However, optical properties of these nanostructured… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.08955v1-abstract-full').style.display = 'inline'; document.getElementById('1912.08955v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1912.08955v1-abstract-full" style="display: none;"> Oblique angle deposition (OAD) is a nanostructuration method widely used to tune the optical properties of thin films. The introduction of porosity controlled by the deposition angle is used to develop the architecture of each layer and stack that enable modifying and optimizing the optical properties of the constituent layers for optimal design. However, optical properties of these nanostructured layers may differ greatly from those of dense layers due to the presence of anisotropy, refractive index gradient and scattering. This work focuses on OAD layers based on a reference photonic material such as SiO2 and it aims at taking into account all these effects in the description of the optical response. For that, the nanostructure has been analyzed with a complete SEM study and key parameters like the porosity gradient profile and aspect ratio of the nanocolumns were extracted. The samples were then characterized by generalized ellipsometry to evaluate the influence of morphological anisotropy and porosity gradient on the optical response of the films. Based on this microstructural study, an original optical model is presented to fit the features of new optical properties. A reliable correspondence is observed between the optical model parameters and the microstructure characteristics like the column angle and the porosity gradient. This demonstrates that such complex microstructural parameters can be easily accessed solely from optical measurements. All the work has enabled us to develop a two-layer anti-reflective coating that already demonstrate high level of transmission. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.08955v1-abstract-full').style.display = 'none'; document.getElementById('1912.08955v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 December, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1906.06299">arXiv:1906.06299</a> <span> [<a href="https://arxiv.org/pdf/1906.06299">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.actamat.2020.02.014">10.1016/j.actamat.2020.02.014 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the importance of light scattering for high performances nanostructured antireflective surfaces </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Maudet%2C+F">Florian Maudet</a>, <a href="/search/physics?searchtype=author&query=Lacroix%2C+B">Bertrand Lacroix</a>, <a href="/search/physics?searchtype=author&query=Santos%2C+A+J">Antonio J. Santos</a>, <a href="/search/physics?searchtype=author&query=Paumier%2C+F">Fabien Paumier</a>, <a href="/search/physics?searchtype=author&query=Paraillous%2C+M">Maxime Paraillous</a>, <a href="/search/physics?searchtype=author&query=Hurand%2C+S">Simon Hurand</a>, <a href="/search/physics?searchtype=author&query=Corvisier%2C+A">Alan Corvisier</a>, <a href="/search/physics?searchtype=author&query=Dupeyrat%2C+C">Cyril Dupeyrat</a>, <a href="/search/physics?searchtype=author&query=Garc%C3%ADa%2C+R">Rafael Garc铆a</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F+M">Francisco M. Morales</a>, <a href="/search/physics?searchtype=author&query=Girardeau%2C+T">Thierry Girardeau</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1906.06299v1-abstract-short" style="display: inline;"> An antireflective coating presenting a continuous refractive index gradient is theoretically better than its discrete counterpart because it can give rise to a perfect broadband transparency. This kind of surface treatment can be obtained with nanostructures like moth-eye. Despite the light scattering behavior must be accounted as it can lead to a significant transmittance drop, no methods are act… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.06299v1-abstract-full').style.display = 'inline'; document.getElementById('1906.06299v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1906.06299v1-abstract-full" style="display: none;"> An antireflective coating presenting a continuous refractive index gradient is theoretically better than its discrete counterpart because it can give rise to a perfect broadband transparency. This kind of surface treatment can be obtained with nanostructures like moth-eye. Despite the light scattering behavior must be accounted as it can lead to a significant transmittance drop, no methods are actually available to anticipate scattering losses in such nanostructured antireflective coatings. To overcome this current limitation, we present here an original way to simulate the scattering losses in these systems and routes to optimize the transparency. This method, which was validated by a comparative study of coatings presenting refractive indices with either discrete or continuous gradient, shows that a discrete antireflective coating bilayer made by oblique angle deposition allows reaching ultra-high mean transmittance of 98.97% over the broadband [400-1800] nm. Such simple surface treatment outperforms moth-eye architectures thanks to both interference effect and small dimensions nanostructures that minimize the scattering losses as confirmed by finite-difference time domain simulations performed on reconstructed volumes obtained from electron tomography experiments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.06299v1-abstract-full').style.display = 'none'; document.getElementById('1906.06299v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 June, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1810.10856">arXiv:1810.10856</a> <span> [<a href="https://arxiv.org/pdf/1810.10856">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41567-018-0105-0">10.1038/s41567-018-0105-0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Amplification of intense light fields by nearly free electrons </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Matthews%2C+M">Mary Matthews</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Patas%2C+A">Alexander Patas</a>, <a href="/search/physics?searchtype=author&query=Lindinger%2C+A">Albrecht Lindinger</a>, <a href="/search/physics?searchtype=author&query=Gateau%2C+J">Julien Gateau</a>, <a href="/search/physics?searchtype=author&query=Berti%2C+N">Nicolas Berti</a>, <a href="/search/physics?searchtype=author&query=Hermelin%2C+S">Sylvain Hermelin</a>, <a href="/search/physics?searchtype=author&query=Kasparian%2C+J">J茅r么me Kasparian</a>, <a href="/search/physics?searchtype=author&query=Richter%2C+M">Maria Richter</a>, <a href="/search/physics?searchtype=author&query=Bredtmann%2C+T">Timm Bredtmann</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=Wolf%2C+J">Jean-Pierre Wolf</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1810.10856v1-abstract-short" style="display: inline;"> Light can be used to modify and control properties of media, as in the case of electromagnetically induced transparency or, more recently, for the generation of slow light or bright coherent XUV and X-ray radiation. Particularly unusual states of matter can be created by light fields with strengths comparable to the Coulomb field that binds valence electrons in atoms, leading to nearly-free electr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.10856v1-abstract-full').style.display = 'inline'; document.getElementById('1810.10856v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1810.10856v1-abstract-full" style="display: none;"> Light can be used to modify and control properties of media, as in the case of electromagnetically induced transparency or, more recently, for the generation of slow light or bright coherent XUV and X-ray radiation. Particularly unusual states of matter can be created by light fields with strengths comparable to the Coulomb field that binds valence electrons in atoms, leading to nearly-free electrons oscillating in the laser field and yet still loosely bound to the core [1,2]. These are known as Kramers-Henneberger states [3], a specific example of laser-dressed states [2]. Here, we demonstrate that these states arise not only in isolated atoms [4,5], but also in rare gases, at and above atmospheric pressure, where they can act as a gain medium during laser filamentation. Using shaped laser pulses, gain in these states is achieved within just a few cycles of the guided field. The corresponding lasing emission is a signature of population inversion in these states and of their stability against ionization. Our work demonstrates that these unusual states of neutral atoms can be exploited to create a general ultrafast gain mechanism during laser filamentation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.10856v1-abstract-full').style.display = 'none'; document.getElementById('1810.10856v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 October, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 4 figures, 10 pages supplementary material, 8 supplementary figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Physics 14, 695 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1805.02250">arXiv:1805.02250</a> <span> [<a href="https://arxiv.org/pdf/1805.02250">pdf</a>, <a href="https://arxiv.org/format/1805.02250">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.97.023409">10.1103/PhysRevA.97.023409 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Control of attosecond light polarization in two-color bi-circular fields </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Jim%C3%A9nez-Gal%C3%A1n%2C+%C3%81">脕lvaro Jim茅nez-Gal谩n</a>, <a href="/search/physics?searchtype=author&query=Zhavoronkov%2C+N">Nick Zhavoronkov</a>, <a href="/search/physics?searchtype=author&query=Ayuso%2C+D">David Ayuso</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Patchkovskii%2C+S">Serguei Patchkovskii</a>, <a href="/search/physics?searchtype=author&query=Schloz%2C+M">Marcel Schloz</a>, <a href="/search/physics?searchtype=author&query=Pisanty%2C+E">Emilio Pisanty</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1805.02250v1-abstract-short" style="display: inline;"> We develop theoretically and confirm both numerically and experimentally a comprehensive analytical model which describes the propensity rules in the emission of circularly polarized high harmonics by systems driven by two-color counter-rotating fields, a fundamental and its second harmonic. We identify and confirm the three propensity rules responsible for the contrast between the 3N+1 and 3N+2 h… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.02250v1-abstract-full').style.display = 'inline'; document.getElementById('1805.02250v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1805.02250v1-abstract-full" style="display: none;"> We develop theoretically and confirm both numerically and experimentally a comprehensive analytical model which describes the propensity rules in the emission of circularly polarized high harmonics by systems driven by two-color counter-rotating fields, a fundamental and its second harmonic. We identify and confirm the three propensity rules responsible for the contrast between the 3N+1 and 3N+2 harmonic lines in the HHG spectra of noble gas atoms. We demonstrate how these rules depend on the laser parameters and how they can be used in the experiment to shape the polarization properties of the emitted attosecond pulses. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.02250v1-abstract-full').style.display = 'none'; document.getElementById('1805.02250v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 May, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Physical Review A 97 023409 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1803.04187">arXiv:1803.04187</a> <span> [<a href="https://arxiv.org/pdf/1803.04187">pdf</a>, <a href="https://arxiv.org/format/1803.04187">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41567-022-01505-2">10.1038/s41567-022-01505-2 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> All-optical attoclock for imaging tunnelling wavepackets </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Babushkin%2C+I">I. Babushkin</a>, <a href="/search/physics?searchtype=author&query=Galan%2C+A+J">A. J. Galan</a>, <a href="/search/physics?searchtype=author&query=Andrade%2C+J+R+C">J. R. C. Andrade</a>, <a href="/search/physics?searchtype=author&query=Husakou%2C+A">A. Husakou</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">F. Morales</a>, <a href="/search/physics?searchtype=author&query=Kretschmar%2C+M">M. Kretschmar</a>, <a href="/search/physics?searchtype=author&query=Nagy%2C+T">T. Nagy</a>, <a href="/search/physics?searchtype=author&query=Vai%C4%8Daitis%2C+V">V. Vai膷aitis</a>, <a href="/search/physics?searchtype=author&query=Shi%2C+L">L. Shi</a>, <a href="/search/physics?searchtype=author&query=Zuber%2C+D">D. Zuber</a>, <a href="/search/physics?searchtype=author&query=Berg%C3%A9%2C+L">L. Berg茅</a>, <a href="/search/physics?searchtype=author&query=Skupin%2C+S">S. Skupin</a>, <a href="/search/physics?searchtype=author&query=Nikolaeva%2C+I+A">I. A. Nikolaeva</a>, <a href="/search/physics?searchtype=author&query=Panov%2C+N+A">N. A. Panov</a>, <a href="/search/physics?searchtype=author&query=Shipilo%2C+D+E">D. E. Shipilo</a>, <a href="/search/physics?searchtype=author&query=Kosareva%2C+O+G">O. G. Kosareva</a>, <a href="/search/physics?searchtype=author&query=Pfeiffer%2C+A+N">A. N. Pfeiffer</a>, <a href="/search/physics?searchtype=author&query=Demircan%2C+A">A. Demircan</a>, <a href="/search/physics?searchtype=author&query=Vrakking%2C+M+J+J">M. J. J. Vrakking</a>, <a href="/search/physics?searchtype=author&query=Morgner%2C+U">U. Morgner</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">M. Ivanov</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1803.04187v4-abstract-short" style="display: inline;"> Recent experiments on measuring time-delays during tunnelling of cold atoms through an optically created potential barrier are reinvigorating the controversial debate regarding possible time-delays during light-induced tunnelling of an electron from an atom. Compelling theoretical and experimental arguments have been put forward to advocate opposite views, confirming or refuting the existence of f… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1803.04187v4-abstract-full').style.display = 'inline'; document.getElementById('1803.04187v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1803.04187v4-abstract-full" style="display: none;"> Recent experiments on measuring time-delays during tunnelling of cold atoms through an optically created potential barrier are reinvigorating the controversial debate regarding possible time-delays during light-induced tunnelling of an electron from an atom. Compelling theoretical and experimental arguments have been put forward to advocate opposite views, confirming or refuting the existence of finite tunnelling time delays. Yet, such a delay, whether present or not, is but a single quantity characterizing the tunnelling wavepacket; the underlying dynamics are richer. Here we propose to augment photo-electron detection in laser-induced tunnelling with detection of light emitted by the tunnelling electron -- the so-called Brunel radiation. Using a combination of single-color and two-color driving fields, we identify the all-optical signatures of the re-shaping of the tunnelling wavepacket as it emerges from the tunnelling barrier and moves away from the core. This reshaping includes not only an effective time-delay but also time-reversal asymmetry of the ionization process, which we describe theoretically and observe experimentally. We show how both delay and reshaping are mapped on the polarization properties of the Brunel radiation, with different harmonics behaving as different hands of a clock moving at different speeds. The all-optical detection paves the way to time-resolving optical tunnelling in condensed matter systems, e.g. tunnelling across bandgaps in solids, on the attosecond time-scale. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1803.04187v4-abstract-full').style.display = 'none'; document.getElementById('1803.04187v4-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 March, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">In the last version, only an acknowledgement has been changed in comparison to the pre-last one</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1802.06630">arXiv:1802.06630</a> <span> [<a href="https://arxiv.org/pdf/1802.06630">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41567-018-0080-5">10.1038/s41567-018-0080-5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ultrafast Preparation and Detection of Ring Currents in Single Atoms </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Eckart%2C+S">Sebastian Eckart</a>, <a href="/search/physics?searchtype=author&query=Kunitski%2C+M">Maksim Kunitski</a>, <a href="/search/physics?searchtype=author&query=Richter%2C+M">Martin Richter</a>, <a href="/search/physics?searchtype=author&query=Hartung%2C+A">Alexander Hartung</a>, <a href="/search/physics?searchtype=author&query=Rist%2C+J">Jonas Rist</a>, <a href="/search/physics?searchtype=author&query=Trinter%2C+F">Florian Trinter</a>, <a href="/search/physics?searchtype=author&query=Fehre%2C+K">Kilian Fehre</a>, <a href="/search/physics?searchtype=author&query=Schlott%2C+N">Nikolai Schlott</a>, <a href="/search/physics?searchtype=author&query=Henrichs%2C+K">Kevin Henrichs</a>, <a href="/search/physics?searchtype=author&query=Schmidt%2C+L+P+H">Lothar Ph. H. Schmidt</a>, <a href="/search/physics?searchtype=author&query=Jahnke%2C+T">Till Jahnke</a>, <a href="/search/physics?searchtype=author&query=Sch%C3%B6ffler%2C+M">Markus Sch枚ffler</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+K">Kunlong Liu</a>, <a href="/search/physics?searchtype=author&query=Barth%2C+I">Ingo Barth</a>, <a href="/search/physics?searchtype=author&query=Kaushal%2C+J">Jivesh Kaushal</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=D%C3%B6rner%2C+R">Reinhard D枚rner</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1802.06630v1-abstract-short" style="display: inline;"> Quantum particles can penetrate potential barriers by tunneling (1). If that barrier is rotating, the tunneling process is modified (2,3). This is typical for electrons in atoms, molecules or solids exposed to strong circularly polarized laser pulses (4,5). Here we measure how the transmission probability through a rotating tunnel depends on the sign of the magnetic quantum number m of the electro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1802.06630v1-abstract-full').style.display = 'inline'; document.getElementById('1802.06630v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1802.06630v1-abstract-full" style="display: none;"> Quantum particles can penetrate potential barriers by tunneling (1). If that barrier is rotating, the tunneling process is modified (2,3). This is typical for electrons in atoms, molecules or solids exposed to strong circularly polarized laser pulses (4,5). Here we measure how the transmission probability through a rotating tunnel depends on the sign of the magnetic quantum number m of the electron and thus on the initial sense of rotation of its quantum phase. We further show that the electron keeps part of that rotary motion on its way through the tunnel by measuring m-dependent modification of the electron emission pattern. These findings are relevant for attosecond metrology as well as for interpretation of strong field electron emission from atoms and molecules (6-13) and directly demonstrates the creation of ring currents in bound states of ions with attosecond precision. In solids, this could open a way to inducing and controlling ring-current related topological phenomena (14). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1802.06630v1-abstract-full').style.display = 'none'; document.getElementById('1802.06630v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 February, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 6 figures, Nature Physics accepted</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nat Phys 14, 701-704 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1707.05590">arXiv:1707.05590</a> <span> [<a href="https://arxiv.org/pdf/1707.05590">pdf</a>, <a href="https://arxiv.org/format/1707.05590">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OE.25.022880">10.1364/OE.25.022880 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Time-resolved high harmonic spectroscopy of dynamical symmetry breaking in bi-circular laser fields </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Jim%C3%A9nez-Gal%C3%A1n%2C+%C3%81">脕lvaro Jim茅nez-Gal谩n</a>, <a href="/search/physics?searchtype=author&query=Zhavoronkov%2C+N">Nickolai Zhavoronkov</a>, <a href="/search/physics?searchtype=author&query=Schloz%2C+M">Marcel Schloz</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1707.05590v1-abstract-short" style="display: inline;"> The bi-circular scheme for high harmonic generation, which combines two counter-rotating circular fields with frequency ratio 2:1, has recently permitted to generate high harmonics with essentially circular polarization, opening the way for ultrafast chiral studies. This scheme produces harmonic lines at 3N + 1 and 3N + 2 multiples of the fundamental driving frequency, while the 3N lines are forbi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.05590v1-abstract-full').style.display = 'inline'; document.getElementById('1707.05590v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1707.05590v1-abstract-full" style="display: none;"> The bi-circular scheme for high harmonic generation, which combines two counter-rotating circular fields with frequency ratio 2:1, has recently permitted to generate high harmonics with essentially circular polarization, opening the way for ultrafast chiral studies. This scheme produces harmonic lines at 3N + 1 and 3N + 2 multiples of the fundamental driving frequency, while the 3N lines are forbidden owing to the three-fold symmetry of the field. It is generally established that the routinely observed signals at these forbidden harmonic lines come from a slight ellipticity in the driving fields, which breaks the three-fold symmetry. We find that this is neither the only nor it is the dominant mechanism responsible. The forbidden lines can be observed even for perfectly circular, long driving pulses. We show that they encode rich information on the sub-cycle electronic dynamics that occur during the generation process. By varying the time delay and relative intensity between the two drivers, we demonstrate that when the second harmonic either precedes or is more intense than the fundamental field, the dynamical symmetry of the system is broken by electrons trapped in Rydberg orbits (i.e., Freeman resonances), and that the forbidden harmonic lines are a witness of this. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.05590v1-abstract-full').style.display = 'none'; document.getElementById('1707.05590v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 July, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2017. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1705.05908">arXiv:1705.05908</a> <span> [<a href="https://arxiv.org/pdf/1705.05908">pdf</a>, <a href="https://arxiv.org/format/1705.05908">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> </div> </div> <p class="title is-5 mathjax"> The Effect of Collective Attention on Controversial Debates on Social Media </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Garimella%2C+K">Kiran Garimella</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Gionis%2C+A">Aristides Gionis</a>, <a href="/search/physics?searchtype=author&query=Mathioudakis%2C+M">Michael Mathioudakis</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1705.05908v1-abstract-short" style="display: inline;"> We study the evolution of long-lived controversial debates as manifested on Twitter from 2011 to 2016. Specifically, we explore how the structure of interactions and content of discussion varies with the level of collective attention, as evidenced by the number of users discussing a topic. Spikes in the volume of users typically correspond to external events that increase the public attention on t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1705.05908v1-abstract-full').style.display = 'inline'; document.getElementById('1705.05908v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1705.05908v1-abstract-full" style="display: none;"> We study the evolution of long-lived controversial debates as manifested on Twitter from 2011 to 2016. Specifically, we explore how the structure of interactions and content of discussion varies with the level of collective attention, as evidenced by the number of users discussing a topic. Spikes in the volume of users typically correspond to external events that increase the public attention on the topic -- as, for instance, discussions about `gun control' often erupt after a mass shooting. This work is the first to study the dynamic evolution of polarized online debates at such scale. By employing a wide array of network and content analysis measures, we find consistent evidence that increased collective attention is associated with increased network polarization and network concentration within each side of the debate; and overall more uniform lexicon usage across all users. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1705.05908v1-abstract-full').style.display = 'none'; document.getElementById('1705.05908v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 May, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">accepted at ACM WebScience 2017</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1703.05994">arXiv:1703.05994</a> <span> [<a href="https://arxiv.org/pdf/1703.05994">pdf</a>, <a href="https://arxiv.org/format/1703.05994">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> </div> </div> <p class="title is-5 mathjax"> The Ebb and Flow of Controversial Debates on Social Media </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Garimella%2C+K">Kiran Garimella</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Gionis%2C+A">Aristides Gionis</a>, <a href="/search/physics?searchtype=author&query=Mathioudakis%2C+M">Michael Mathioudakis</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1703.05994v1-abstract-short" style="display: inline;"> We explore how the polarization around controversial topics evolves on Twitter - over a long period of time (2011 to 2016), and also as a response to major external events that lead to increased related activity. We find that increased activity is typically associated with increased polarization; however, we find no consistent long-term trend in polarization over time among the topics we study. </span> <span class="abstract-full has-text-grey-dark mathjax" id="1703.05994v1-abstract-full" style="display: none;"> We explore how the polarization around controversial topics evolves on Twitter - over a long period of time (2011 to 2016), and also as a response to major external events that lead to increased related activity. We find that increased activity is typically associated with increased polarization; however, we find no consistent long-term trend in polarization over time among the topics we study. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.05994v1-abstract-full').style.display = 'none'; document.getElementById('1703.05994v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 March, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted as a short paper at ICWSM 2017. Please cite the ICWSM version and not the ArXiv version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1702.02778">arXiv:1702.02778</a> <span> [<a href="https://arxiv.org/pdf/1702.02778">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/nphoton.2016.109">10.1038/nphoton.2016.109 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Electron spin polarization in strong-field ionization of Xenon atoms </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Hartung%2C+A">Alexander Hartung</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Kunitski%2C+M">Maksim Kunitski</a>, <a href="/search/physics?searchtype=author&query=Henrichs%2C+K">Kevin Henrichs</a>, <a href="/search/physics?searchtype=author&query=Laucke%2C+A">Alina Laucke</a>, <a href="/search/physics?searchtype=author&query=Richter%2C+M">Martin Richter</a>, <a href="/search/physics?searchtype=author&query=Jahnke%2C+T">Till Jahnke</a>, <a href="/search/physics?searchtype=author&query=Kalinin%2C+A">Anton Kalinin</a>, <a href="/search/physics?searchtype=author&query=Sch%C3%B6ffler%2C+M">Markus Sch枚ffler</a>, <a href="/search/physics?searchtype=author&query=Schmidt%2C+L+P+H">Lothar Ph. H. Schmidt</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a>, <a href="/search/physics?searchtype=author&query=D%C3%B6rner%2C+R">Reinhard D枚rner</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1702.02778v1-abstract-short" style="display: inline;"> As a fundamental property of the electron, the spin plays a decisive role in the electronic structure of matter from solids to molecules and atoms, e.g. causing magnetism. Yet, despite its importance, the spin dynamics of electrons released during the interaction of atoms with strong ultrashort laser pulses has remained unexplored. Here we report on the experimental detection of electron spin pola… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1702.02778v1-abstract-full').style.display = 'inline'; document.getElementById('1702.02778v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1702.02778v1-abstract-full" style="display: none;"> As a fundamental property of the electron, the spin plays a decisive role in the electronic structure of matter from solids to molecules and atoms, e.g. causing magnetism. Yet, despite its importance, the spin dynamics of electrons released during the interaction of atoms with strong ultrashort laser pulses has remained unexplored. Here we report on the experimental detection of electron spin polarization by strong-field ionization of Xenon atoms and support our results by theoretical analysis. We found up to 30% spin polarization changing its sign with electron energy. This work opens the new dimension of spin to strong-field physics. It paves the way to production of subfemtosecond spin polarized electron pulses with applications ranging from probing magnetic properties of matter at ultrafast time scales to testing chiral molecular systems with subfemtosecond temporal and sub-脜ngstr枚m spatial resolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1702.02778v1-abstract-full').style.display = 'none'; document.getElementById('1702.02778v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 February, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Photonics 10 (2016) 526 - 528 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1612.01021">arXiv:1612.01021</a> <span> [<a href="https://arxiv.org/pdf/1612.01021">pdf</a>, <a href="https://arxiv.org/format/1612.01021">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1367-2630/aa732f">10.1088/1367-2630/aa732f <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Attosecond control of spin polarization in electron-ion recollision driven by intense tailored fields </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Ayuso%2C+D">David Ayuso</a>, <a href="/search/physics?searchtype=author&query=Jim%C3%A9nez-Gal%C3%A1n%2C+%C3%81">脕lvaro Jim茅nez-Gal谩n</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1612.01021v2-abstract-short" style="display: inline;"> We show that electrons recolliding with the ionic core upon tunnel ionization of noble gas atoms driven by a strong circularly polarized laser field in combination with a counter-rotating second harmonic are spin polarized and that their degree of polarization depends strongly on the recollision time. Spin polarization arises as a consequence of (1) entanglement between the recolliding electron an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.01021v2-abstract-full').style.display = 'inline'; document.getElementById('1612.01021v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1612.01021v2-abstract-full" style="display: none;"> We show that electrons recolliding with the ionic core upon tunnel ionization of noble gas atoms driven by a strong circularly polarized laser field in combination with a counter-rotating second harmonic are spin polarized and that their degree of polarization depends strongly on the recollision time. Spin polarization arises as a consequence of (1) entanglement between the recolliding electron and the ion, and (2) sensitivity of ionization to the sense of electron rotation in the initial state. We demonstrate that one can engineer the degree of spin polarization as a function of time by tuning the relative intensities of the counter-rotating fields, opening the door for attosecond control of spin-resolved dynamics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.01021v2-abstract-full').style.display = 'none'; document.getElementById('1612.01021v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 December, 2016; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 December, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2016. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1611.09432">arXiv:1611.09432</a> <span> [<a href="https://arxiv.org/pdf/1611.09432">pdf</a>, <a href="https://arxiv.org/format/1611.09432">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Numerical Analysis">math.NA</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Fluid Dynamics">physics.flu-dyn</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1002/mma.4459">10.1002/mma.4459 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Tangential Fluid flow within 3D narrow fissures: Conservative velocity fields on associated triangulations and transport processes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Morales%2C+F+A">Fernando A Morales</a>, <a href="/search/physics?searchtype=author&query=Ram%C3%ADrez%2C+J+M">Jorge M Ram铆rez</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1611.09432v2-abstract-short" style="display: inline;"> For a fissured medium with uncertainty in the knowledge of fractures' geometry, a conservative tangential flow field is constructed, which is consistent with the physics of stationary fluid flow in porous media and an interpolated geometry of the cracks. The flow field permits computing preferential fluid flow directions of the medium, rates of mechanical energy dissipations and a stochastic matri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.09432v2-abstract-full').style.display = 'inline'; document.getElementById('1611.09432v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1611.09432v2-abstract-full" style="display: none;"> For a fissured medium with uncertainty in the knowledge of fractures' geometry, a conservative tangential flow field is constructed, which is consistent with the physics of stationary fluid flow in porous media and an interpolated geometry of the cracks. The flow field permits computing preferential fluid flow directions of the medium, rates of mechanical energy dissipations and a stochastic matrix modeling stream lines and fluid mass transportation, for the analysis of solute/contaminant mass advection-diffusion as well as drainage times. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.09432v2-abstract-full').style.display = 'none'; document.getElementById('1611.09432v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 October, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 November, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 15 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">MSC Class:</span> 76S05; 97M99; 94A17 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Mathematical Methods in the Applied Sciences, 2016 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1611.00172">arXiv:1611.00172</a> <span> [<a href="https://arxiv.org/pdf/1611.00172">pdf</a>, <a href="https://arxiv.org/format/1611.00172">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Social and Information Networks">cs.SI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-ph</span> </div> </div> <p class="title is-5 mathjax"> Reducing Controversy by Connecting Opposing Views </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Garimella%2C+K">Kiran Garimella</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+G+D+F">Gianmarco De Francisci Morales</a>, <a href="/search/physics?searchtype=author&query=Gionis%2C+A">Aristides Gionis</a>, <a href="/search/physics?searchtype=author&query=Mathioudakis%2C+M">Michael Mathioudakis</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1611.00172v3-abstract-short" style="display: inline;"> Society is often polarized by controversial issues, that split the population into groups of opposing views. When such issues emerge on social media, we often observe the creation of 'echo chambers', i.e., situations where like-minded people reinforce each other's opinion, but do not get exposed to the views of the opposing side. In this paper we study algorithmic techniques for bridging these cha… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.00172v3-abstract-full').style.display = 'inline'; document.getElementById('1611.00172v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1611.00172v3-abstract-full" style="display: none;"> Society is often polarized by controversial issues, that split the population into groups of opposing views. When such issues emerge on social media, we often observe the creation of 'echo chambers', i.e., situations where like-minded people reinforce each other's opinion, but do not get exposed to the views of the opposing side. In this paper we study algorithmic techniques for bridging these chambers, and thus, reducing controversy. Specifically, we represent the discussion on a controversial issue with an endorsement graph, and cast our problem as an edge-recommendation problem on this graph. The goal of the recommendation is to reduce the controversy score of the graph, which is measured by a recently-developed metric based on random walks. At the same time, we take into account the acceptance probability of the recommended edge, which represents how likely the edge is to materialize in the endorsement graph. We propose a simple model based on a recently-developed user-level controversy score, that is competitive with state-of- the-art link-prediction algorithms. We thus aim at finding the edges that produce the largest reduction in the controversy score, in expectation. To solve this problem, we propose an efficient algorithm, which considers only a fraction of all the combinations of possible edges. Experimental results show that our algorithm is more efficient than a simple greedy heuristic, while producing comparable score reduction. Finally, a comparison with other state-of-the-art edge-addition algorithms shows that this problem is fundamentally different from what has been studied in the literature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.00172v3-abstract-full').style.display = 'none'; document.getElementById('1611.00172v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 May, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 November, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Proceedings of the Tenth ACM International Conference on Web Search and Data Mining (WSDM 2017)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1607.07275">arXiv:1607.07275</a> <span> [<a href="https://arxiv.org/pdf/1607.07275">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic and Molecular Clusters">physics.atm-clus</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.117.083002">10.1103/PhysRevLett.117.083002 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Two-particle interference of electron pairs on a molecular level </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Waitz%2C+M">M. Waitz</a>, <a href="/search/physics?searchtype=author&query=Metz%2C+D">D. Metz</a>, <a href="/search/physics?searchtype=author&query=Lower%2C+J">J. Lower</a>, <a href="/search/physics?searchtype=author&query=Schober%2C+C">C. Schober</a>, <a href="/search/physics?searchtype=author&query=Keiling%2C+M">M. Keiling</a>, <a href="/search/physics?searchtype=author&query=Pitzer%2C+M">M. Pitzer</a>, <a href="/search/physics?searchtype=author&query=Mertens%2C+K">K. Mertens</a>, <a href="/search/physics?searchtype=author&query=Martins%2C+M">M. Martins</a>, <a href="/search/physics?searchtype=author&query=Viefhaus%2C+J">J. Viefhaus</a>, <a href="/search/physics?searchtype=author&query=Klumpp%2C+S">S. Klumpp</a>, <a href="/search/physics?searchtype=author&query=Weber%2C+T">T. Weber</a>, <a href="/search/physics?searchtype=author&query=Schmidt-B%C3%B6cking%2C+H">H. Schmidt-B枚cking</a>, <a href="/search/physics?searchtype=author&query=Schmidt%2C+L+P+H">L. Ph. H. Schmidt</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">F. Morales</a>, <a href="/search/physics?searchtype=author&query=Miyabe%2C+S">S. Miyabe</a>, <a href="/search/physics?searchtype=author&query=Rescigno%2C+T+N">T. N. Rescigno</a>, <a href="/search/physics?searchtype=author&query=McCurdy%2C+C+W">C. W. McCurdy</a>, <a href="/search/physics?searchtype=author&query=Martin%2C+F">F. Martin</a>, <a href="/search/physics?searchtype=author&query=Williams%2C+J+B">J. B. Williams</a>, <a href="/search/physics?searchtype=author&query=Sch%C3%B6ffler%2C+M+S">M. S. Sch枚ffler</a>, <a href="/search/physics?searchtype=author&query=Jahnke%2C+T">T. Jahnke</a>, <a href="/search/physics?searchtype=author&query=D%C3%B6rner%2C+R">R. D枚rner</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1607.07275v1-abstract-short" style="display: inline;"> We investigate the photo-doubleionization of $H_2$ molecules with 400 eV photons. We find that the emitted electrons do not show any sign of two-center interference fringes in their angular emission distributions if considered separately. In contrast, the quasi-particle consisting of both electrons (i.e. the "dielectron") does. The work highlights the fact that non-local effects are embedded every… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1607.07275v1-abstract-full').style.display = 'inline'; document.getElementById('1607.07275v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1607.07275v1-abstract-full" style="display: none;"> We investigate the photo-doubleionization of $H_2$ molecules with 400 eV photons. We find that the emitted electrons do not show any sign of two-center interference fringes in their angular emission distributions if considered separately. In contrast, the quasi-particle consisting of both electrons (i.e. the "dielectron") does. The work highlights the fact that non-local effects are embedded everywhere in nature where many-particle processes are involved. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1607.07275v1-abstract-full').style.display = 'none'; document.getElementById('1607.07275v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 July, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 117, 083002 (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1606.04566">arXiv:1606.04566</a> <span> [<a href="https://arxiv.org/pdf/1606.04566">pdf</a>, <a href="https://arxiv.org/ps/1606.04566">ps</a>, <a href="https://arxiv.org/format/1606.04566">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Computational Physics">physics.comp-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/0953-4075/49/24/245001">10.1088/0953-4075/49/24/245001 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> iSURF: A family of infinite-time surface flux methods </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Morales%2C+F">F. Morales</a>, <a href="/search/physics?searchtype=author&query=Bredtmann%2C+T">T. Bredtmann</a>, <a href="/search/physics?searchtype=author&query=Patchkovskii%2C+S">S. Patchkovskii</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1606.04566v1-abstract-short" style="display: inline;"> The computation and analysis of photoelectron spectra (PES) is a fundamental technique in atomic and molecular physics to study the structural and dynamical properties of a target system, and to gain insight into the process of its ionization. Since the first numerical solutions of the time-dependent Schr枚dinger equation, numerous methods have been developed to extract PES from the calculated wave… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.04566v1-abstract-full').style.display = 'inline'; document.getElementById('1606.04566v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1606.04566v1-abstract-full" style="display: none;"> The computation and analysis of photoelectron spectra (PES) is a fundamental technique in atomic and molecular physics to study the structural and dynamical properties of a target system, and to gain insight into the process of its ionization. Since the first numerical solutions of the time-dependent Schr枚dinger equation, numerous methods have been developed to extract PES from the calculated wave functions. However, most of these methods have severe limitations or are computationally very demanding. Here we present a new family of methods, based on the ideas of the so-called analytical Volkov continuation, or time-dependent surface flux ([Ermolaev, A. M. et al. Phys. Rev. A 60, 4831 (1999), Ermolaev, A. M. et al. Phys. Rev. A 62, 015401 (2000), Tao L. and Scrinzi A. New Journal of Physics 14, 013021 (2012)]), that allows one to obtain fully-converged PES at the end of the laser pulse using either Volkov states or the exact scattering-states, and that has been implemented in the Time Dependent Schr枚dinger Equation (TDSE) solver ([Patchkovskii S. and Muller H. G., Computer Physics Communications 199, 153 (2016)]). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.04566v1-abstract-full').style.display = 'none'; document.getElementById('1606.04566v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 June, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> J. Phys. B: At. Mol. Opt. Phys. 49 245001 (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1604.01881">arXiv:1604.01881</a> <span> [<a href="https://arxiv.org/pdf/1604.01881">pdf</a>, <a href="https://arxiv.org/ps/1604.01881">ps</a>, <a href="https://arxiv.org/format/1604.01881">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/srep32653">10.1038/srep32653 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Even harmonic generation in isotropic media of dissociating homonuclear molecules </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Silva%2C+R+E+F">R. E. F. Silva</a>, <a href="/search/physics?searchtype=author&query=Rivi%C3%A8re%2C+P">P. Rivi猫re</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">F. Morales</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">O. Smirnova</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">M. Ivanov</a>, <a href="/search/physics?searchtype=author&query=Mart%C3%ADn%2C+F">F. Mart铆n</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1604.01881v1-abstract-short" style="display: inline;"> Isotropic gases irradiated by long pulses of intense IR light can generate very high harmonics of the incident field. It is generally accepted that, due to the symmetry of the generating medium, be it an atomic or an isotropic molecular gas, only odd harmonics of the driving field can be produced. Here we show how the interplay of electronic and nuclear dynamics can lead to a marked breakdown of t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1604.01881v1-abstract-full').style.display = 'inline'; document.getElementById('1604.01881v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1604.01881v1-abstract-full" style="display: none;"> Isotropic gases irradiated by long pulses of intense IR light can generate very high harmonics of the incident field. It is generally accepted that, due to the symmetry of the generating medium, be it an atomic or an isotropic molecular gas, only odd harmonics of the driving field can be produced. Here we show how the interplay of electronic and nuclear dynamics can lead to a marked breakdown of this standard picture: a substantial part of the harmonic spectrum can consist of even rather than odd harmonics. We demonstrate the effect using ab-initio solutions of the time-dependent Schr枚dinger equation for $H$$_2$$^+$ and its isotopes in full dimensionality. By means of a simple analytical model, we identify its physical origin, which is the appearance of a permanent dipole moment in dissociating homonuclear molecules, caused by light-induced localization of the electric charge during dissociation. The effect arises for sufficiently long laser pulses and the region of the spectrum where even harmonics are produced is controlled by pulse duration. Our results (i) show how the interplay of femtosecond nuclear and attosecond electronic dynamics, which affects the charge flow inside the dissociating molecule, is reflected in the nonlinear response, and (ii) force one to augment standard selection rules found in nonlinear optics textbooks by considering light-induced modifications of the medium during the generation process. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1604.01881v1-abstract-full').style.display = 'none'; document.getElementById('1604.01881v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 April, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Scientific Reports 6 (2016) 32653 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1510.01092">arXiv:1510.01092</a> <span> [<a href="https://arxiv.org/pdf/1510.01092">pdf</a>, <a href="https://arxiv.org/format/1510.01092">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.92.063405">10.1103/PhysRevA.92.063405 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Opportunities for detecting ring currents using the attoclock set-up </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Kaushal%2C+J">Jivesh Kaushal</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1510.01092v1-abstract-short" style="display: inline;"> Strong field ionization by circularly polarized laser fields from initial states with internal orbital momentum has interesting propensity rule: electrons counter-rotating with respect to the laser field can be liberated more easily than co-rotating electrons [Barth and Smirnova PRA 84, 063415, 2011}]. Here we show that application of few-cycle IR pulses allows one to use this propensity rule to d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.01092v1-abstract-full').style.display = 'inline'; document.getElementById('1510.01092v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1510.01092v1-abstract-full" style="display: none;"> Strong field ionization by circularly polarized laser fields from initial states with internal orbital momentum has interesting propensity rule: electrons counter-rotating with respect to the laser field can be liberated more easily than co-rotating electrons [Barth and Smirnova PRA 84, 063415, 2011}]. Here we show that application of few-cycle IR pulses allows one to use this propensity rule to detect ring currents associated with such quantum states, by observing angular shifts of the ejected electrons. Such shifts present the main observable of the attoclock method. We use time-dependent Analytical $R$-Matrix (A$R$M) theory to show that the attoclock measured angular shifts of an electron originating from two counter-rotating orbitals ($p^{+}$ and $p^{-}$) are noticeably different. Our work opens new opportunities for detecting ring currents excited in atoms and molecules, using the attoclock set-up. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.01092v1-abstract-full').style.display = 'none'; document.getElementById('1510.01092v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 October, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A 92, 063405 (2015) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1508.00112">arXiv:1508.00112</a> <span> [<a href="https://arxiv.org/pdf/1508.00112">pdf</a>, <a href="https://arxiv.org/format/1508.00112">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Spin-Orbit Larmor Clock for Ionisation Times in One-Photon and Strong-Field Regimes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Kaushal%2C+J">Jivesh Kaushal</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Torlina%2C+L">Lisa Torlina</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1508.00112v3-abstract-short" style="display: inline;"> Photoionisation is a process where absorption of one or several photons liberates an electron and creates a hole in a quantum system, such as an atom or a molecule. Is it faster to remove an electron using one or many photons, and how to define this time? Here we introduce a clock that allows us to define ionisation time for both one-photon and many-photon ionisation regimes. The clock uses the in… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1508.00112v3-abstract-full').style.display = 'inline'; document.getElementById('1508.00112v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1508.00112v3-abstract-full" style="display: none;"> Photoionisation is a process where absorption of one or several photons liberates an electron and creates a hole in a quantum system, such as an atom or a molecule. Is it faster to remove an electron using one or many photons, and how to define this time? Here we introduce a clock that allows us to define ionisation time for both one-photon and many-photon ionisation regimes. The clock uses the interaction of the electron or hole spin with the magnetic field created by their orbital motion, known as the spin-orbit interaction. The angle of spin precession in the magnetic field records time. We use the combination of analytical theory and ab-initio calculations to show how ionisation delay depends on the number of absorbed photons, how it appears in the experiment and what electron dynamics it signifies. In particular, we apply our method to calculate the derived time delays in tunnelling regime of strong-field ionisation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1508.00112v3-abstract-full').style.display = 'none'; document.getElementById('1508.00112v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 September, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 August, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2015. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1506.01798">arXiv:1506.01798</a> <span> [<a href="https://arxiv.org/pdf/1506.01798">pdf</a>, <a href="https://arxiv.org/ps/1506.01798">ps</a>, <a href="https://arxiv.org/format/1506.01798">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1002/2015RS005711">10.1002/2015RS005711 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Power spectrum analysis of ionospheric fluctuations with the Murchison Widefield Array </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Loi%2C+S+T">Shyeh Tjing Loi</a>, <a href="/search/physics?searchtype=author&query=Trott%2C+C+M">Cathryn M. Trott</a>, <a href="/search/physics?searchtype=author&query=Murphy%2C+T">Tara Murphy</a>, <a href="/search/physics?searchtype=author&query=Cairns%2C+I+H">Iver H. Cairns</a>, <a href="/search/physics?searchtype=author&query=Bell%2C+M">Martin Bell</a>, <a href="/search/physics?searchtype=author&query=Hurley-Walker%2C+N">Natasha Hurley-Walker</a>, <a href="/search/physics?searchtype=author&query=Morgan%2C+J">John Morgan</a>, <a href="/search/physics?searchtype=author&query=Lenc%2C+E">Emil Lenc</a>, <a href="/search/physics?searchtype=author&query=Offringa%2C+A+R">A. R. Offringa</a>, <a href="/search/physics?searchtype=author&query=Feng%2C+L">L. Feng</a>, <a href="/search/physics?searchtype=author&query=Hancock%2C+P+J">P. J. Hancock</a>, <a href="/search/physics?searchtype=author&query=Kaplan%2C+D+L">D. L. Kaplan</a>, <a href="/search/physics?searchtype=author&query=Kudryavtseva%2C+N">N. Kudryavtseva</a>, <a href="/search/physics?searchtype=author&query=Bernardi%2C+G">G. Bernardi</a>, <a href="/search/physics?searchtype=author&query=Bowman%2C+J+D">J. D. Bowman</a>, <a href="/search/physics?searchtype=author&query=Briggs%2C+F">F. Briggs</a>, <a href="/search/physics?searchtype=author&query=Cappallo%2C+R+J">R. J. Cappallo</a>, <a href="/search/physics?searchtype=author&query=Corey%2C+B+E">B. E. Corey</a>, <a href="/search/physics?searchtype=author&query=Deshpande%2C+A+A">A. A. Deshpande</a>, <a href="/search/physics?searchtype=author&query=Emrich%2C+D">D. Emrich</a>, <a href="/search/physics?searchtype=author&query=Gaensler%2C+B+M">B. M. Gaensler</a>, <a href="/search/physics?searchtype=author&query=Goeke%2C+R">R. Goeke</a>, <a href="/search/physics?searchtype=author&query=Greenhill%2C+L+J">L. J. Greenhill</a>, <a href="/search/physics?searchtype=author&query=Hazelton%2C+B+J">B. J. Hazelton</a>, <a href="/search/physics?searchtype=author&query=Johnston-Hollitt%2C+M">M. Johnston-Hollitt</a> , et al. (23 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1506.01798v1-abstract-short" style="display: inline;"> Low-frequency, wide field-of-view (FoV) radio telescopes such as the Murchison Widefield Array (MWA) enable the ionosphere to be sampled at high spatial completeness. We present the results of the first power spectrum analysis of ionospheric fluctuations in MWA data, where we examined the position offsets of radio sources appearing in two datasets. The refractive shifts in the positions of celesti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1506.01798v1-abstract-full').style.display = 'inline'; document.getElementById('1506.01798v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1506.01798v1-abstract-full" style="display: none;"> Low-frequency, wide field-of-view (FoV) radio telescopes such as the Murchison Widefield Array (MWA) enable the ionosphere to be sampled at high spatial completeness. We present the results of the first power spectrum analysis of ionospheric fluctuations in MWA data, where we examined the position offsets of radio sources appearing in two datasets. The refractive shifts in the positions of celestial sources are proportional to spatial gradients in the electron column density transverse to the line of sight. These can be used to probe plasma structures and waves in the ionosphere. The regional (10-100 km) scales probed by the MWA, determined by the size of its FoV and the spatial density of radio sources (typically thousands in a single FoV), complement the global (100-1000 km) scales of GPS studies and local (0.01-1 km) scales of radar scattering measurements. Our data exhibit a range of complex structures and waves. Some fluctuations have the characteristics of travelling ionospheric disturbances (TIDs), while others take the form of narrow, slowly-drifting bands aligned along the Earth's magnetic field. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1506.01798v1-abstract-full').style.display = 'none'; document.getElementById('1506.01798v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 June, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Radio Science</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1504.06470">arXiv:1504.06470</a> <span> [<a href="https://arxiv.org/pdf/1504.06470">pdf</a>, <a href="https://arxiv.org/ps/1504.06470">ps</a>, <a href="https://arxiv.org/format/1504.06470">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> Real-time imaging of density ducts between the plasmasphere and ionosphere </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Loi%2C+S+T">Shyeh Tjing Loi</a>, <a href="/search/physics?searchtype=author&query=Murphy%2C+T">Tara Murphy</a>, <a href="/search/physics?searchtype=author&query=Cairns%2C+I+H">Iver H. Cairns</a>, <a href="/search/physics?searchtype=author&query=Menk%2C+F+W">Frederick W. Menk</a>, <a href="/search/physics?searchtype=author&query=Waters%2C+C+L">Colin L. Waters</a>, <a href="/search/physics?searchtype=author&query=Erickson%2C+P+J">Philip J. Erickson</a>, <a href="/search/physics?searchtype=author&query=Trott%2C+C+M">Cathryn M. Trott</a>, <a href="/search/physics?searchtype=author&query=Hurley-Walker%2C+N">Natasha Hurley-Walker</a>, <a href="/search/physics?searchtype=author&query=Morgan%2C+J">John Morgan</a>, <a href="/search/physics?searchtype=author&query=Lenc%2C+E">Emil Lenc</a>, <a href="/search/physics?searchtype=author&query=Offringa%2C+A+R">Andre R. Offringa</a>, <a href="/search/physics?searchtype=author&query=Bell%2C+M+E">Martin E. Bell</a>, <a href="/search/physics?searchtype=author&query=Ekers%2C+R+D">Ronald D. Ekers</a>, <a href="/search/physics?searchtype=author&query=Gaensler%2C+B+M">B. M. Gaensler</a>, <a href="/search/physics?searchtype=author&query=Lonsdale%2C+C+J">Colin J. Lonsdale</a>, <a href="/search/physics?searchtype=author&query=Feng%2C+L">Lu Feng</a>, <a href="/search/physics?searchtype=author&query=Hancock%2C+P+J">Paul J. Hancock</a>, <a href="/search/physics?searchtype=author&query=Kaplan%2C+D+L">David L. Kaplan</a>, <a href="/search/physics?searchtype=author&query=Bernardi%2C+G">G. Bernardi</a>, <a href="/search/physics?searchtype=author&query=Bowman%2C+J+D">J. D. Bowman</a>, <a href="/search/physics?searchtype=author&query=Briggs%2C+F">F. Briggs</a>, <a href="/search/physics?searchtype=author&query=Cappallo%2C+R+J">R. J. Cappallo</a>, <a href="/search/physics?searchtype=author&query=Deshpande%2C+A+A">A. A. Deshpande</a>, <a href="/search/physics?searchtype=author&query=Greenhill%2C+L+J">L. J. Greenhill</a>, <a href="/search/physics?searchtype=author&query=Hazelton%2C+B+J">B. J. Hazelton</a> , et al. (16 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1504.06470v1-abstract-short" style="display: inline;"> Ionization of the Earth's atmosphere by sunlight forms a complex, multi-layered plasma environment within the Earth's magnetosphere, the innermost layers being the ionosphere and plasmasphere. The plasmasphere is believed to be embedded with cylindrical density structures (ducts) aligned along the Earth's magnetic field, but direct evidence for these remains scarce. Here we report the first direct… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1504.06470v1-abstract-full').style.display = 'inline'; document.getElementById('1504.06470v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1504.06470v1-abstract-full" style="display: none;"> Ionization of the Earth's atmosphere by sunlight forms a complex, multi-layered plasma environment within the Earth's magnetosphere, the innermost layers being the ionosphere and plasmasphere. The plasmasphere is believed to be embedded with cylindrical density structures (ducts) aligned along the Earth's magnetic field, but direct evidence for these remains scarce. Here we report the first direct wide-angle observation of an extensive array of field-aligned ducts bridging the upper ionosphere and inner plasmasphere, using a novel ground-based imaging technique. We establish their heights and motions by feature-tracking and parallax analysis. The structures are strikingly organized, appearing as regularly-spaced, alternating tubes of overdensities and underdensities strongly aligned with the Earth's magnetic field. These findings represent the first direct visual evidence for the existence of such structures. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1504.06470v1-abstract-full').style.display = 'none'; document.getElementById('1504.06470v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 April, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Geophysical Research Letters</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1402.5620">arXiv:1402.5620</a> <span> [<a href="https://arxiv.org/pdf/1402.5620">pdf</a>, <a href="https://arxiv.org/format/1402.5620">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Interpreting Attoclock Measurements of Tunnelling Times </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Torlina%2C+L">Lisa Torlina</a>, <a href="/search/physics?searchtype=author&query=Morales%2C+F">Felipe Morales</a>, <a href="/search/physics?searchtype=author&query=Kaushal%2C+J">Jivesh Kaushal</a>, <a href="/search/physics?searchtype=author&query=Muller%2C+H+G">Harm Geert Muller</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+I">Igor Ivanov</a>, <a href="/search/physics?searchtype=author&query=Kheifets%2C+A">Anatoli Kheifets</a>, <a href="/search/physics?searchtype=author&query=Zielinski%2C+A">Alejandro Zielinski</a>, <a href="/search/physics?searchtype=author&query=Scrinzi%2C+A">Armin Scrinzi</a>, <a href="/search/physics?searchtype=author&query=Sukiasyan%2C+S">Suren Sukiasyan</a>, <a href="/search/physics?searchtype=author&query=Ivanov%2C+M">Misha Ivanov</a>, <a href="/search/physics?searchtype=author&query=Smirnova%2C+O">Olga Smirnova</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1402.5620v2-abstract-short" style="display: inline;"> Resolving in time the dynamics of light absorption by atoms and molecules, and the electronic rearrangement this induces, is among the most challenging goals of attosecond spectroscopy. The attoclock is an elegant approach to this problem, which encodes ionization times in the strong-field regime. However, the accurate reconstruction of these times from experimental data presents a formidable theo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1402.5620v2-abstract-full').style.display = 'inline'; document.getElementById('1402.5620v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1402.5620v2-abstract-full" style="display: none;"> Resolving in time the dynamics of light absorption by atoms and molecules, and the electronic rearrangement this induces, is among the most challenging goals of attosecond spectroscopy. The attoclock is an elegant approach to this problem, which encodes ionization times in the strong-field regime. However, the accurate reconstruction of these times from experimental data presents a formidable theoretical challenge. Here, we solve this problem by combining analytical theory with ab-initio numerical simulations. We apply our theory to numerical attoclock experiments on the hydrogen atom to extract ionization time delays and analyse their nature. Strong field ionization is often viewed as optical tunnelling through the barrier created by the field and the core potential. We show that, in the hydrogen atom, optical tunnelling is instantaneous. By calibrating the attoclock using the hydrogen atom, our method opens the way to identify possible delays associated with multielectron dynamics during strong-field ionization. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1402.5620v2-abstract-full').style.display = 'none'; document.getElementById('1402.5620v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 February, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 February, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">33 pages, 10 figures, 3 appendixes</span> </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Morales%2C+F&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Morales%2C+F&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Morales%2C+F&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" aria-label="Secondary">  <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/about">About</a></li> 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