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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <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/2410.06557">arXiv:2410.06557</a> <span> [<a href="https://arxiv.org/pdf/2410.06557">pdf</a>, <a href="https://arxiv.org/format/2410.06557">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="Disordered Systems and Neural Networks">cond-mat.dis-nn</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="High Energy Physics - Lattice">hep-lat</span> </div> </div> <p class="title is-5 mathjax"> Observation of disorder-free localization and efficient disorder averaging on a quantum processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Gyawali%2C+G">Gaurav Gyawali</a>, <a href="/search/cond-mat?searchtype=author&query=Cochran%2C+T">Tyler Cochran</a>, <a href="/search/cond-mat?searchtype=author&query=Lensky%2C+Y">Yuri Lensky</a>, <a href="/search/cond-mat?searchtype=author&query=Rosenberg%2C+E">Eliott Rosenberg</a>, <a href="/search/cond-mat?searchtype=author&query=Karamlou%2C+A+H">Amir H. Karamlou</a>, <a href="/search/cond-mat?searchtype=author&query=Kechedzhi%2C+K">Kostyantyn Kechedzhi</a>, <a href="/search/cond-mat?searchtype=author&query=Berndtsson%2C+J">Julia Berndtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Westerhout%2C+T">Tom Westerhout</a>, <a href="/search/cond-mat?searchtype=author&query=Asfaw%2C+A">Abraham Asfaw</a>, <a href="/search/cond-mat?searchtype=author&query=Abanin%2C+D">Dmitry Abanin</a>, <a href="/search/cond-mat?searchtype=author&query=Acharya%2C+R">Rajeev Acharya</a>, <a href="/search/cond-mat?searchtype=author&query=Beni%2C+L+A">Laleh Aghababaie Beni</a>, <a href="/search/cond-mat?searchtype=author&query=Andersen%2C+T+I">Trond I. Andersen</a>, <a href="/search/cond-mat?searchtype=author&query=Ansmann%2C+M">Markus Ansmann</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">Frank Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">Kunal Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Astrakhantsev%2C+N">Nikita Astrakhantsev</a>, <a href="/search/cond-mat?searchtype=author&query=Atalaya%2C+J">Juan Atalaya</a>, <a href="/search/cond-mat?searchtype=author&query=Babbush%2C+R">Ryan Babbush</a>, <a href="/search/cond-mat?searchtype=author&query=Ballard%2C+B">Brian Ballard</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">Joseph C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Bilmes%2C+A">Alexander Bilmes</a>, <a href="/search/cond-mat?searchtype=author&query=Bortoli%2C+G">Gina Bortoli</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a> , et al. (195 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="2410.06557v1-abstract-short" style="display: inline;"> One of the most challenging problems in the computational study of localization in quantum manybody systems is to capture the effects of rare events, which requires sampling over exponentially many disorder realizations. We implement an efficient procedure on a quantum processor, leveraging quantum parallelism, to efficiently sample over all disorder realizations. We observe localization without d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.06557v1-abstract-full').style.display = 'inline'; document.getElementById('2410.06557v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.06557v1-abstract-full" style="display: none;"> One of the most challenging problems in the computational study of localization in quantum manybody systems is to capture the effects of rare events, which requires sampling over exponentially many disorder realizations. We implement an efficient procedure on a quantum processor, leveraging quantum parallelism, to efficiently sample over all disorder realizations. We observe localization without disorder in quantum many-body dynamics in one and two dimensions: perturbations do not diffuse even though both the generator of evolution and the initial states are fully translationally invariant. The disorder strength as well as its density can be readily tuned using the initial state. Furthermore, we demonstrate the versatility of our platform by measuring Renyi entropies. Our method could also be extended to higher moments of the physical observables and disorder learning. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.06557v1-abstract-full').style.display = 'none'; document.getElementById('2410.06557v1-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 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.17142">arXiv:2409.17142</a> <span> [<a href="https://arxiv.org/pdf/2409.17142">pdf</a>, <a href="https://arxiv.org/format/2409.17142">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="High Energy Physics - Lattice">hep-lat</span> </div> </div> <p class="title is-5 mathjax"> Visualizing Dynamics of Charges and Strings in (2+1)D Lattice Gauge Theories </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Cochran%2C+T+A">Tyler A. Cochran</a>, <a href="/search/cond-mat?searchtype=author&query=Jobst%2C+B">Bernhard Jobst</a>, <a href="/search/cond-mat?searchtype=author&query=Rosenberg%2C+E">Eliott Rosenberg</a>, <a href="/search/cond-mat?searchtype=author&query=Lensky%2C+Y+D">Yuri D. Lensky</a>, <a href="/search/cond-mat?searchtype=author&query=Gyawali%2C+G">Gaurav Gyawali</a>, <a href="/search/cond-mat?searchtype=author&query=Eassa%2C+N">Norhan Eassa</a>, <a href="/search/cond-mat?searchtype=author&query=Will%2C+M">Melissa Will</a>, <a href="/search/cond-mat?searchtype=author&query=Abanin%2C+D">Dmitry Abanin</a>, <a href="/search/cond-mat?searchtype=author&query=Acharya%2C+R">Rajeev Acharya</a>, <a href="/search/cond-mat?searchtype=author&query=Beni%2C+L+A">Laleh Aghababaie Beni</a>, <a href="/search/cond-mat?searchtype=author&query=Andersen%2C+T+I">Trond I. Andersen</a>, <a href="/search/cond-mat?searchtype=author&query=Ansmann%2C+M">Markus Ansmann</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">Frank Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">Kunal Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Asfaw%2C+A">Abraham Asfaw</a>, <a href="/search/cond-mat?searchtype=author&query=Atalaya%2C+J">Juan Atalaya</a>, <a href="/search/cond-mat?searchtype=author&query=Babbush%2C+R">Ryan Babbush</a>, <a href="/search/cond-mat?searchtype=author&query=Ballard%2C+B">Brian Ballard</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">Joseph C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Bilmes%2C+A">Alexander Bilmes</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a>, <a href="/search/cond-mat?searchtype=author&query=Bovaird%2C+J">Jenna Bovaird</a>, <a href="/search/cond-mat?searchtype=author&query=Broughton%2C+M">Michael Broughton</a>, <a href="/search/cond-mat?searchtype=author&query=Browne%2C+D+A">David A. Browne</a> , et al. (167 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="2409.17142v1-abstract-short" style="display: inline;"> Lattice gauge theories (LGTs) can be employed to understand a wide range of phenomena, from elementary particle scattering in high-energy physics to effective descriptions of many-body interactions in materials. Studying dynamical properties of emergent phases can be challenging as it requires solving many-body problems that are generally beyond perturbative limits. We investigate the dynamics of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.17142v1-abstract-full').style.display = 'inline'; document.getElementById('2409.17142v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.17142v1-abstract-full" style="display: none;"> Lattice gauge theories (LGTs) can be employed to understand a wide range of phenomena, from elementary particle scattering in high-energy physics to effective descriptions of many-body interactions in materials. Studying dynamical properties of emergent phases can be challenging as it requires solving many-body problems that are generally beyond perturbative limits. We investigate the dynamics of local excitations in a $\mathbb{Z}_2$ LGT using a two-dimensional lattice of superconducting qubits. We first construct a simple variational circuit which prepares low-energy states that have a large overlap with the ground state; then we create particles with local gates and simulate their quantum dynamics via a discretized time evolution. As the effective magnetic field is increased, our measurements show signatures of transitioning from deconfined to confined dynamics. For confined excitations, the magnetic field induces a tension in the string connecting them. Our method allows us to experimentally image string dynamics in a (2+1)D LGT from which we uncover two distinct regimes inside the confining phase: for weak confinement the string fluctuates strongly in the transverse direction, while for strong confinement transverse fluctuations are effectively frozen. In addition, we demonstrate a resonance condition at which dynamical string breaking is facilitated. Our LGT implementation on a quantum processor presents a novel set of techniques for investigating emergent particle and string dynamics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.17142v1-abstract-full').style.display = 'none'; document.getElementById('2409.17142v1-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 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.04891">arXiv:2406.04891</a> <span> [<a href="https://arxiv.org/pdf/2406.04891">pdf</a>, <a href="https://arxiv.org/format/2406.04891">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="Superconductivity">cond-mat.supr-con</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Dispersive Qubit Readout with Intrinsic Resonator Reset </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Jerger%2C+M">M. Jerger</a>, <a href="/search/cond-mat?searchtype=author&query=Motzoi%2C+F">F. Motzoi</a>, <a href="/search/cond-mat?searchtype=author&query=Gao%2C+Y">Y. Gao</a>, <a href="/search/cond-mat?searchtype=author&query=Dickel%2C+C">C. Dickel</a>, <a href="/search/cond-mat?searchtype=author&query=Buchmann%2C+L">L. Buchmann</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">A. Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Tancredi%2C+G">G. Tancredi</a>, <a href="/search/cond-mat?searchtype=author&query=Warren%2C+C+W">C. W. Warren</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">J. Bylander</a>, <a href="/search/cond-mat?searchtype=author&query=DiVincenzo%2C+D">D. DiVincenzo</a>, <a href="/search/cond-mat?searchtype=author&query=Barends%2C+R">R. Barends</a>, <a href="/search/cond-mat?searchtype=author&query=Bushev%2C+P+A">P. A. Bushev</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="2406.04891v2-abstract-short" style="display: inline;"> A key challenge in quantum computing is speeding up measurement and initialization. Here, we experimentally demonstrate a dispersive measurement method for superconducting qubits that simultaneously measures the qubit and returns the readout resonator to its initial state. The approach is based on universal analytical pulses and requires knowledge of the qubit and resonator parameters, but needs n… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.04891v2-abstract-full').style.display = 'inline'; document.getElementById('2406.04891v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.04891v2-abstract-full" style="display: none;"> A key challenge in quantum computing is speeding up measurement and initialization. Here, we experimentally demonstrate a dispersive measurement method for superconducting qubits that simultaneously measures the qubit and returns the readout resonator to its initial state. The approach is based on universal analytical pulses and requires knowledge of the qubit and resonator parameters, but needs no direct optimization of the pulse shape, even when accounting for the nonlinearity of the system. Moreover, the method generalizes to measuring an arbitrary number of modes and states. For the qubit readout, we can drive the resonator to $\sim 10^2$ photons and back to $\sim 10^{-3}$ photons in less than $3 魏^{-1}$, while still achieving a $T_1$-limited assignment error below 1\%. We also present universal pulse shapes and experimental results for qutrit readout. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.04891v2-abstract-full').style.display = 'none'; document.getElementById('2406.04891v2-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 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">8 pages, 6 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/2405.17385">arXiv:2405.17385</a> <span> [<a href="https://arxiv.org/pdf/2405.17385">pdf</a>, <a href="https://arxiv.org/format/2405.17385">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> </div> <p class="title is-5 mathjax"> Thermalization and Criticality on an Analog-Digital Quantum Simulator </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Andersen%2C+T+I">Trond I. Andersen</a>, <a href="/search/cond-mat?searchtype=author&query=Astrakhantsev%2C+N">Nikita Astrakhantsev</a>, <a href="/search/cond-mat?searchtype=author&query=Karamlou%2C+A+H">Amir H. Karamlou</a>, <a href="/search/cond-mat?searchtype=author&query=Berndtsson%2C+J">Julia Berndtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Motruk%2C+J">Johannes Motruk</a>, <a href="/search/cond-mat?searchtype=author&query=Szasz%2C+A">Aaron Szasz</a>, <a href="/search/cond-mat?searchtype=author&query=Gross%2C+J+A">Jonathan A. Gross</a>, <a href="/search/cond-mat?searchtype=author&query=Schuckert%2C+A">Alexander Schuckert</a>, <a href="/search/cond-mat?searchtype=author&query=Westerhout%2C+T">Tom Westerhout</a>, <a href="/search/cond-mat?searchtype=author&query=Zhang%2C+Y">Yaxing Zhang</a>, <a href="/search/cond-mat?searchtype=author&query=Forati%2C+E">Ebrahim Forati</a>, <a href="/search/cond-mat?searchtype=author&query=Rossi%2C+D">Dario Rossi</a>, <a href="/search/cond-mat?searchtype=author&query=Kobrin%2C+B">Bryce Kobrin</a>, <a href="/search/cond-mat?searchtype=author&query=Di+Paolo%2C+A">Agustin Di Paolo</a>, <a href="/search/cond-mat?searchtype=author&query=Klots%2C+A+R">Andrey R. Klots</a>, <a href="/search/cond-mat?searchtype=author&query=Drozdov%2C+I">Ilya Drozdov</a>, <a href="/search/cond-mat?searchtype=author&query=Kurilovich%2C+V+D">Vladislav D. Kurilovich</a>, <a href="/search/cond-mat?searchtype=author&query=Petukhov%2C+A">Andre Petukhov</a>, <a href="/search/cond-mat?searchtype=author&query=Ioffe%2C+L+B">Lev B. Ioffe</a>, <a href="/search/cond-mat?searchtype=author&query=Elben%2C+A">Andreas Elben</a>, <a href="/search/cond-mat?searchtype=author&query=Rath%2C+A">Aniket Rath</a>, <a href="/search/cond-mat?searchtype=author&query=Vitale%2C+V">Vittorio Vitale</a>, <a href="/search/cond-mat?searchtype=author&query=Vermersch%2C+B">Benoit Vermersch</a>, <a href="/search/cond-mat?searchtype=author&query=Acharya%2C+R">Rajeev Acharya</a>, <a href="/search/cond-mat?searchtype=author&query=Beni%2C+L+A">Laleh Aghababaie Beni</a> , et al. (202 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="2405.17385v2-abstract-short" style="display: inline;"> Understanding how interacting particles approach thermal equilibrium is a major challenge of quantum simulators. Unlocking the full potential of such systems toward this goal requires flexible initial state preparation, precise time evolution, and extensive probes for final state characterization. We present a quantum simulator comprising 69 superconducting qubits which supports both universal qua… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.17385v2-abstract-full').style.display = 'inline'; document.getElementById('2405.17385v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.17385v2-abstract-full" style="display: none;"> Understanding how interacting particles approach thermal equilibrium is a major challenge of quantum simulators. Unlocking the full potential of such systems toward this goal requires flexible initial state preparation, precise time evolution, and extensive probes for final state characterization. We present a quantum simulator comprising 69 superconducting qubits which supports both universal quantum gates and high-fidelity analog evolution, with performance beyond the reach of classical simulation in cross-entropy benchmarking experiments. Emulating a two-dimensional (2D) XY quantum magnet, we leverage a wide range of measurement techniques to study quantum states after ramps from an antiferromagnetic initial state. We observe signatures of the classical Kosterlitz-Thouless phase transition, as well as strong deviations from Kibble-Zurek scaling predictions attributed to the interplay between quantum and classical coarsening of the correlated domains. This interpretation is corroborated by injecting variable energy density into the initial state, which enables studying the effects of the eigenstate thermalization hypothesis (ETH) in targeted parts of the eigenspectrum. Finally, we digitally prepare the system in pairwise-entangled dimer states and image the transport of energy and vorticity during thermalization. These results establish the efficacy of superconducting analog-digital quantum processors for preparing states across many-body spectra and unveiling their thermalization dynamics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.17385v2-abstract-full').style.display = 'none'; document.getElementById('2405.17385v2-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 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.02079">arXiv:2308.02079</a> <span> [<a href="https://arxiv.org/pdf/2308.02079">pdf</a>, <a href="https://arxiv.org/format/2308.02079">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="Superconductivity">cond-mat.supr-con</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.132.100603">10.1103/PhysRevLett.132.100603 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Model-based Optimization of Superconducting Qubit Readout </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Opremcak%2C+A">Alex Opremcak</a>, <a href="/search/cond-mat?searchtype=author&query=Khezri%2C+M">Mostafa Khezri</a>, <a href="/search/cond-mat?searchtype=author&query=Sank%2C+D">Daniel Sank</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a>, <a href="/search/cond-mat?searchtype=author&query=Satzinger%2C+K+J">Kevin J. Satzinger</a>, <a href="/search/cond-mat?searchtype=author&query=Hong%2C+S">Sabrina Hong</a>, <a href="/search/cond-mat?searchtype=author&query=Erickson%2C+C">Catherine Erickson</a>, <a href="/search/cond-mat?searchtype=author&query=Lester%2C+B+J">Brian J. Lester</a>, <a href="/search/cond-mat?searchtype=author&query=Miao%2C+K+C">Kevin C. Miao</a>, <a href="/search/cond-mat?searchtype=author&query=Korotkov%2C+A+N">Alexander N. Korotkov</a>, <a href="/search/cond-mat?searchtype=author&query=Kelly%2C+J">Julian Kelly</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+Z">Zijun Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Klimov%2C+P+V">Paul V. Klimov</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="2308.02079v2-abstract-short" style="display: inline;"> Measurement is an essential component of quantum algorithms, and for superconducting qubits it is often the most error prone. Here, we demonstrate model-based readout optimization achieving low measurement errors while avoiding detrimental side-effects. For simultaneous and mid-circuit measurements across 17 qubits, we observe 1.5% error per qubit with a 500ns end-to-end duration and minimal exces… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.02079v2-abstract-full').style.display = 'inline'; document.getElementById('2308.02079v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.02079v2-abstract-full" style="display: none;"> Measurement is an essential component of quantum algorithms, and for superconducting qubits it is often the most error prone. Here, we demonstrate model-based readout optimization achieving low measurement errors while avoiding detrimental side-effects. For simultaneous and mid-circuit measurements across 17 qubits, we observe 1.5% error per qubit with a 500ns end-to-end duration and minimal excess reset error from residual resonator photons. We also suppress measurement-induced state transitions achieving a leakage rate limited by natural heating. This technique can scale to hundreds of qubits and be used to enhance the performance of error-correcting codes and near-term applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.02079v2-abstract-full').style.display = 'none'; document.getElementById('2308.02079v2-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 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.04792">arXiv:2303.04792</a> <span> [<a href="https://arxiv.org/pdf/2303.04792">pdf</a>, <a href="https://arxiv.org/format/2303.04792">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="Statistical Mechanics">cond-mat.stat-mech</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Theory">hep-th</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/s41586-023-06505-7">10.1038/s41586-023-06505-7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measurement-induced entanglement and teleportation on a noisy quantum processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Hoke%2C+J+C">Jesse C. Hoke</a>, <a href="/search/cond-mat?searchtype=author&query=Ippoliti%2C+M">Matteo Ippoliti</a>, <a href="/search/cond-mat?searchtype=author&query=Rosenberg%2C+E">Eliott Rosenberg</a>, <a href="/search/cond-mat?searchtype=author&query=Abanin%2C+D">Dmitry Abanin</a>, <a href="/search/cond-mat?searchtype=author&query=Acharya%2C+R">Rajeev Acharya</a>, <a href="/search/cond-mat?searchtype=author&query=Andersen%2C+T+I">Trond I. Andersen</a>, <a href="/search/cond-mat?searchtype=author&query=Ansmann%2C+M">Markus Ansmann</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">Frank Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">Kunal Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Asfaw%2C+A">Abraham Asfaw</a>, <a href="/search/cond-mat?searchtype=author&query=Atalaya%2C+J">Juan Atalaya</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">Joseph C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Bortoli%2C+G">Gina Bortoli</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a>, <a href="/search/cond-mat?searchtype=author&query=Bovaird%2C+J">Jenna Bovaird</a>, <a href="/search/cond-mat?searchtype=author&query=Brill%2C+L">Leon Brill</a>, <a href="/search/cond-mat?searchtype=author&query=Broughton%2C+M">Michael Broughton</a>, <a href="/search/cond-mat?searchtype=author&query=Buckley%2C+B+B">Bob B. Buckley</a>, <a href="/search/cond-mat?searchtype=author&query=Buell%2C+D+A">David A. Buell</a>, <a href="/search/cond-mat?searchtype=author&query=Burger%2C+T">Tim Burger</a>, <a href="/search/cond-mat?searchtype=author&query=Burkett%2C+B">Brian Burkett</a>, <a href="/search/cond-mat?searchtype=author&query=Bushnell%2C+N">Nicholas Bushnell</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+Z">Zijun Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Chiaro%2C+B">Ben Chiaro</a> , et al. (138 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="2303.04792v2-abstract-short" style="display: inline;"> Measurement has a special role in quantum theory: by collapsing the wavefunction it can enable phenomena such as teleportation and thereby alter the "arrow of time" that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space-time that go beyond established paradigms for characterizing phases, either in or out… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.04792v2-abstract-full').style.display = 'inline'; document.getElementById('2303.04792v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.04792v2-abstract-full" style="display: none;"> Measurement has a special role in quantum theory: by collapsing the wavefunction it can enable phenomena such as teleportation and thereby alter the "arrow of time" that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space-time that go beyond established paradigms for characterizing phases, either in or out of equilibrium. On present-day NISQ processors, the experimental realization of this physics is challenging due to noise, hardware limitations, and the stochastic nature of quantum measurement. Here we address each of these experimental challenges and investigate measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping, to avoid mid-circuit measurement and access different manifestations of the underlying phases -- from entanglement scaling to measurement-induced teleportation -- in a unified way. We obtain finite-size signatures of a phase transition with a decoding protocol that correlates the experimental measurement record with classical simulation data. The phases display sharply different sensitivity to noise, which we exploit to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realize measurement-induced physics at scales that are at the limits of current NISQ processors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.04792v2-abstract-full').style.display = 'none'; document.getElementById('2303.04792v2-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 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature 622, 481-486 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.10255">arXiv:2210.10255</a> <span> [<a href="https://arxiv.org/pdf/2210.10255">pdf</a>, <a href="https://arxiv.org/format/2210.10255">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Other Condensed Matter">cond-mat.other</span> </div> </div> <p class="title is-5 mathjax"> Non-Abelian braiding of graph vertices in a superconducting processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Andersen%2C+T+I">Trond I. Andersen</a>, <a href="/search/cond-mat?searchtype=author&query=Lensky%2C+Y+D">Yuri D. Lensky</a>, <a href="/search/cond-mat?searchtype=author&query=Kechedzhi%2C+K">Kostyantyn Kechedzhi</a>, <a href="/search/cond-mat?searchtype=author&query=Drozdov%2C+I">Ilya Drozdov</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Hong%2C+S">Sabrina Hong</a>, <a href="/search/cond-mat?searchtype=author&query=Morvan%2C+A">Alexis Morvan</a>, <a href="/search/cond-mat?searchtype=author&query=Mi%2C+X">Xiao Mi</a>, <a href="/search/cond-mat?searchtype=author&query=Opremcak%2C+A">Alex Opremcak</a>, <a href="/search/cond-mat?searchtype=author&query=Acharya%2C+R">Rajeev Acharya</a>, <a href="/search/cond-mat?searchtype=author&query=Allen%2C+R">Richard Allen</a>, <a href="/search/cond-mat?searchtype=author&query=Ansmann%2C+M">Markus Ansmann</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">Frank Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">Kunal Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Asfaw%2C+A">Abraham Asfaw</a>, <a href="/search/cond-mat?searchtype=author&query=Atalaya%2C+J">Juan Atalaya</a>, <a href="/search/cond-mat?searchtype=author&query=Babbush%2C+R">Ryan Babbush</a>, <a href="/search/cond-mat?searchtype=author&query=Bacon%2C+D">Dave Bacon</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">Joseph C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Bortoli%2C+G">Gina Bortoli</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a>, <a href="/search/cond-mat?searchtype=author&query=Bovaird%2C+J">Jenna Bovaird</a>, <a href="/search/cond-mat?searchtype=author&query=Brill%2C+L">Leon Brill</a>, <a href="/search/cond-mat?searchtype=author&query=Broughton%2C+M">Michael Broughton</a>, <a href="/search/cond-mat?searchtype=author&query=Buckley%2C+B+B">Bob B. Buckley</a> , et al. (144 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="2210.10255v2-abstract-short" style="display: inline;"> Indistinguishability of particles is a fundamental principle of quantum mechanics. For all elementary and quasiparticles observed to date - including fermions, bosons, and Abelian anyons - this principle guarantees that the braiding of identical particles leaves the system unchanged. However, in two spatial dimensions, an intriguing possibility exists: braiding of non-Abelian anyons causes rotatio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.10255v2-abstract-full').style.display = 'inline'; document.getElementById('2210.10255v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.10255v2-abstract-full" style="display: none;"> Indistinguishability of particles is a fundamental principle of quantum mechanics. For all elementary and quasiparticles observed to date - including fermions, bosons, and Abelian anyons - this principle guarantees that the braiding of identical particles leaves the system unchanged. However, in two spatial dimensions, an intriguing possibility exists: braiding of non-Abelian anyons causes rotations in a space of topologically degenerate wavefunctions. Hence, it can change the observables of the system without violating the principle of indistinguishability. Despite the well developed mathematical description of non-Abelian anyons and numerous theoretical proposals, the experimental observation of their exchange statistics has remained elusive for decades. Controllable many-body quantum states generated on quantum processors offer another path for exploring these fundamental phenomena. While efforts on conventional solid-state platforms typically involve Hamiltonian dynamics of quasi-particles, superconducting quantum processors allow for directly manipulating the many-body wavefunction via unitary gates. Building on predictions that stabilizer codes can host projective non-Abelian Ising anyons, we implement a generalized stabilizer code and unitary protocol to create and braid them. This allows us to experimentally verify the fusion rules of the anyons and braid them to realize their statistics. We then study the prospect of employing the anyons for quantum computation and utilize braiding to create an entangled state of anyons encoding three logical qubits. Our work provides new insights about non-Abelian braiding and - through the future inclusion of error correction to achieve topological protection - could open a path toward fault-tolerant quantum computing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.10255v2-abstract-full').style.display = 'none'; document.getElementById('2210.10255v2-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 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.07757">arXiv:2209.07757</a> <span> [<a href="https://arxiv.org/pdf/2209.07757">pdf</a>, <a href="https://arxiv.org/format/2209.07757">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="Superconductivity">cond-mat.supr-con</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/10.1063/5.0127375">10.1063/5.0127375 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Readout of a quantum processor with high dynamic range Josephson parametric amplifiers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=White%2C+T+C">T. C. White</a>, <a href="/search/cond-mat?searchtype=author&query=Opremcak%2C+A">Alex Opremcak</a>, <a href="/search/cond-mat?searchtype=author&query=Sterling%2C+G">George Sterling</a>, <a href="/search/cond-mat?searchtype=author&query=Korotkov%2C+A">Alexander Korotkov</a>, <a href="/search/cond-mat?searchtype=author&query=Sank%2C+D">Daniel Sank</a>, <a href="/search/cond-mat?searchtype=author&query=Acharya%2C+R">Rajeev Acharya</a>, <a href="/search/cond-mat?searchtype=author&query=Ansmann%2C+M">Markus Ansmann</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">Frank Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">Kunal Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">Joseph C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a>, <a href="/search/cond-mat?searchtype=author&query=Bovaird%2C+J">Jenna Bovaird</a>, <a href="/search/cond-mat?searchtype=author&query=Brill%2C+L">Leon Brill</a>, <a href="/search/cond-mat?searchtype=author&query=Buckley%2C+B+B">Bob B. Buckley</a>, <a href="/search/cond-mat?searchtype=author&query=Buell%2C+D+A">David A. Buell</a>, <a href="/search/cond-mat?searchtype=author&query=Burger%2C+T">Tim Burger</a>, <a href="/search/cond-mat?searchtype=author&query=Burkett%2C+B">Brian Burkett</a>, <a href="/search/cond-mat?searchtype=author&query=Bushnell%2C+N">Nicholas Bushnell</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+Z">Zijun Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Chiaro%2C+B">Ben Chiaro</a>, <a href="/search/cond-mat?searchtype=author&query=Cogan%2C+J">Josh Cogan</a>, <a href="/search/cond-mat?searchtype=author&query=Collins%2C+R">Roberto Collins</a>, <a href="/search/cond-mat?searchtype=author&query=Crook%2C+A+L">Alexander L. Crook</a>, <a href="/search/cond-mat?searchtype=author&query=Curtin%2C+B">Ben Curtin</a> , et al. (69 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="2209.07757v2-abstract-short" style="display: inline;"> We demonstrate a high dynamic range Josephson parametric amplifier (JPA) in which the active nonlinear element is implemented using an array of rf-SQUIDs. The device is matched to the 50 $惟$ environment with a Klopfenstein-taper impedance transformer and achieves a bandwidth of 250-300 MHz, with input saturation powers up to -95 dBm at 20 dB gain. A 54-qubit Sycamore processor was used to benchmar… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.07757v2-abstract-full').style.display = 'inline'; document.getElementById('2209.07757v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.07757v2-abstract-full" style="display: none;"> We demonstrate a high dynamic range Josephson parametric amplifier (JPA) in which the active nonlinear element is implemented using an array of rf-SQUIDs. The device is matched to the 50 $惟$ environment with a Klopfenstein-taper impedance transformer and achieves a bandwidth of 250-300 MHz, with input saturation powers up to -95 dBm at 20 dB gain. A 54-qubit Sycamore processor was used to benchmark these devices, providing a calibration for readout power, an estimate of amplifier added noise, and a platform for comparison against standard impedance matched parametric amplifiers with a single dc-SQUID. We find that the high power rf-SQUID array design has no adverse effect on system noise, readout fidelity, or qubit dephasing, and we estimate an upper bound on amplifier added noise at 1.6 times the quantum limit. Lastly, amplifiers with this design show no degradation in readout fidelity due to gain compression, which can occur in multi-tone multiplexed readout with traditional JPAs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.07757v2-abstract-full').style.display = 'none'; document.getElementById('2209.07757v2-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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">10 pages, 10 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Appl. Phys. Lett. 122, 014001 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.05254">arXiv:2206.05254</a> <span> [<a href="https://arxiv.org/pdf/2206.05254">pdf</a>, <a href="https://arxiv.org/format/2206.05254">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Other Condensed Matter">cond-mat.other</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/s41586-022-05348-y">10.1038/s41586-022-05348-y <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Formation of robust bound states of interacting microwave photons </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Morvan%2C+A">Alexis Morvan</a>, <a href="/search/cond-mat?searchtype=author&query=Andersen%2C+T+I">Trond I. Andersen</a>, <a href="/search/cond-mat?searchtype=author&query=Mi%2C+X">Xiao Mi</a>, <a href="/search/cond-mat?searchtype=author&query=Neill%2C+C">Charles Neill</a>, <a href="/search/cond-mat?searchtype=author&query=Petukhov%2C+A">Andre Petukhov</a>, <a href="/search/cond-mat?searchtype=author&query=Kechedzhi%2C+K">Kostyantyn Kechedzhi</a>, <a href="/search/cond-mat?searchtype=author&query=Abanin%2C+D">Dmitry Abanin</a>, <a href="/search/cond-mat?searchtype=author&query=Acharya%2C+R">Rajeev Acharya</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">Frank Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">Kunal Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Asfaw%2C+A">Abraham Asfaw</a>, <a href="/search/cond-mat?searchtype=author&query=Atalaya%2C+J">Juan Atalaya</a>, <a href="/search/cond-mat?searchtype=author&query=Babbush%2C+R">Ryan Babbush</a>, <a href="/search/cond-mat?searchtype=author&query=Bacon%2C+D">Dave Bacon</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">Joseph C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Basso%2C+J">Joao Basso</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Bortoli%2C+G">Gina Bortoli</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a>, <a href="/search/cond-mat?searchtype=author&query=Bovaird%2C+J">Jenna Bovaird</a>, <a href="/search/cond-mat?searchtype=author&query=Brill%2C+L">Leon Brill</a>, <a href="/search/cond-mat?searchtype=author&query=Broughton%2C+M">Michael Broughton</a>, <a href="/search/cond-mat?searchtype=author&query=Buckley%2C+B+B">Bob B. Buckley</a>, <a href="/search/cond-mat?searchtype=author&query=Buell%2C+D+A">David A. Buell</a>, <a href="/search/cond-mat?searchtype=author&query=Burger%2C+T">Tim Burger</a> , et al. (125 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="2206.05254v3-abstract-short" style="display: inline;"> Systems of correlated particles appear in many fields of science and represent some of the most intractable puzzles in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles. The lack of general solutions for the 3-body problem and acceptable theory for strongly cor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.05254v3-abstract-full').style.display = 'inline'; document.getElementById('2206.05254v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.05254v3-abstract-full" style="display: none;"> Systems of correlated particles appear in many fields of science and represent some of the most intractable puzzles in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles. The lack of general solutions for the 3-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multi-particle bound states. In a ring of 24 superconducting qubits, we develop a high fidelity parameterizable fSim gate that we use to implement the periodic quantum circuit of the spin-1/2 XXZ model, an archetypal model of interaction. By placing microwave photons in adjacent qubit sites, we study the propagation of these excitations and observe their bound nature for up to 5 photons. We devise a phase sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the common wisdom that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.05254v3-abstract-full').style.display = 'none'; document.getElementById('2206.05254v3-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> 21 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 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">7 pages + 15 pages supplements</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature 612, 240-245 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.11372">arXiv:2204.11372</a> <span> [<a href="https://arxiv.org/pdf/2204.11372">pdf</a>, <a href="https://arxiv.org/format/2204.11372">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Other Condensed Matter">cond-mat.other</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/10.1126/science.abq5769">10.1126/science.abq5769 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Noise-resilient Edge Modes on a Chain of Superconducting Qubits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Mi%2C+X">Xiao Mi</a>, <a href="/search/cond-mat?searchtype=author&query=Sonner%2C+M">Michael Sonner</a>, <a href="/search/cond-mat?searchtype=author&query=Niu%2C+M+Y">Murphy Yuezhen Niu</a>, <a href="/search/cond-mat?searchtype=author&query=Lee%2C+K+W">Kenneth W. Lee</a>, <a href="/search/cond-mat?searchtype=author&query=Foxen%2C+B">Brooks Foxen</a>, <a href="/search/cond-mat?searchtype=author&query=Acharya%2C+R">Rajeev Acharya</a>, <a href="/search/cond-mat?searchtype=author&query=Aleiner%2C+I">Igor Aleiner</a>, <a href="/search/cond-mat?searchtype=author&query=Andersen%2C+T+I">Trond I. Andersen</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">Frank Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">Kunal Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Asfaw%2C+A">Abraham Asfaw</a>, <a href="/search/cond-mat?searchtype=author&query=Atalaya%2C+J">Juan Atalaya</a>, <a href="/search/cond-mat?searchtype=author&query=Babbush%2C+R">Ryan Babbush</a>, <a href="/search/cond-mat?searchtype=author&query=Bacon%2C+D">Dave Bacon</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">Joseph C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Basso%2C+J">Joao Basso</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Bortoli%2C+G">Gina Bortoli</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a>, <a href="/search/cond-mat?searchtype=author&query=Brill%2C+L">Leon Brill</a>, <a href="/search/cond-mat?searchtype=author&query=Broughton%2C+M">Michael Broughton</a>, <a href="/search/cond-mat?searchtype=author&query=Buckley%2C+B+B">Bob B. Buckley</a>, <a href="/search/cond-mat?searchtype=author&query=Buell%2C+D+A">David A. Buell</a>, <a href="/search/cond-mat?searchtype=author&query=Burkett%2C+B">Brian Burkett</a>, <a href="/search/cond-mat?searchtype=author&query=Bushnell%2C+N">Nicholas Bushnell</a> , et al. (103 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="2204.11372v2-abstract-short" style="display: inline;"> Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the one-dimensional kicked Ising model which exhibits non-local Majorana edge modes (MEMs) with $\mathbb{Z}_2$ parity symmetry. Remarkably, we find that any multi-qub… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.11372v2-abstract-full').style.display = 'inline'; document.getElementById('2204.11372v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.11372v2-abstract-full" style="display: none;"> Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the one-dimensional kicked Ising model which exhibits non-local Majorana edge modes (MEMs) with $\mathbb{Z}_2$ parity symmetry. Remarkably, we find that any multi-qubit Pauli operator overlapping with the MEMs exhibits a uniform late-time decay rate comparable to single-qubit relaxation rates, irrespective of its size or composition. This characteristic allows us to accurately reconstruct the exponentially localized spatial profiles of the MEMs. Furthermore, the MEMs are found to be resilient against certain symmetry-breaking noise owing to a prethermalization mechanism. Our work elucidates the complex interplay between noise and symmetry-protected edge modes in a solid-state environment. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.11372v2-abstract-full').style.display = 'none'; document.getElementById('2204.11372v2-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 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science 378, 785 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.13571">arXiv:2107.13571</a> <span> [<a href="https://arxiv.org/pdf/2107.13571">pdf</a>, <a href="https://arxiv.org/format/2107.13571">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="Disordered Systems and Neural Networks">cond-mat.dis-nn</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</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/s41586-021-04257-w">10.1038/s41586-021-04257-w <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of Time-Crystalline Eigenstate Order on a Quantum Processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Mi%2C+X">Xiao Mi</a>, <a href="/search/cond-mat?searchtype=author&query=Ippoliti%2C+M">Matteo Ippoliti</a>, <a href="/search/cond-mat?searchtype=author&query=Quintana%2C+C">Chris Quintana</a>, <a href="/search/cond-mat?searchtype=author&query=Greene%2C+A">Ami Greene</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+Z">Zijun Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Gross%2C+J">Jonathan Gross</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">Frank Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">Kunal Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Atalaya%2C+J">Juan Atalaya</a>, <a href="/search/cond-mat?searchtype=author&query=Babbush%2C+R">Ryan Babbush</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">Joseph C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Basso%2C+J">Joao Basso</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Bilmes%2C+A">Alexander Bilmes</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a>, <a href="/search/cond-mat?searchtype=author&query=Brill%2C+L">Leon Brill</a>, <a href="/search/cond-mat?searchtype=author&query=Broughton%2C+M">Michael Broughton</a>, <a href="/search/cond-mat?searchtype=author&query=Buckley%2C+B+B">Bob B. Buckley</a>, <a href="/search/cond-mat?searchtype=author&query=Buell%2C+D+A">David A. Buell</a>, <a href="/search/cond-mat?searchtype=author&query=Burkett%2C+B">Brian Burkett</a>, <a href="/search/cond-mat?searchtype=author&query=Bushnell%2C+N">Nicholas Bushnell</a>, <a href="/search/cond-mat?searchtype=author&query=Chiaro%2C+B">Benjamin Chiaro</a>, <a href="/search/cond-mat?searchtype=author&query=Collins%2C+R">Roberto Collins</a>, <a href="/search/cond-mat?searchtype=author&query=Courtney%2C+W">William Courtney</a>, <a href="/search/cond-mat?searchtype=author&query=Debroy%2C+D">Dripto Debroy</a> , et al. (80 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="2107.13571v2-abstract-short" style="display: inline;"> Quantum many-body systems display rich phase structure in their low-temperature equilibrium states. However, much of nature is not in thermal equilibrium. Remarkably, it was recently predicted that out-of-equilibrium systems can exhibit novel dynamical phases that may otherwise be forbidden by equilibrium thermodynamics, a paradigmatic example being the discrete time crystal (DTC). Concretely, dyn… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.13571v2-abstract-full').style.display = 'inline'; document.getElementById('2107.13571v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.13571v2-abstract-full" style="display: none;"> Quantum many-body systems display rich phase structure in their low-temperature equilibrium states. However, much of nature is not in thermal equilibrium. Remarkably, it was recently predicted that out-of-equilibrium systems can exhibit novel dynamical phases that may otherwise be forbidden by equilibrium thermodynamics, a paradigmatic example being the discrete time crystal (DTC). Concretely, dynamical phases can be defined in periodically driven many-body localized systems via the concept of eigenstate order. In eigenstate-ordered phases, the entire many-body spectrum exhibits quantum correlations and long-range order, with characteristic signatures in late-time dynamics from all initial states. It is, however, challenging to experimentally distinguish such stable phases from transient phenomena, wherein few select states can mask typical behavior. Here we implement a continuous family of tunable CPHASE gates on an array of superconducting qubits to experimentally observe an eigenstate-ordered DTC. We demonstrate the characteristic spatiotemporal response of a DTC for generic initial states. Our work employs a time-reversal protocol that discriminates external decoherence from intrinsic thermalization, and leverages quantum typicality to circumvent the exponential cost of densely sampling the eigenspectrum. In addition, we locate the phase transition out of the DTC with an experimental finite-size analysis. These results establish a scalable approach to study non-equilibrium phases of matter on current quantum processors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.13571v2-abstract-full').style.display = 'none'; document.getElementById('2107.13571v2-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> 11 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 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">Journal ref:</span> Nature 601, 531 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.01180">arXiv:2104.01180</a> <span> [<a href="https://arxiv.org/pdf/2104.01180">pdf</a>, <a href="https://arxiv.org/format/2104.01180">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> </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/10.1126/science.abi8378">10.1126/science.abi8378 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Realizing topologically ordered states on a quantum processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Satzinger%2C+K+J">K. J. Satzinger</a>, <a href="/search/cond-mat?searchtype=author&query=Liu%2C+Y">Y. Liu</a>, <a href="/search/cond-mat?searchtype=author&query=Smith%2C+A">A. Smith</a>, <a href="/search/cond-mat?searchtype=author&query=Knapp%2C+C">C. Knapp</a>, <a href="/search/cond-mat?searchtype=author&query=Newman%2C+M">M. Newman</a>, <a href="/search/cond-mat?searchtype=author&query=Jones%2C+C">C. Jones</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+Z">Z. Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Quintana%2C+C">C. Quintana</a>, <a href="/search/cond-mat?searchtype=author&query=Mi%2C+X">X. Mi</a>, <a href="/search/cond-mat?searchtype=author&query=Dunsworth%2C+A">A. Dunsworth</a>, <a href="/search/cond-mat?searchtype=author&query=Gidney%2C+C">C. Gidney</a>, <a href="/search/cond-mat?searchtype=author&query=Aleiner%2C+I">I. Aleiner</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">F. Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">K. Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Atalaya%2C+J">J. Atalaya</a>, <a href="/search/cond-mat?searchtype=author&query=Babbush%2C+R">R. Babbush</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">J. C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Barends%2C+R">R. Barends</a>, <a href="/search/cond-mat?searchtype=author&query=Basso%2C+J">J. Basso</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">A. Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Bilmes%2C+A">A. Bilmes</a>, <a href="/search/cond-mat?searchtype=author&query=Broughton%2C+M">M. Broughton</a>, <a href="/search/cond-mat?searchtype=author&query=Buckley%2C+B+B">B. B. Buckley</a>, <a href="/search/cond-mat?searchtype=author&query=Buell%2C+D+A">D. A. Buell</a>, <a href="/search/cond-mat?searchtype=author&query=Burkett%2C+B">B. Burkett</a> , et al. (73 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="2104.01180v1-abstract-short" style="display: inline;"> The discovery of topological order has revolutionized the understanding of quantum matter in modern physics and provided the theoretical foundation for many quantum error correcting codes. Realizing topologically ordered states has proven to be extremely challenging in both condensed matter and synthetic quantum systems. Here, we prepare the ground state of the toric code Hamiltonian using an effi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.01180v1-abstract-full').style.display = 'inline'; document.getElementById('2104.01180v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.01180v1-abstract-full" style="display: none;"> The discovery of topological order has revolutionized the understanding of quantum matter in modern physics and provided the theoretical foundation for many quantum error correcting codes. Realizing topologically ordered states has proven to be extremely challenging in both condensed matter and synthetic quantum systems. Here, we prepare the ground state of the toric code Hamiltonian using an efficient quantum circuit on a superconducting quantum processor. We measure a topological entanglement entropy near the expected value of $\ln2$, and simulate anyon interferometry to extract the braiding statistics of the emergent excitations. Furthermore, we investigate key aspects of the surface code, including logical state injection and the decay of the non-local order parameter. Our results demonstrate the potential for quantum processors to provide key insights into topological quantum matter and quantum error correction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.01180v1-abstract-full').style.display = 'none'; document.getElementById('2104.01180v1-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 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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 4 figures, plus supplementary materials</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science 374, 1237-1241 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.08870">arXiv:2101.08870</a> <span> [<a href="https://arxiv.org/pdf/2101.08870">pdf</a>, <a href="https://arxiv.org/format/2101.08870">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="High Energy Physics - Theory">hep-th</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/10.1126/science.abg5029">10.1126/science.abg5029 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Information Scrambling in Computationally Complex Quantum Circuits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Mi%2C+X">Xiao Mi</a>, <a href="/search/cond-mat?searchtype=author&query=Roushan%2C+P">Pedram Roushan</a>, <a href="/search/cond-mat?searchtype=author&query=Quintana%2C+C">Chris Quintana</a>, <a href="/search/cond-mat?searchtype=author&query=Mandra%2C+S">Salvatore Mandra</a>, <a href="/search/cond-mat?searchtype=author&query=Marshall%2C+J">Jeffrey Marshall</a>, <a href="/search/cond-mat?searchtype=author&query=Neill%2C+C">Charles Neill</a>, <a href="/search/cond-mat?searchtype=author&query=Arute%2C+F">Frank Arute</a>, <a href="/search/cond-mat?searchtype=author&query=Arya%2C+K">Kunal Arya</a>, <a href="/search/cond-mat?searchtype=author&query=Atalaya%2C+J">Juan Atalaya</a>, <a href="/search/cond-mat?searchtype=author&query=Babbush%2C+R">Ryan Babbush</a>, <a href="/search/cond-mat?searchtype=author&query=Bardin%2C+J+C">Joseph C. Bardin</a>, <a href="/search/cond-mat?searchtype=author&query=Barends%2C+R">Rami Barends</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Boixo%2C+S">Sergio Boixo</a>, <a href="/search/cond-mat?searchtype=author&query=Bourassa%2C+A">Alexandre Bourassa</a>, <a href="/search/cond-mat?searchtype=author&query=Broughton%2C+M">Michael Broughton</a>, <a href="/search/cond-mat?searchtype=author&query=Buckley%2C+B+B">Bob B. Buckley</a>, <a href="/search/cond-mat?searchtype=author&query=Buell%2C+D+A">David A. Buell</a>, <a href="/search/cond-mat?searchtype=author&query=Burkett%2C+B">Brian Burkett</a>, <a href="/search/cond-mat?searchtype=author&query=Bushnell%2C+N">Nicholas Bushnell</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+Z">Zijun Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Chiaro%2C+B">Benjamin Chiaro</a>, <a href="/search/cond-mat?searchtype=author&query=Collins%2C+R">Roberto Collins</a>, <a href="/search/cond-mat?searchtype=author&query=Courtney%2C+W">William Courtney</a>, <a href="/search/cond-mat?searchtype=author&query=Demura%2C+S">Sean Demura</a> , et al. (68 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="2101.08870v1-abstract-short" style="display: inline;"> Interaction in quantum systems can spread initially localized quantum information into the many degrees of freedom of the entire system. Understanding this process, known as quantum scrambling, is the key to resolving various conundrums in physics. Here, by measuring the time-dependent evolution and fluctuation of out-of-time-order correlators, we experimentally investigate the dynamics of quantum… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.08870v1-abstract-full').style.display = 'inline'; document.getElementById('2101.08870v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.08870v1-abstract-full" style="display: none;"> Interaction in quantum systems can spread initially localized quantum information into the many degrees of freedom of the entire system. Understanding this process, known as quantum scrambling, is the key to resolving various conundrums in physics. Here, by measuring the time-dependent evolution and fluctuation of out-of-time-order correlators, we experimentally investigate the dynamics of quantum scrambling on a 53-qubit quantum processor. We engineer quantum circuits that distinguish the two mechanisms associated with quantum scrambling, operator spreading and operator entanglement, and experimentally observe their respective signatures. We show that while operator spreading is captured by an efficient classical model, operator entanglement requires exponentially scaled computational resources to simulate. These results open the path to studying complex and practically relevant physical observables with near-term quantum processors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.08870v1-abstract-full').style.display = 'none'; document.getElementById('2101.08870v1-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> 21 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">Journal ref:</span> Science 374, 1479 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2011.05230">arXiv:2011.05230</a> <span> [<a href="https://arxiv.org/pdf/2011.05230">pdf</a>, <a href="https://arxiv.org/format/2011.05230">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</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/10.1063/5.0037093">10.1063/5.0037093 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Simplified Josephson-junction fabrication process for reproducibly high-performance superconducting qubits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Osman%2C+A">A. Osman</a>, <a href="/search/cond-mat?searchtype=author&query=Simon%2C+J">J. Simon</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">A. Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Kosen%2C+S">S. Kosen</a>, <a href="/search/cond-mat?searchtype=author&query=Krantz%2C+P">P. Krantz</a>, <a href="/search/cond-mat?searchtype=author&query=Perez%2C+D">D. Perez</a>, <a href="/search/cond-mat?searchtype=author&query=Scigliuzzo%2C+M">M. Scigliuzzo</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">Jonas Bylander</a>, <a href="/search/cond-mat?searchtype=author&query=Roudsari%2C+A+F">A. Fadavi Roudsari</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="2011.05230v1-abstract-short" style="display: inline;"> We introduce a simplified fabrication technique for Josephson junctions and demonstrate superconducting Xmon qubits with $T_1$ relaxation times averaging above 50$~渭$s ($Q>$1.5$\times$ 10$^6$). Current shadow-evaporation techniques for aluminum-based Josephson junctions require a separate lithography step to deposit a patch that makes a galvanic, superconducting connection between the junction ele… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2011.05230v1-abstract-full').style.display = 'inline'; document.getElementById('2011.05230v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2011.05230v1-abstract-full" style="display: none;"> We introduce a simplified fabrication technique for Josephson junctions and demonstrate superconducting Xmon qubits with $T_1$ relaxation times averaging above 50$~渭$s ($Q>$1.5$\times$ 10$^6$). Current shadow-evaporation techniques for aluminum-based Josephson junctions require a separate lithography step to deposit a patch that makes a galvanic, superconducting connection between the junction electrodes and the circuit wiring layer. The patch connection eliminates parasitic junctions, which otherwise contribute significantly to dielectric loss. In our patch-integrated cross-type (PICT) junction technique, we use one lithography step and one vacuum cycle to evaporate both the junction electrodes and the patch. In a study of more than 3600 junctions, we show an average resistance variation of 3.7$\%$ on a wafer that contains forty 0.5$\times$0.5-cm$^2$ chips, with junction areas ranging between 0.01 and 0.16 $渭$m$^2$. The average on-chip spread in resistance is 2.7$\%$, with 20 chips varying between 1.4 and 2$\%$. For the junction sizes used for transmon qubits, we deduce a wafer-level transition-frequency variation of 1.7-2.5$\%$. We show that 60-70$\%$ of this variation is attributed to junction-area fluctuations, while the rest is caused by tunnel-junction inhomogeneity. Such high frequency predictability is a requirement for scaling-up the number of qubits in a quantum computer. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2011.05230v1-abstract-full').style.display = 'none'; document.getElementById('2011.05230v1-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 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2020. </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, 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/2003.13522">arXiv:2003.13522</a> <span> [<a href="https://arxiv.org/pdf/2003.13522">pdf</a>, <a href="https://arxiv.org/format/2003.13522">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</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.10.041054">10.1103/PhysRevX.10.041054 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Primary thermometry of propagating microwaves in the quantum regime </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Scigliuzzo%2C+M">Marco Scigliuzzo</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Besse%2C+J">Jean-Claude Besse</a>, <a href="/search/cond-mat?searchtype=author&query=Wallraff%2C+A">Andreas Wallraff</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</a>, <a href="/search/cond-mat?searchtype=author&query=Gasparinetti%2C+S">Simone Gasparinetti</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="2003.13522v1-abstract-short" style="display: inline;"> The ability to control and measure the temperature of propagating microwave modes down to very low temperatures is indispensable for quantum information processing, and may open opportunities for studies of heat transport at the nanoscale, also in the quantum regime. Here we propose and experimentally demonstrate primary thermometry of propagating microwaves using a transmon-type superconducting c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.13522v1-abstract-full').style.display = 'inline'; document.getElementById('2003.13522v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.13522v1-abstract-full" style="display: none;"> The ability to control and measure the temperature of propagating microwave modes down to very low temperatures is indispensable for quantum information processing, and may open opportunities for studies of heat transport at the nanoscale, also in the quantum regime. Here we propose and experimentally demonstrate primary thermometry of propagating microwaves using a transmon-type superconducting circuit. Our device operates continuously, with a sensitivity down to $4\times 10^{-4}$ photons/$\sqrt{\mbox{Hz}}$ and a bandwidth of 40 MHz. We measure the thermal occupation of the modes of a highly attenuated coaxial cable in a range of 0.001 to 0.4 thermal photons, corresponding to a temperature range from 35 mK to 210 mK at a frequency around 5 GHz. To increase the radiation temperature in a controlled fashion, we either inject calibrated, wideband digital noise, or heat the device and its environment. This thermometry scheme can find applications in benchmarking and characterization of cryogenic microwave setups, temperature measurements in hybrid quantum systems, and quantum thermodynamics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.13522v1-abstract-full').style.display = 'none'; document.getElementById('2003.13522v1-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 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. X 10, 041054 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1912.10495">arXiv:1912.10495</a> <span> [<a href="https://arxiv.org/pdf/1912.10495">pdf</a>, <a href="https://arxiv.org/format/1912.10495">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</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/PhysRevApplied.14.034010">10.1103/PhysRevApplied.14.034010 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Improved success probability with greater circuit depth for the quantum approximate optimization algorithm </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Vikst%C3%A5l%2C+P">Pontus Vikst氓l</a>, <a href="/search/cond-mat?searchtype=author&query=Warren%2C+C">Christopher Warren</a>, <a href="/search/cond-mat?searchtype=author&query=Svensson%2C+M">Marika Svensson</a>, <a href="/search/cond-mat?searchtype=author&query=Gu%2C+X">Xiu Gu</a>, <a href="/search/cond-mat?searchtype=author&query=Kockum%2C+A+F">Anton Frisk Kockum</a>, <a href="/search/cond-mat?searchtype=author&query=Krantz%2C+P">Philip Krantz</a>, <a href="/search/cond-mat?searchtype=author&query=Kri%C5%BEan%2C+C">Christian Kri啪an</a>, <a href="/search/cond-mat?searchtype=author&query=Shiri%2C+D">Daryoush Shiri</a>, <a href="/search/cond-mat?searchtype=author&query=Svensson%2C+I">Ida-Maria Svensson</a>, <a href="/search/cond-mat?searchtype=author&query=Tancredi%2C+G">Giovanna Tancredi</a>, <a href="/search/cond-mat?searchtype=author&query=Johansson%2C+G">G枚ran Johansson</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</a>, <a href="/search/cond-mat?searchtype=author&query=Ferrini%2C+G">Giulia Ferrini</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">Jonas Bylander</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="1912.10495v2-abstract-short" style="display: inline;"> Present-day, noisy, small or intermediate-scale quantum processors---although far from fault-tolerant---support the execution of heuristic quantum algorithms, which might enable a quantum advantage, for example, when applied to combinatorial optimization problems. On small-scale quantum processors, validations of such algorithms serve as important technology demonstrators. We implement the quantum… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.10495v2-abstract-full').style.display = 'inline'; document.getElementById('1912.10495v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1912.10495v2-abstract-full" style="display: none;"> Present-day, noisy, small or intermediate-scale quantum processors---although far from fault-tolerant---support the execution of heuristic quantum algorithms, which might enable a quantum advantage, for example, when applied to combinatorial optimization problems. On small-scale quantum processors, validations of such algorithms serve as important technology demonstrators. We implement the quantum approximate optimization algorithm (QAOA) on our hardware platform, consisting of two superconducting transmon qubits and one parametrically modulated coupler. We solve small instances of the NP-complete exact-cover problem, with 96.6% success probability, by iterating the algorithm up to level two. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.10495v2-abstract-full').style.display = 'none'; document.getElementById('1912.10495v2-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> 15 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 December, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2019. </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, 7 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Applied 14, 034010 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1912.09119">arXiv:1912.09119</a> <span> [<a href="https://arxiv.org/pdf/1912.09119">pdf</a>, <a href="https://arxiv.org/format/1912.09119">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</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/10.1088/1367-2630/ab8044">10.1088/1367-2630/ab8044 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Phononic loss in superconducting resonators on piezoelectric substrates </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Scigliuzzo%2C+M">Marco Scigliuzzo</a>, <a href="/search/cond-mat?searchtype=author&query=Bruhat%2C+L+E">Laure E. Bruhat</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Burnett%2C+J+J">Jonathan J. Burnett</a>, <a href="/search/cond-mat?searchtype=author&query=Roudsari%2C+A+F">Anita Fadavi Roudsari</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</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="1912.09119v1-abstract-short" style="display: inline;"> We numerically and experimentally investigate the phononic loss for superconducting resonators fabricated on a piezoelectric substrate. With the help of finite element method simulations, we calculate the energy loss due to electromechanical conversion into bulk and surface acoustic waves. This sets an upper limit for the resonator internal quality factor $Q_i$. To validate the simulation, we fabr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.09119v1-abstract-full').style.display = 'inline'; document.getElementById('1912.09119v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1912.09119v1-abstract-full" style="display: none;"> We numerically and experimentally investigate the phononic loss for superconducting resonators fabricated on a piezoelectric substrate. With the help of finite element method simulations, we calculate the energy loss due to electromechanical conversion into bulk and surface acoustic waves. This sets an upper limit for the resonator internal quality factor $Q_i$. To validate the simulation, we fabricate quarter wavelength coplanar waveguide resonators on GaAs and measure $Q_i$ as function of frequency, power and temperature. We observe a linear increase of $Q_i$ with frequency, as predicted by the simulations for a constant electromechanical coupling. Additionally, $Q_i$ shows a weak power dependence and a negligible temperature dependence around 10$\,$mK, excluding two level systems and non-equilibrium quasiparticles as the main source of losses at that temperature. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.09119v1-abstract-full').style.display = 'none'; document.getElementById('1912.09119v1-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 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/1912.02124">arXiv:1912.02124</a> <span> [<a href="https://arxiv.org/pdf/1912.02124">pdf</a>, <a href="https://arxiv.org/format/1912.02124">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</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/s41534-021-00367-5">10.1038/s41534-021-00367-5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Characterizing decoherence rates of a superconducting qubit by direct microwave scattering </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lu%2C+Y">Yong Lu</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Burnett%2C+J+J">Jonathan J. Burnett</a>, <a href="/search/cond-mat?searchtype=author&query=Wiegand%2C+E">Emely Wiegand</a>, <a href="/search/cond-mat?searchtype=author&query=Suri%2C+B">Baladitya Suri</a>, <a href="/search/cond-mat?searchtype=author&query=Krantz%2C+P">Philip Krantz</a>, <a href="/search/cond-mat?searchtype=author&query=Roudsari%2C+A+F">Anita Fadavi Roudsari</a>, <a href="/search/cond-mat?searchtype=author&query=Kockum%2C+A+F">Anton Frisk Kockum</a>, <a href="/search/cond-mat?searchtype=author&query=Gasparinetti%2C+S">Simone Gasparinetti</a>, <a href="/search/cond-mat?searchtype=author&query=Johansson%2C+G">G枚ran Johansson</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</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="1912.02124v1-abstract-short" style="display: inline;"> We experimentally investigate a superconducting qubit coupled to the end of an open transmission line, in a regime where the qubit decay rates to the transmission line and to its own environment are comparable. We perform measurements of coherent and incoherent scattering, on- and off-resonant fluorescence, and time-resolved dynamics to determine the decay and decoherence rates of the qubit. In pa… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.02124v1-abstract-full').style.display = 'inline'; document.getElementById('1912.02124v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1912.02124v1-abstract-full" style="display: none;"> We experimentally investigate a superconducting qubit coupled to the end of an open transmission line, in a regime where the qubit decay rates to the transmission line and to its own environment are comparable. We perform measurements of coherent and incoherent scattering, on- and off-resonant fluorescence, and time-resolved dynamics to determine the decay and decoherence rates of the qubit. In particular, these measurements let us discriminate between non-radiative decay and pure dephasing. We combine and contrast results across all methods and find consistent values for the extracted rates. The results show that the pure dephasing rate is one order of magnitude smaller than the non-radiative decay rate for our qubit. Our results indicate a pathway to benchmark decoherence rates of superconducting qubits in a resonator-free setting. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.02124v1-abstract-full').style.display = 'none'; document.getElementById('1912.02124v1-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> 4 December, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2019. </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">13 pages, 6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> npj Quantum Information 7, 35 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1901.04417">arXiv:1901.04417</a> <span> [<a href="https://arxiv.org/pdf/1901.04417">pdf</a>, <a href="https://arxiv.org/format/1901.04417">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</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/10.1038/s41534-019-0168-5">10.1038/s41534-019-0168-5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Decoherence benchmarking of superconducting qubits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Burnett%2C+J">Jonathan Burnett</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Scigliuzzo%2C+M">Marco Scigliuzzo</a>, <a href="/search/cond-mat?searchtype=author&query=Niepce%2C+D">David Niepce</a>, <a href="/search/cond-mat?searchtype=author&query=Kudra%2C+M">Marina Kudra</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">Jonas Bylander</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="1901.04417v2-abstract-short" style="display: inline;"> We benchmark the decoherence of superconducting qubits to examine the temporal stability of energy-relaxation and dephasing. By collecting statistics during measurements spanning multiple days, we find the mean parameters $\overline{T_{1}}$ = 49 $渭$s and $\overline{T_{2}^{*}}$ = 95 $渭$s, however, both of these quantities fluctuate explaining the need for frequent re-calibration in qubit setups. Ou… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.04417v2-abstract-full').style.display = 'inline'; document.getElementById('1901.04417v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1901.04417v2-abstract-full" style="display: none;"> We benchmark the decoherence of superconducting qubits to examine the temporal stability of energy-relaxation and dephasing. By collecting statistics during measurements spanning multiple days, we find the mean parameters $\overline{T_{1}}$ = 49 $渭$s and $\overline{T_{2}^{*}}$ = 95 $渭$s, however, both of these quantities fluctuate explaining the need for frequent re-calibration in qubit setups. Our main finding is that fluctuations in qubit relaxation are local to the qubit and are caused by instabilities of near-resonant two-level-systems (TLS). Through statistical analysis, we determine switching rates of these TLS and observe the coherent coupling between an individual TLS and a transmon qubit. Finally, we find evidence that the qubit's frequency stability is limited by capacitance noise. Importantly, this produces a 0.8 ms limit on the pure dephasing which we also observe. Collectively, these findings raise the need for performing qubit metrology to examine the reproducibility of qubit parameters, where these fluctuations could affect qubit gate fidelity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.04417v2-abstract-full').style.display = 'none'; document.getElementById('1901.04417v2-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 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 January, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2019. </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">15 pages ArXiv version rev2</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> npj Quantum Informationvolume 5, Article number: 9 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1802.09259">arXiv:1802.09259</a> <span> [<a href="https://arxiv.org/pdf/1802.09259">pdf</a>, <a href="https://arxiv.org/format/1802.09259">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</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/10.1063/1.5026974">10.1063/1.5026974 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Period multiplication in a parametrically driven superconducting resonator </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Svensson%2C+I">Ida-Maria Svensson</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">Jonas Bylander</a>, <a href="/search/cond-mat?searchtype=author&query=Shumeiko%2C+V">Vitaly Shumeiko</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</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="1802.09259v1-abstract-short" style="display: inline;"> We report on the experimental observation of period multiplication in parametrically driven tunable superconducting resonators. We modulate the magnetic flux through a superconducting quantum interference device, attached to a quarter-wavelength resonator, with frequencies $n蠅$ close to multiples, $n=2,\,3,\,4,\,5$, of the resonator fundamental mode and observe intense output radiation at $蠅$. The… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1802.09259v1-abstract-full').style.display = 'inline'; document.getElementById('1802.09259v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1802.09259v1-abstract-full" style="display: none;"> We report on the experimental observation of period multiplication in parametrically driven tunable superconducting resonators. We modulate the magnetic flux through a superconducting quantum interference device, attached to a quarter-wavelength resonator, with frequencies $n蠅$ close to multiples, $n=2,\,3,\,4,\,5$, of the resonator fundamental mode and observe intense output radiation at $蠅$. The output field manifests $n$-fold degeneracy with respect to the phase, the $n$ states are phase shifted by $2蟺/n$ with respect to each other. Our demonstration verifies the theoretical prediction by Guo et al. in PRL 111, 205303 (2013), and paves the way for engineering complex macroscopic quantum cat states with microwave photons. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1802.09259v1-abstract-full').style.display = 'none'; document.getElementById('1802.09259v1-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 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">Journal ref:</span> Appl. Phys. Lett. 113, 022602 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1801.10204">arXiv:1801.10204</a> <span> [<a href="https://arxiv.org/pdf/1801.10204">pdf</a>, <a href="https://arxiv.org/format/1801.10204">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</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/10.1088/1742-6596/969/1/012131">10.1088/1742-6596/969/1/012131 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Noise and loss of superconducting aluminium resonators at single photon energies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Burnett%2C+J">Jonathan Burnett</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Niepce%2C+D">David Niepce</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">Jonas Bylander</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="1801.10204v1-abstract-short" style="display: inline;"> The loss and noise mechanisms of superconducting resonators are useful tools for understanding decoherence in superconducting circuits. While the loss mechanisms have been heavily studied, noise in superconducting resonators has only recently been investigated. In particular, there is an absence of literature on noise in the single photon limit. Here, we measure the loss and noise of an aluminium… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.10204v1-abstract-full').style.display = 'inline'; document.getElementById('1801.10204v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1801.10204v1-abstract-full" style="display: none;"> The loss and noise mechanisms of superconducting resonators are useful tools for understanding decoherence in superconducting circuits. While the loss mechanisms have been heavily studied, noise in superconducting resonators has only recently been investigated. In particular, there is an absence of literature on noise in the single photon limit. Here, we measure the loss and noise of an aluminium on silicon quarter-wavelength ($位/4$) resonator in the single photon regime. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.10204v1-abstract-full').style.display = 'none'; document.getElementById('1801.10204v1-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 January, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">LT28 Conference proceeding, to be published in IOP 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/1801.04566">arXiv:1801.04566</a> <span> [<a href="https://arxiv.org/pdf/1801.04566">pdf</a>, <a href="https://arxiv.org/format/1801.04566">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="Superconductivity">cond-mat.supr-con</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/PhysRevB.97.144502">10.1103/PhysRevB.97.144502 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Nondegenerate parametric oscillations in a tunable superconducting resonator </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Krantz%2C+P">Philip Krantz</a>, <a href="/search/cond-mat?searchtype=author&query=Simoen%2C+M">Micha毛l Simoen</a>, <a href="/search/cond-mat?searchtype=author&query=Svensson%2C+I">Ida-Maria Svensson</a>, <a href="/search/cond-mat?searchtype=author&query=Schneider%2C+B">Ben Schneider</a>, <a href="/search/cond-mat?searchtype=author&query=Shumeiko%2C+V">Vitaly Shumeiko</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">Jonas Bylander</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="1801.04566v1-abstract-short" style="display: inline;"> We investigate nondegenerate parametric oscillations in a multimode superconducting microwave resonator that is terminated by a SQUID. The parametric effect is achieved by modulating magnetic flux through the SQUID at a frequency close to the sum of two resonator-mode frequencies. For modulation amplitudes exceeding an instability threshold, self-sustained oscillations are observed in both modes.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.04566v1-abstract-full').style.display = 'inline'; document.getElementById('1801.04566v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1801.04566v1-abstract-full" style="display: none;"> We investigate nondegenerate parametric oscillations in a multimode superconducting microwave resonator that is terminated by a SQUID. The parametric effect is achieved by modulating magnetic flux through the SQUID at a frequency close to the sum of two resonator-mode frequencies. For modulation amplitudes exceeding an instability threshold, self-sustained oscillations are observed in both modes. The amplitudes of these oscillations show good quantitative agreement with a theoretical model. The oscillation phases are found to be correlated and exhibit strong fluctuations which broaden the oscillation spectral linewidths. These linewidths are significantly reduced by applying a weak on-resonance tone, which also suppresses the phase fluctuations. When the weak tone is detuned, we observe synchronization of the oscillation frequency with the frequency of the input. For the detuned input, we also observe an emergence of three idlers in the output. This observation is in agreement with theory indicating four-mode amplification and squeezing of a coherent input. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.04566v1-abstract-full').style.display = 'none'; document.getElementById('1801.04566v1-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 January, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">7 pages, 8 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 97, 144502 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1712.05370">arXiv:1712.05370</a> <span> [<a href="https://arxiv.org/pdf/1712.05370">pdf</a>, <a href="https://arxiv.org/format/1712.05370">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Stabilizing a high-pressure phase in InSb at ambient conditions with a laser-driven pressure pulse </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Jarnac%2C+A">A. Jarnac</a>, <a href="/search/cond-mat?searchtype=author&query=Wang%2C+X">Xiaocui Wang</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A+U+J">A. U. J Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Burza%2C+M">M. Burza</a>, <a href="/search/cond-mat?searchtype=author&query=Ekstrom%2C+J+C">J. C. Ekstrom</a>, <a href="/search/cond-mat?searchtype=author&query=Enquist%2C+H">H. Enquist</a>, <a href="/search/cond-mat?searchtype=author&query=Jurgilaitis%2C+A">A. Jurgilaitis</a>, <a href="/search/cond-mat?searchtype=author&query=Kretzschmar%2C+N">N. Kretzschmar</a>, <a href="/search/cond-mat?searchtype=author&query=Persson%2C+A+I+H">A. I. H. Persson</a>, <a href="/search/cond-mat?searchtype=author&query=Tu%2C+C+M">C. M. Tu</a>, <a href="/search/cond-mat?searchtype=author&query=Wulff%2C+M">M. Wulff</a>, <a href="/search/cond-mat?searchtype=author&query=Dorchies%2C+F">F. Dorchies</a>, <a href="/search/cond-mat?searchtype=author&query=Larsson%2C+J">J. Larsson</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="1712.05370v1-abstract-short" style="display: inline;"> In this letter, we describe the stabilization of indium antimonide (InSb) in the high-pressure orthorhombic phase (InSb-III) at ambient conditions. Until now, InSb-III has only been observed above 9 GPa, or at around 3 GPa as a metastable structure during the phase transition from cubic zinc blende (InSb-I) to orthorhombic InSb-IV. The crystalline phase transition from InSb-I to InSb-III was drive… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1712.05370v1-abstract-full').style.display = 'inline'; document.getElementById('1712.05370v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1712.05370v1-abstract-full" style="display: none;"> In this letter, we describe the stabilization of indium antimonide (InSb) in the high-pressure orthorhombic phase (InSb-III) at ambient conditions. Until now, InSb-III has only been observed above 9 GPa, or at around 3 GPa as a metastable structure during the phase transition from cubic zinc blende (InSb-I) to orthorhombic InSb-IV. The crystalline phase transition from InSb-I to InSb-III was driven by an ultrashort, laser-generated, non-hydrostatic pressure pulse. The transition occurred in preferred orientations locked to the initial orientation of the InSb-I crystal, breaking the symmetry of the InSb-I cubic cell to form the InSb-III orthorhombic cell. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1712.05370v1-abstract-full').style.display = 'none'; document.getElementById('1712.05370v1-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, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2017. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1707.04093">arXiv:1707.04093</a> <span> [<a href="https://arxiv.org/pdf/1707.04093">pdf</a>, <a href="https://arxiv.org/format/1707.04093">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</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/PhysRevB.96.174503">10.1103/PhysRevB.96.174503 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Period-tripling subharmonic oscillations in a driven superconducting resonator </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Svensson%2C+I">Ida-Maria Svensson</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Krantz%2C+P">Philip Krantz</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">Jonas Bylander</a>, <a href="/search/cond-mat?searchtype=author&query=Shumeiko%2C+V">Vitaly Shumeiko</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</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="1707.04093v3-abstract-short" style="display: inline;"> We have observed period-tripling subharmonic oscillations, in a superconducting coplanar waveguide resonator operated in the quantum regime, $k_B T \ll \hbar蠅$. The resonator is terminated by a tunable inductance that provides a Kerr-type nonlinearity. We detected the output field quadratures at frequencies near the fundamental mode, $蠅/2蟺\sim 5\,$GHz, when the resonator was driven by a current at… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.04093v3-abstract-full').style.display = 'inline'; document.getElementById('1707.04093v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1707.04093v3-abstract-full" style="display: none;"> We have observed period-tripling subharmonic oscillations, in a superconducting coplanar waveguide resonator operated in the quantum regime, $k_B T \ll \hbar蠅$. The resonator is terminated by a tunable inductance that provides a Kerr-type nonlinearity. We detected the output field quadratures at frequencies near the fundamental mode, $蠅/2蟺\sim 5\,$GHz, when the resonator was driven by a current at $3蠅$ with an amplitude exceeding an instability threshold. The output radiation was red-detuned from the fundamental mode. We observed three stable radiative states with equal amplitudes and phase-shifted by $120^\circ$. The downconversion from $3蠅$ to $蠅$ is strongly enhanced by resonant excitation of the second mode of the resonator, and the cross-Kerr effect. Our experimental results are in quantitative agreement with a model for the driven dynamics of two coupled modes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1707.04093v3-abstract-full').style.display = 'none'; document.getElementById('1707.04093v3-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 November, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 July, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 96, 174503 (2017) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1706.06821">arXiv:1706.06821</a> <span> [<a href="https://arxiv.org/pdf/1706.06821">pdf</a>, <a href="https://arxiv.org/format/1706.06821">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</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/10.1088/1742-6596/969/1/012146">10.1088/1742-6596/969/1/012146 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Microwave photon generation in a doubly tunable superconducting resonator </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Svensson%2C+I">Ida-Maria Svensson</a>, <a href="/search/cond-mat?searchtype=author&query=Pierre%2C+M">Mathieu Pierre</a>, <a href="/search/cond-mat?searchtype=author&query=Simoen%2C+M">Micha毛l Simoen</a>, <a href="/search/cond-mat?searchtype=author&query=Wustmann%2C+W">Waltraut Wustmann</a>, <a href="/search/cond-mat?searchtype=author&query=Krantz%2C+P">Philip Krantz</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Johansson%2C+G">G枚ran Johansson</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">Jonas Bylander</a>, <a href="/search/cond-mat?searchtype=author&query=Shumeiko%2C+V">Vitaly Shumeiko</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</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="1706.06821v1-abstract-short" style="display: inline;"> We have developed and tested a doubly tunable resonator, with the intention to simulate fast motion of the resonator boundaries in real space. Our device is a superconducting coplanar-waveguide half-wavelength microwave resonator, with fundamental resonant frequency ~5 GHz. Both of its ends are terminated by dc-SQUIDs, which serve as magnetic-flux-controlled inductances. Applying a flux to either… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1706.06821v1-abstract-full').style.display = 'inline'; document.getElementById('1706.06821v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1706.06821v1-abstract-full" style="display: none;"> We have developed and tested a doubly tunable resonator, with the intention to simulate fast motion of the resonator boundaries in real space. Our device is a superconducting coplanar-waveguide half-wavelength microwave resonator, with fundamental resonant frequency ~5 GHz. Both of its ends are terminated by dc-SQUIDs, which serve as magnetic-flux-controlled inductances. Applying a flux to either SQUID allows tuning of the resonant frequency by approximately 700 MHz. By using two separate on-chip magnetic-flux lines, we modulate the SQUIDs with two tones of equal frequency, close to twice that of the resonator's fundamental mode. We observe photon generation, at the fundamental frequency, above a certain pump amplitude threshold. By varying the relative phase of the two pumps we are able to control the photon generation threshold, in good agreement with a theoretical model for the modulation of the boundary conditions. At the same time, some of our observations deviate from the theoretical predictions, which we attribute to parasitic couplings, resulting in current driving of the SQUIDs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1706.06821v1-abstract-full').style.display = 'none'; document.getElementById('1706.06821v1-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> 21 June, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 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">7 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Journal of Physics: Conference Series 969, 012146 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1508.02886">arXiv:1508.02886</a> <span> [<a href="https://arxiv.org/pdf/1508.02886">pdf</a>, <a href="https://arxiv.org/format/1508.02886">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</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/ncomms11417">10.1038/ncomms11417 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Single-shot Readout of a Superconducting Qubit using a Josephson Parametric Oscillator </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Krantz%2C+P">Philip Krantz</a>, <a href="/search/cond-mat?searchtype=author&query=Bengtsson%2C+A">Andreas Bengtsson</a>, <a href="/search/cond-mat?searchtype=author&query=Simoen%2C+M">Micha毛l Simoen</a>, <a href="/search/cond-mat?searchtype=author&query=Gustavsson%2C+S">Simon Gustavsson</a>, <a href="/search/cond-mat?searchtype=author&query=Shumeiko%2C+V">Vitaly Shumeiko</a>, <a href="/search/cond-mat?searchtype=author&query=Oliver%2C+W+D">W. D. Oliver</a>, <a href="/search/cond-mat?searchtype=author&query=Wilson%2C+C+M">C. M. Wilson</a>, <a href="/search/cond-mat?searchtype=author&query=Delsing%2C+P">Per Delsing</a>, <a href="/search/cond-mat?searchtype=author&query=Bylander%2C+J">Jonas Bylander</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="1508.02886v2-abstract-short" style="display: inline;"> We propose and demonstrate a new read-out technique for a superconducting qubit by dispersively coupling it to a Josephson parametric oscillator. We employ a tunable quarter-wavelength superconducting resonator and modulate its resonant frequency at twice its value with an amplitude surpassing the threshold for parametric instability. We map the qubit states onto two distinct states of classical p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1508.02886v2-abstract-full').style.display = 'inline'; document.getElementById('1508.02886v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1508.02886v2-abstract-full" style="display: none;"> We propose and demonstrate a new read-out technique for a superconducting qubit by dispersively coupling it to a Josephson parametric oscillator. We employ a tunable quarter-wavelength superconducting resonator and modulate its resonant frequency at twice its value with an amplitude surpassing the threshold for parametric instability. We map the qubit states onto two distinct states of classical parametric oscillation: one oscillating state, with $185\pm15$ photons in the resonator, and one with zero oscillation amplitude. This high contrast obviates a following quantum-limited amplifier. We demonstrate proof-of-principle, single-shot readout performance, and present an error budget indicating that this method can surpass the fidelity threshold required for quantum computing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1508.02886v2-abstract-full').style.display = 'none'; document.getElementById('1508.02886v2-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 February, 2016; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 August, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">11 pages, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Communications 7, 11417 (2016) </p> </li> </ol> <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> <li><a href="https://info.arxiv.org/help">Help</a></li> </ul> </div> <div class="column"> <ul class="nav-spaced"> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>contact arXiv</title><desc>Click here to contact arXiv</desc><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 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