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<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/2502.05572">arXiv:2502.05572</a> <span> [<a href="https://arxiv.org/pdf/2502.05572">pdf</a>, <a href="https://arxiv.org/format/2502.05572">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="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.134.053801">10.1103/PhysRevLett.134.053801 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Postselection-Free Cavity-Enhanced Narrow-Band Orbital Angular Momentum Entangled Photon Source </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wan%2C+P">Pei Wan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+W">Wen-Zheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Lou%2C+Y">Yan-Chao Lou</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+H">Han Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</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="2502.05572v1-abstract-short" style="display: inline;"> Cavity-enhanced spontaneous parametric down-conversion (SPDC) provides a significant way to produce $\sim$10 MHz narrow-band photon pairs, which matches the bandwidth of photon for quantum memory. However, the output photon pairs from the cavity is not entangled and the postselection is required to create the entanglement outside the cavity, so the direct output of cavity-enhanced narrow-band enta… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.05572v1-abstract-full').style.display = 'inline'; document.getElementById('2502.05572v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2502.05572v1-abstract-full" style="display: none;"> Cavity-enhanced spontaneous parametric down-conversion (SPDC) provides a significant way to produce $\sim$10 MHz narrow-band photon pairs, which matches the bandwidth of photon for quantum memory. However, the output photon pairs from the cavity is not entangled and the postselection is required to create the entanglement outside the cavity, so the direct output of cavity-enhanced narrow-band entangled photon pairs is still an open challenge. Here we propose a solution that realizes the first postselection-free cavity-enhanced narrow-band entangled photon pairs. The entanglement is achieved in degree of freedom (DOF) of orbital angular momentum (OAM) by implementing an OAM-conservation SPDC process in an actively and precisely controlled cavity supporting degenerate high-order OAM modes. The measured linewidth for the two photons is 13.8 MHz and the measured fidelity is 0.969(3) for the directly generated OAM entangled two photons. We deterministically transfer the OAM entanglement to polarization one with almost no loss and obtain polarization entangled two photons with a fidelity of 0.948(2). Moreover, we produce narrow-band OAM-polarization hyperentangled photon pairs with a fidelity of 0.850(2) by establishing polarization entanglement with preservation of OAM entanglement, which is realized by interfering the two photons on a polarizing beam splitter (PBS) and post-selecting the events of one and only one photon in on each of the PBS port. Novel cavity may find applications in cavity-based light-matter interaction. Our results provide an efficient and promising approach to create narrow-band entangled photon sources for memory-based long-distance quantum communication and network. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.05572v1-abstract-full').style.display = 'none'; document.getElementById('2502.05572v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 5 figures,</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 134, 053801 (2025) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2502.01480">arXiv:2502.01480</a> <span> [<a href="https://arxiv.org/pdf/2502.01480">pdf</a>, <a href="https://arxiv.org/format/2502.01480">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> </div> </div> <p class="title is-5 mathjax"> Two-particle quantum interference in a nonlinear optical medium: a witness of timelike indistinguishability </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Chen%2C+C">Chao Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Xue%2C+S">Shu-Tian Xue</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+Y">Yu-Peng Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jing Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Wan%2C+P">Pei Wan</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Jabbour%2C+M+G">Michael G. Jabbour</a>, <a href="/search/quant-ph?searchtype=author&query=Cerf%2C+N+J">Nicolas J. Cerf</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</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="2502.01480v1-abstract-short" style="display: inline;"> The Hong-Ou-Mandel effect is a paradigmatic quantum phenomenon demonstrating the interference of two indistinguishable photons that are linearly coupled at a 50:50 beam splitter. Here, we transpose such a two-particle quantum interference effect to the nonlinear regime, when two single photons are impinging on a parametric down-conversion crystal. Formally, this transposition amounts to exchanging… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.01480v1-abstract-full').style.display = 'inline'; document.getElementById('2502.01480v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2502.01480v1-abstract-full" style="display: none;"> The Hong-Ou-Mandel effect is a paradigmatic quantum phenomenon demonstrating the interference of two indistinguishable photons that are linearly coupled at a 50:50 beam splitter. Here, we transpose such a two-particle quantum interference effect to the nonlinear regime, when two single photons are impinging on a parametric down-conversion crystal. Formally, this transposition amounts to exchanging space and time variables, giving rise to an unknown form of timelike quantum interference. The two-photon component of the output state is a superposition of the incident photons being either transmitted or reborn, that is, replaced by indistinguishable substitutes due to their interaction with the nonlinear crystal. We experimentally demonstrate the suppression of the probability of detecting precisely one photon pair when the amplification gain is tuned to 2, which arises from the destructive interference between the transmitted and reborn photon pairs. This heretofore unobserved quantum manifestation of indistinguishability in time pushes nonlinear quantum interference towards a new regime with multiple photons. Hence, composing this effect with larger linear optical circuits should provide a tool to generate multimode quantum non-Gaussian states, which are essential resources for photonic quantum computers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.01480v1-abstract-full').style.display = 'none'; document.getElementById('2502.01480v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2025. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.04414">arXiv:2412.04414</a> <span> [<a href="https://arxiv.org/pdf/2412.04414">pdf</a>, <a href="https://arxiv.org/format/2412.04414">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> </div> </div> <p class="title is-5 mathjax"> Emergent unitary designs for encoded qubits from coherent errors and syndrome measurements </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zihan Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+E">Eric Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Khemani%2C+V">Vedika Khemani</a>, <a href="/search/quant-ph?searchtype=author&query=Gullans%2C+M+J">Michael J. Gullans</a>, <a href="/search/quant-ph?searchtype=author&query=Ippoliti%2C+M">Matteo Ippoliti</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="2412.04414v1-abstract-short" style="display: inline;"> Unitary $k$-designs are distributions of unitary gates that match the Haar distribution up to its $k$-th statistical moment. They are a crucial resource for randomized quantum protocols. However, their implementation on encoded logical qubits is nontrivial due to the need for magic gates, which can require a large resource overhead. In this work, we propose an efficient approach to generate unitar… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.04414v1-abstract-full').style.display = 'inline'; document.getElementById('2412.04414v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.04414v1-abstract-full" style="display: none;"> Unitary $k$-designs are distributions of unitary gates that match the Haar distribution up to its $k$-th statistical moment. They are a crucial resource for randomized quantum protocols. However, their implementation on encoded logical qubits is nontrivial due to the need for magic gates, which can require a large resource overhead. In this work, we propose an efficient approach to generate unitary designs for encoded qubits in surface codes by applying local unitary rotations ("coherent errors") on the physical qubits followed by syndrome measurement and error correction. We prove that under some conditions on the coherent errors (notably including all single-qubit unitaries) and on the error correcting code, this process induces a unitary transformation of the logical subspace. We numerically show that the ensemble of logical unitaries (indexed by the random syndrome outcomes) converges to a unitary design in the thermodynamic limit, provided the density or strength of coherent errors is above a finite threshold. This "unitary design" phase transition coincides with the code's coherent error threshold under optimal decoding. Furthermore, we propose a classical algorithm to simulate the protocol based on a "staircase" implementation of the surface code encoder and decoder circuits. This enables a mapping to a 1+1D monitored circuit, where we observe an entanglement phase transition (and thus a classical complexity phase transition of the decoding algorithm) coinciding with the aforementioned unitary design phase transition. Our results provide a practical way to realize unitary designs on encoded qubits, with applications including quantum state tomography and benchmarking in error correcting codes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.04414v1-abstract-full').style.display = 'none'; document.getElementById('2412.04414v1-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 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">15+3 pages, 8+2 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/2410.15389">arXiv:2410.15389</a> <span> [<a href="https://arxiv.org/pdf/2410.15389">pdf</a>, <a href="https://arxiv.org/format/2410.15389">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> </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/sciadv.adr9527">10.1126/sciadv.adr9527 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of quantum superposition of topological defects in a trapped ion quantum simulator </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zhijie Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yukai Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shijiao Li</a>, <a href="/search/quant-ph?searchtype=author&query=Mei%2C+Q">Quanxin Mei</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+B">Bowen Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+G">Gangxi Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+Y">Yue Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Qi%2C+B">Binxiang Qi</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Z">Zichao Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Hou%2C+P">Panyu Hou</a>, <a href="/search/quant-ph?searchtype=author&query=Duan%2C+L">Luming Duan</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="2410.15389v1-abstract-short" style="display: inline;"> Topological defects are discontinuities of a system protected by global properties, with wide applications in mathematics and physics. While previous experimental studies mostly focused on their classical properties, it has been predicted that topological defects can exhibit quantum superposition. Despite the fundamental interest and potential applications in understanding symmetry-breaking dynami… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15389v1-abstract-full').style.display = 'inline'; document.getElementById('2410.15389v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.15389v1-abstract-full" style="display: none;"> Topological defects are discontinuities of a system protected by global properties, with wide applications in mathematics and physics. While previous experimental studies mostly focused on their classical properties, it has been predicted that topological defects can exhibit quantum superposition. Despite the fundamental interest and potential applications in understanding symmetry-breaking dynamics of quantum phase transitions, its experimental realization still remains a challenge. Here, we report the observation of quantum superposition of topological defects in a trapped-ion quantum simulator. By engineering long-range spin-spin interactions, we observe a spin kink splitting into a superposition of kinks at different positions, creating a ``Schrodinger kink'' that manifests non-locality and quantum interference. Furthermore, by preparing superposition states of neighboring kinks with different phases, we observe the propagation of the wave packet in different directions, thus unambiguously verifying the quantum coherence in the superposition states. Our work provides useful tools for non-equilibrium dynamics in quantum Kibble-Zurek physics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15389v1-abstract-full').style.display = 'none'; document.getElementById('2410.15389v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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, already published in Science Advances</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Sci. Adv.10,eadr9527(2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.02758">arXiv:2410.02758</a> <span> [<a href="https://arxiv.org/pdf/2410.02758">pdf</a>, <a href="https://arxiv.org/format/2410.02758">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> <p class="title is-5 mathjax"> Pseudoentanglement from tensor networks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zihan Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Feng%2C+X">Xiaozhou Feng</a>, <a href="/search/quant-ph?searchtype=author&query=Ippoliti%2C+M">Matteo Ippoliti</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="2410.02758v2-abstract-short" style="display: inline;"> Pseudoentangled states are defined by their ability to hide their entanglement structure: they are indistinguishable from random states to any observer with polynomial resources, yet can have much less entanglement than random states. Existing constructions of pseudoentanglement based on phase- and/or subset-states are limited in the entanglement structures they can hide: e.g., the states may have… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.02758v2-abstract-full').style.display = 'inline'; document.getElementById('2410.02758v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.02758v2-abstract-full" style="display: none;"> Pseudoentangled states are defined by their ability to hide their entanglement structure: they are indistinguishable from random states to any observer with polynomial resources, yet can have much less entanglement than random states. Existing constructions of pseudoentanglement based on phase- and/or subset-states are limited in the entanglement structures they can hide: e.g., the states may have low entanglement on a single cut, on all cuts at once, or on local cuts in one dimension. Here we introduce new constructions of pseudoentangled states based on (pseudo)random tensor networks that affords much more flexibility in the achievable entanglement structures. We illustrate our construction with the simplest example of a matrix product state, realizable as a staircase circuit of pseudorandom unitary gates, which exhibits pseudo-area-law scaling of entanglement in one dimension. We then generalize our construction to arbitrary tensor network structures that admit an isometric realization. A notable application of this result is the construction of pseudoentangled `holographic' states whose entanglement entropy obeys a Ryu-Takayanagi `minimum-cut' formula, answering a question posed in [Aaronson et al., arXiv:2211.00747]. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.02758v2-abstract-full').style.display = 'none'; document.getElementById('2410.02758v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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">5+6 pages, 3 figures. v2: fixed typos and minor issues</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.19043">arXiv:2409.19043</a> <span> [<a href="https://arxiv.org/pdf/2409.19043">pdf</a>, <a href="https://arxiv.org/format/2409.19043">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> </div> </div> <p class="title is-5 mathjax"> Parallel Quantum Signal Processing Via Polynomial Factorization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Martyn%2C+J+M">John M. Martyn</a>, <a href="/search/quant-ph?searchtype=author&query=Rossi%2C+Z+M">Zane M. Rossi</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+K+Z">Kevin Z. Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yuan Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Chuang%2C+I+L">Isaac L. Chuang</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="2409.19043v1-abstract-short" style="display: inline;"> Quantum signal processing (QSP) is a methodology for constructing polynomial transformations of a linear operator encoded in a unitary. Applied to an encoding of a state $蟻$, QSP enables the evaluation of nonlinear functions of the form $\text{tr}(P(蟻))$ for a polynomial $P(x)$, which encompasses relevant properties like entropies and fidelity. However, QSP is a sequential algorithm: implementing… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.19043v1-abstract-full').style.display = 'inline'; document.getElementById('2409.19043v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.19043v1-abstract-full" style="display: none;"> Quantum signal processing (QSP) is a methodology for constructing polynomial transformations of a linear operator encoded in a unitary. Applied to an encoding of a state $蟻$, QSP enables the evaluation of nonlinear functions of the form $\text{tr}(P(蟻))$ for a polynomial $P(x)$, which encompasses relevant properties like entropies and fidelity. However, QSP is a sequential algorithm: implementing a degree-$d$ polynomial necessitates $d$ queries to the encoding, equating to a query depth $d$. Here, we reduce the depth of these property estimation algorithms by developing Parallel Quantum Signal Processing. Our algorithm parallelizes the computation of $\text{tr} (P(蟻))$ over $k$ systems and reduces the query depth to $d/k$, thus enabling a family of time-space tradeoffs for QSP. This furnishes a property estimation algorithm suitable for distributed quantum computers, and is realized at the expense of increasing the number of measurements by a factor $O( \text{poly}(d) 2^{O(k)} )$. We achieve this result by factorizing $P(x)$ into a product of $k$ smaller polynomials of degree $O(d/k)$, which are each implemented in parallel with QSP, and subsequently multiplied together with a swap test to reconstruct $P(x)$. We characterize the achievable class of polynomials by appealing to the fundamental theorem of algebra, and demonstrate application to canonical problems including entropy estimation and partition function evaluation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.19043v1-abstract-full').style.display = 'none'; document.getElementById('2409.19043v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> MIT-CTP/5780 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.14942">arXiv:2409.14942</a> <span> [<a href="https://arxiv.org/pdf/2409.14942">pdf</a>, <a href="https://arxiv.org/format/2409.14942">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="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Electric imaging and dynamics of photo-charged graphene edge </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Ding%2C+Z">Zhe Ding</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zhousheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+X">Xiaodong Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+W">Weihui Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+J">Jun Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+Y">Yumeng Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zhi Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+Z">Zhiwei Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+K">Kai Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yuxin Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+X">Xing Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+P">Pengfei Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Ya Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+J">Jianhua Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Zeng%2C+H">Hualing Zeng</a>, <a href="/search/quant-ph?searchtype=author&query=Zeng%2C+C">Changgan Zeng</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+G">Guosheng Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+F">Fazhan Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+J">Jiangfeng Du</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="2409.14942v1-abstract-short" style="display: inline;"> The one-dimensional side gate based on graphene edges shows a significant capability of reducing the channel length of field-effect transistors, further increasing the integration density of semiconductor devices. The nano-scale electric field distribution near the edge provides the physical limit of the effective channel length, however, its imaging under ambient conditions still lacks, which is… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.14942v1-abstract-full').style.display = 'inline'; document.getElementById('2409.14942v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.14942v1-abstract-full" style="display: none;"> The one-dimensional side gate based on graphene edges shows a significant capability of reducing the channel length of field-effect transistors, further increasing the integration density of semiconductor devices. The nano-scale electric field distribution near the edge provides the physical limit of the effective channel length, however, its imaging under ambient conditions still lacks, which is a critical aspect for the practical deployment of semiconductor devices. Here, we used scanning nitrogen-vacancy microscopy to investigate the electric field distribution near edges of a single-layer-graphene. Real-space scanning maps of photo-charged floating graphene flakes were acquired with a spatial resolution of $\sim$ 10 nm, and the electric edge effect was quantitatively studied by analyzing the NV spin energy level shifts due to the electric Stark effect. Since the graphene flakes are isolated from external electric sources, we brought out a theory based on photo-thermionic effect to explain the charge transfer from graphene to oxygen-terminated diamond probe with a disordered distribution of charge traps. Real-time tracing of electric fields detected the photo-thermionic emission process and the recombination process of the emitted electrons. This study provides a new perspective for graphene-based one-dimensional gates and opto-electronics with nanoscale real-space imaging, and moreover, offers a novel method to tune the chemical environment of diamond surfaces based on optical charge transfer. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.14942v1-abstract-full').style.display = 'none'; document.getElementById('2409.14942v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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, 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/2407.20511">arXiv:2407.20511</a> <span> [<a href="https://arxiv.org/pdf/2407.20511">pdf</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> <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="Chemical Physics">physics.chem-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Building spin-1/2 antiferromagnetic Heisenberg chains with diaza-nanographenes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fu%2C+X">Xiaoshuai Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+L">Li Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+K">Kun Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Henriques%2C+J+C+G">Jo茫o C. G. Henriques</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yixuan Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Han%2C+X">Xianghe Han</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+H">Hui Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yan Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Palma%2C+C">Carlos-Andres Palma</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zhihai Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+X">Xiao Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+S">Shixuan Du</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+J">Ji Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Fern%C3%A1ndez-Rossier%2C+J">Joaqu铆n Fern谩ndez-Rossier</a>, <a href="/search/quant-ph?searchtype=author&query=Feng%2C+X">Xinliang Feng</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+H">Hong-Jun Gao</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="2407.20511v1-abstract-short" style="display: inline;"> Understanding and engineering the coupling of spins in nanomaterials is of central importance for designing novel devices. Graphene nanostructures with 蟺-magnetism offer a chemically tunable platform to explore quantum magnetic interactions. However, realizing spin chains bearing controlled odd-even effects with suitable nanographene systems is challenging. Here, we demonstrate the successful on-s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.20511v1-abstract-full').style.display = 'inline'; document.getElementById('2407.20511v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.20511v1-abstract-full" style="display: none;"> Understanding and engineering the coupling of spins in nanomaterials is of central importance for designing novel devices. Graphene nanostructures with 蟺-magnetism offer a chemically tunable platform to explore quantum magnetic interactions. However, realizing spin chains bearing controlled odd-even effects with suitable nanographene systems is challenging. Here, we demonstrate the successful on-surface synthesis of spin-1/2 antiferromagnetic Heisenberg chains with parity-dependent magnetization based on antiaromatic diaza-hexa-peri-hexabenzocoronene (diaza-HBC) units. Using distinct synthetic strategies, two types of spin chains with different terminals were synthesized, both exhibiting a robust odd-even effect on the spin coupling along the chain. Combined investigations using scanning tunneling microscopy, non-contact atomic force microscopy, density functional theory calculations, and quantum spin models confirmed the structures of the diaza-HBC chains and revealed their magnetic properties, which has an S = 1/2 spin per unit through electron donation from the diaza-HBC core to the Au(111) substrate. Gapped excitations were observed in even-numbered chains, while enhanced Kondo resonance emerged in odd-numbered units of odd-numbered chains due to the redistribution of the unpaired spin along the chain. Our findings provide an effective strategy to construct nanographene spin chains and unveil the odd-even effect in their magnetic properties, offering potential applications in nanoscale spintronics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.20511v1-abstract-full').style.display = 'none'; document.getElementById('2407.20511v1-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> 29 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.16356">arXiv:2407.16356</a> <span> [<a href="https://arxiv.org/pdf/2407.16356">pdf</a>, <a href="https://arxiv.org/format/2407.16356">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> </div> </div> <p class="title is-5 mathjax"> Heralded High-Dimensional Photon-Photon Quantum Gate </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zhi-Feng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Wan%2C+P">Pei Wan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+W">Wen-Zheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jing Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+Y">Yu-Peng Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Xi%2C+H">Han-Bing Xi</a>, <a href="/search/quant-ph?searchtype=author&query=Huber%2C+M">Marcus Huber</a>, <a href="/search/quant-ph?searchtype=author&query=Friis%2C+N">Nicolai Friis</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+X">Xiaoqin Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</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="2407.16356v1-abstract-short" style="display: inline;"> High-dimensional encoding of quantum information holds the potential to greatly increase the computational power of existing devices by enlarging the accessible state space for fixed register size and by reducing the number of required entangling gates. However, qudit-based quantum computation remains far less developed than conventional qubit-based approaches, in particular for photons, which rep… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.16356v1-abstract-full').style.display = 'inline'; document.getElementById('2407.16356v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.16356v1-abstract-full" style="display: none;"> High-dimensional encoding of quantum information holds the potential to greatly increase the computational power of existing devices by enlarging the accessible state space for fixed register size and by reducing the number of required entangling gates. However, qudit-based quantum computation remains far less developed than conventional qubit-based approaches, in particular for photons, which represent natural multi-level information carriers that play a crucial role in the development of quantum networks. A major obstacle for realizing quantum gates between two individual photons is the restriction of direct interaction between photons in linear media. In particular, essential logic components for quantum operations such as native qudit-qudit entangling gates are still missing for optical quantum information processing. Here we address this challenge by presenting a protocol for realizing an entangling gate -- the controlled phase-flip (CPF) gate -- for two photonic qudits in arbitrary dimension. We experimentally demonstrate this protocol by realizing a four-dimensional qudit-qudit CPF gate, whose decomposition would require at least 13 two-qubit entangling gates. Our photonic qudits are encoded in orbital angular momentum (OAM) and we have developed a new active high-precision phase-locking technology to construct a high-dimensional OAM beam splitter that increases the stability of the CPF gate, resulting in a process fidelity within a range of $ [0.64 \pm 0.01, 0.82 \pm 0.01]$. Our experiment represents a significant advance for high-dimensional optical quantum information processing and has the potential for wider applications beyond optical system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.16356v1-abstract-full').style.display = 'none'; document.getElementById('2407.16356v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 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">14 pages, 7 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.05940">arXiv:2404.05940</a> <span> [<a href="https://arxiv.org/pdf/2404.05940">pdf</a>, <a href="https://arxiv.org/format/2404.05940">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> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.109.042428">10.1103/PhysRevA.109.042428 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Machine-learning-inspired quantum control in many-body dynamics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Mao%2C+M">Meng-Yun Mao</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zheng Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+L">Liangsheng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+N">Ning Wu</a>, <a href="/search/quant-ph?searchtype=author&query=You%2C+W">Wen-Long You</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.05940v1-abstract-short" style="display: inline;"> Achieving precise preparation of quantum many-body states is crucial for the practical implementation of quantum computation and quantum simulation. However, the inherent challenges posed by unavoidable excitations at critical points during quench processes necessitate careful design of control fields. In this work, we introduce a promising and versatile dynamic control neural network tailored to… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.05940v1-abstract-full').style.display = 'inline'; document.getElementById('2404.05940v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.05940v1-abstract-full" style="display: none;"> Achieving precise preparation of quantum many-body states is crucial for the practical implementation of quantum computation and quantum simulation. However, the inherent challenges posed by unavoidable excitations at critical points during quench processes necessitate careful design of control fields. In this work, we introduce a promising and versatile dynamic control neural network tailored to optimize control fields. We address the problem of suppressing defect density and enhancing cat-state fidelity during the passage across the critical point in the quantum Ising model. Our method facilitates seamless transitions between different objective functions by adjusting the {optimization strategy}. In comparison to gradient-based power-law quench methods, our approach demonstrates significant advantages for both small system sizes and long-term evolutions. We provide a detailed analysis of the specific forms of control fields and summarize common features for experimental implementation. Furthermore, numerical simulations demonstrate the robustness of our proposal against random noise and spin number fluctuations. The optimized defect density and cat-state fidelity exhibit a transition at a critical ratio of the quench duration to the system size, coinciding with the quantum speed limit for quantum evolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.05940v1-abstract-full').style.display = 'none'; document.getElementById('2404.05940v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 9 figures; Accepted in Phys. Rev. A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Physical Review A 109, 042428 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.07461">arXiv:2402.07461</a> <span> [<a href="https://arxiv.org/pdf/2402.07461">pdf</a>, <a href="https://arxiv.org/format/2402.07461">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> </div> </div> <p class="title is-5 mathjax"> Simulating the spin-boson model with a controllable reservoir in an ion trap </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+G+-">G. -X. Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y+-">Y. -K. Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Yao%2C+R">R. Yao</a>, <a href="/search/quant-ph?searchtype=author&query=Lian%2C+W+-">W. -Q. Lian</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z+-">Z. -J. Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y+-">Y. -L. Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">C. Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+Y">Y. Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y+-">Y. -Z. Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Qi%2C+B+-">B. -X. Qi</a>, <a href="/search/quant-ph?searchtype=author&query=Hou%2C+P+-">P. -Y. Hou</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Z+-">Z. -C. Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=He%2C+L">L. He</a>, <a href="/search/quant-ph?searchtype=author&query=Duan%2C+L+-">L. -M. Duan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.07461v1-abstract-short" style="display: inline;"> The spin-boson model is a prototypical model for open quantum dynamics. Here we simulate the spin-boson model using a chain of trapped ions where a spin is coupled to a structured reservoir of bosonic modes. We engineer the spectral density of the reservoir by adjusting the ion number, the target ion location, the laser detuning to the phonon sidebands, and the number of frequency components in th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07461v1-abstract-full').style.display = 'inline'; document.getElementById('2402.07461v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.07461v1-abstract-full" style="display: none;"> The spin-boson model is a prototypical model for open quantum dynamics. Here we simulate the spin-boson model using a chain of trapped ions where a spin is coupled to a structured reservoir of bosonic modes. We engineer the spectral density of the reservoir by adjusting the ion number, the target ion location, the laser detuning to the phonon sidebands, and the number of frequency components in the laser, and we observe their effects on the collapse and revival of the initially encoded information. Our work demonstrates the ion trap as a powerful platform for simulating open quantum dynamics with complicated reservoir structures. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07461v1-abstract-full').style.display = 'none'; document.getElementById('2402.07461v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.06236">arXiv:2401.06236</a> <span> [<a href="https://arxiv.org/pdf/2401.06236">pdf</a>, <a href="https://arxiv.org/format/2401.06236">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="Computational Physics">physics.comp-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/10.21468/SciPostPhys.17.2.062">10.21468/SciPostPhys.17.2.062 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Density-Matrix Mean-Field Theory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Junyi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zhengqian Cheng</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.06236v3-abstract-short" style="display: inline;"> Mean-field theories have proven to be efficient tools for exploring diverse phases of matter, complementing alternative methods that are more precise but also more computationally demanding. Conventional mean-field theories often fall short in capturing quantum fluctuations, which restricts their applicability to systems with significant quantum effects. In this article, we propose an improved mea… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.06236v3-abstract-full').style.display = 'inline'; document.getElementById('2401.06236v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.06236v3-abstract-full" style="display: none;"> Mean-field theories have proven to be efficient tools for exploring diverse phases of matter, complementing alternative methods that are more precise but also more computationally demanding. Conventional mean-field theories often fall short in capturing quantum fluctuations, which restricts their applicability to systems with significant quantum effects. In this article, we propose an improved mean-field theory, density-matrix mean-field theory (DMMFT). DMMFT constructs effective Hamiltonians, incorporating quantum environments shaped by entanglements, quantified by the reduced density matrices. Therefore, it offers a systematic and unbiased approach to account for the effects of fluctuations and entanglements in quantum ordered phases. As demonstrative examples, we show that DMMFT can not only quantitatively evaluate the renormalization of order parameters induced by quantum fluctuations, but can also detect the topological quantum phases. Additionally, we discuss the extensions of DMMFT for systems at finite temperatures and those with disorders. Our work provides an efficient approach to explore phases exhibiting unconventional quantum orders, which can be particularly beneficial for investigating frustrated spin systems in high spatial dimensions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.06236v3-abstract-full').style.display = 'none'; document.getElementById('2401.06236v3-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> 1 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">Published version in SciPost Physics, and mentioned in SciPost Selections</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> SciPost Phys. 17, 062 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.01731">arXiv:2401.01731</a> <span> [<a href="https://arxiv.org/pdf/2401.01731">pdf</a>, <a href="https://arxiv.org/format/2401.01731">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="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Extracting double-quantum coherence in two-dimensional electronic spectroscopy under pump-probe geometry </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cai%2C+M">Mao-Rui Cai</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+X">Xue Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Qian Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Yan%2C+T">Teng-Fei Yan</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+H">Hui Dong</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.01731v3-abstract-short" style="display: inline;"> Two-dimensional electronic spectroscopy (2DES) can be implemented with different geometries, e.g., BOXCARS, collinear and pump-probe geometries. The pump-probe geometry has its advantage of overlapping only two beams and reducing phase cycling steps. However, its applications are typically limited to observe the dynamics with single-quantum coherence and population, leaving the challenge to measur… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.01731v3-abstract-full').style.display = 'inline'; document.getElementById('2401.01731v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.01731v3-abstract-full" style="display: none;"> Two-dimensional electronic spectroscopy (2DES) can be implemented with different geometries, e.g., BOXCARS, collinear and pump-probe geometries. The pump-probe geometry has its advantage of overlapping only two beams and reducing phase cycling steps. However, its applications are typically limited to observe the dynamics with single-quantum coherence and population, leaving the challenge to measure the dynamics of the double-quantum (2Q) coherence, which reflects the many-body interactions. We propose an experimental technique in 2DES under pump-probe geometry with a designed pulse sequence and the signal processing method to extract 2Q coherence. In the designed pulse sequence with the probe pulse arriving earlier than pump pulses, our measured signal includes the 2Q signal as well as the zero-quantum (0Q) signal. With phase cycling and the data processing using causality enforcement, we extract the 2Q signal. The proposal is demonstrated with the rubidium atoms. And we observe the collective resonances of two-body dipole-dipole interactions of both $D_{1}$ and $D_{2}$ lines. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.01731v3-abstract-full').style.display = 'none'; document.getElementById('2401.01731v3-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> 1 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 5 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.15862">arXiv:2312.15862</a> <span> [<a href="https://arxiv.org/pdf/2312.15862">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Discovery of a topological exciton insulator with tunable momentum order </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hossain%2C+M+S">Md Shafayat Hossain</a>, <a href="/search/quant-ph?searchtype=author&query=Cochran%2C+T+A">Tyler A. Cochran</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+Y">Yu-Xiao Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+S">Songbo Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+H">Huangyu Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+X">Xiaoxiong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+X">Xiquan Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Kim%2C+B">Byunghoon Kim</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+G">Guangming Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Q">Qi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Litskevich%2C+M">Maksim Litskevich</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Junyi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Jia Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+J">Jinjin Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+J">Jia-Xin Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+X+P">Xian P. Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Denlinger%2C+J">Jonathan Denlinger</a>, <a href="/search/quant-ph?searchtype=author&query=Tallarida%2C+M">Massimo Tallarida</a>, <a href="/search/quant-ph?searchtype=author&query=Dai%2C+J">Ji Dai</a>, <a href="/search/quant-ph?searchtype=author&query=Vescovo%2C+E">Elio Vescovo</a>, <a href="/search/quant-ph?searchtype=author&query=Rajapitamahuni%2C+A">Anil Rajapitamahuni</a>, <a href="/search/quant-ph?searchtype=author&query=Miao%2C+H">Hu Miao</a>, <a href="/search/quant-ph?searchtype=author&query=Yao%2C+N">Nan Yao</a>, <a href="/search/quant-ph?searchtype=author&query=Keselman%2C+A">Anna Keselman</a>, <a href="/search/quant-ph?searchtype=author&query=Peng%2C+Y">Yingying Peng</a> , et al. (5 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="2312.15862v2-abstract-short" style="display: inline;"> Correlated topological materials often maintain a delicate balance among physical symmetries: many topological orders are symmetry protected, while most correlated phenomena arise from spontaneous symmetry breaking. It is rare to find cases where symmetry breaking induces a non-trivial topological phase. Here, we present the discovery of such a phase in Ta2Pd3Te5, where Coulomb interactions form e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.15862v2-abstract-full').style.display = 'inline'; document.getElementById('2312.15862v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.15862v2-abstract-full" style="display: none;"> Correlated topological materials often maintain a delicate balance among physical symmetries: many topological orders are symmetry protected, while most correlated phenomena arise from spontaneous symmetry breaking. It is rare to find cases where symmetry breaking induces a non-trivial topological phase. Here, we present the discovery of such a phase in Ta2Pd3Te5, where Coulomb interactions form excitons, which condense below 100 K, opening a topological gap and creating a topological excitonic insulator. Our spectroscopy reveals the full spectral bulk gap stemming from exciton condensation. This excitonic insulator state spontaneously breaks mirror symmetries but involves a very weak structural coupling, as indicated by photoemission spectroscopy, thermodynamic measurements, and a detailed structural analysis. Notably, scanning tunneling microscopy uncovers gapless boundary modes in the bulk insulating phase. Their magnetic field response, together with theoretical modeling, suggests a topological origin. These observations establish Ta2Pd3Te5 as the first confirmed topological excitonic insulator in a three-dimensional crystal. This allows to access the associated physics through bulk-sensitive techniques. Furthermore, we uncover another surprising aspect of the topological excitonic insulator, a secondary excitonic instability near 5 K that breaks the translational symmetry. The wavevector of this state shows an unprecedented magnetic field tunability. Thus, we unveil a unique sequence of topological exciton condensations in a bulk crystal, offering new opportunities to study critical behavior and excitations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.15862v2-abstract-full').style.display = 'none'; document.getElementById('2312.15862v2-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, 2025; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> Journal submission on 7th December 23 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.11615">arXiv:2312.11615</a> <span> [<a href="https://arxiv.org/pdf/2312.11615">pdf</a>, <a href="https://arxiv.org/format/2312.11615">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="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/10.1103/PhysRevB.109.195128">10.1103/PhysRevB.109.195128 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Universal structure of measurement-induced information in many-body ground states </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zihan Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Wen%2C+R">Rui Wen</a>, <a href="/search/quant-ph?searchtype=author&query=Gopalakrishnan%2C+S">Sarang Gopalakrishnan</a>, <a href="/search/quant-ph?searchtype=author&query=Vasseur%2C+R">Romain Vasseur</a>, <a href="/search/quant-ph?searchtype=author&query=Potter%2C+A+C">Andrew C. Potter</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="2312.11615v2-abstract-short" style="display: inline;"> Unlike unitary dynamics, measurements of a subsystem can induce long-range entanglement via quantum teleportation. The amount of measurement-induced entanglement or mutual information depends jointly on the measurement basis and the entanglement structure of the state (before measurement), and has operational significance for whether the state is a resource for measurement-based quantum computing,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.11615v2-abstract-full').style.display = 'inline'; document.getElementById('2312.11615v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.11615v2-abstract-full" style="display: none;"> Unlike unitary dynamics, measurements of a subsystem can induce long-range entanglement via quantum teleportation. The amount of measurement-induced entanglement or mutual information depends jointly on the measurement basis and the entanglement structure of the state (before measurement), and has operational significance for whether the state is a resource for measurement-based quantum computing, as well as for the computational complexity of simulating the state using quantum or classical computers. In this work, we examine entropic measures of measurement-induced entanglement (MIE) and information (MII) for the ground-states of quantum many-body systems in one- and two- spatial dimensions. From numerical and analytic analysis of a variety of models encompassing critical points, quantum Hall states, string-net topological orders, and Fermi liquids, we identify universal features of the long-distance structure of MIE and MII that depend only on the underlying phase or critical universality class of the state. We argue that, whereas in $1d$ the leading contributions to long-range MIE and MII are universal, in $2d$, the existence of a teleportation transition for finite-depth circuits implies that trivial $2d$ states can exhibit long-range MIE, and the universal features lie in sub-leading corrections. We introduce modified MIE measures that directly extract these universal contributions. As a corollary, we show that the leading contributions to strange-correlators, used to numerically identify topological phases, are in fact non-universal in two or more dimensions, and explain how our modified constructions enable one to isolate universal components. We discuss the implications of these results for classical- and quantum- computational simulation of quantum materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.11615v2-abstract-full').style.display = 'none'; document.getElementById('2312.11615v2-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 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14+2 pages, 10+1 figures; v2: published version, added DMRG simulation for the XXZ model</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 109, 195128 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.09487">arXiv:2312.09487</a> <span> [<a href="https://arxiv.org/pdf/2312.09487">pdf</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="Materials Science">cond-mat.mtrl-sci</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> <p class="title is-5 mathjax"> Transport response of topological hinge modes in $伪$-Bi$_4$Br$_4$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hossain%2C+M+S">Md Shafayat Hossain</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Q">Qi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Zhiwei Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Dhale%2C+N">Nikhil Dhale</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wenhao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Litskevich%2C+M">Maksim Litskevich</a>, <a href="/search/quant-ph?searchtype=author&query=Casas%2C+B">Brian Casas</a>, <a href="/search/quant-ph?searchtype=author&query=Shumiya%2C+N">Nana Shumiya</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+J">Jia-Xin Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Cochran%2C+T+A">Tyler A. Cochran</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yongkai Li</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+Y">Yu-Xiao Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Y">Ying Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+G">Guangming Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Jia Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+X+P">Xian P. Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Yao%2C+N">Nan Yao</a>, <a href="/search/quant-ph?searchtype=author&query=Neupert%2C+T">Titus Neupert</a>, <a href="/search/quant-ph?searchtype=author&query=Balicas%2C+L">Luis Balicas</a>, <a href="/search/quant-ph?searchtype=author&query=Yao%2C+Y">Yugui Yao</a>, <a href="/search/quant-ph?searchtype=author&query=Lv%2C+B">Bing Lv</a>, <a href="/search/quant-ph?searchtype=author&query=Hasan%2C+M+Z">M. Zahid Hasan</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="2312.09487v2-abstract-short" style="display: inline;"> Electronic topological phases are renowned for their unique properties, where conducting surface states exist on the boundary of an insulating three-dimensional bulk. While the transport response of the surface states has been extensively studied, the response of the topological hinge modes remains elusive. Here, we investigate a layered topological insulator $伪$-Bi$_4$Br$_4$, and provide the firs… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.09487v2-abstract-full').style.display = 'inline'; document.getElementById('2312.09487v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.09487v2-abstract-full" style="display: none;"> Electronic topological phases are renowned for their unique properties, where conducting surface states exist on the boundary of an insulating three-dimensional bulk. While the transport response of the surface states has been extensively studied, the response of the topological hinge modes remains elusive. Here, we investigate a layered topological insulator $伪$-Bi$_4$Br$_4$, and provide the first evidence for quantum transport in gapless topological hinge states existing within the insulating bulk and surface energy gaps. Our magnetoresistance measurements reveal pronounced h/e periodic (where h denotes Planck's constant and e represents the electron charge) Aharonov-Bohm oscillation. The observed periodicity, which directly reflects the enclosed area of phase-coherent electron propagation, matches the area enclosed by the sample hinges, providing compelling evidence for the quantum interference of electrons circumnavigating around the hinges. Notably, the h/e oscillations evolve as a function of magnetic field orientation, following the interference paths along the hinge modes that are allowed by topology and symmetry, and in agreement with the locations of the hinge modes according to our scanning tunneling microscopy images. Remarkably, this demonstration of quantum transport in a topological insulator can be achieved using a flake geometry and we show that it remains robust even at elevated temperatures. Our findings collectively reveal the quantum transport response of topological hinge modes with both topological nature and quantum coherence, which can be directly applied to the development of efficient quantum electronic devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.09487v2-abstract-full').style.display = 'none'; document.getElementById('2312.09487v2-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 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Nature Physics, in press (2023)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.16470">arXiv:2309.16470</a> <span> [<a href="https://arxiv.org/pdf/2309.16470">pdf</a>, <a href="https://arxiv.org/format/2309.16470">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> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.108.032616">10.1103/PhysRevA.108.032616 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Machine-learning-inspired quantum optimal control of nonadiabatic geometric quantum computation via reverse engineering </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Mao%2C+M">Meng-Yun Mao</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zheng Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Xia%2C+Y">Yan Xia</a>, <a href="/search/quant-ph?searchtype=author&query=Ole%C5%9B%2C+A+M">Andrzej M. Ole艣</a>, <a href="/search/quant-ph?searchtype=author&query=You%2C+W">Wen-Long You</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="2309.16470v1-abstract-short" style="display: inline;"> Quantum control plays an irreplaceable role in practical use of quantum computers. However, some challenges have to be overcome to find more suitable and diverse control parameters. We propose a promising and generalizable average-fidelity-based machine-learning-inspired method to optimize the control parameters, in which a neural network with periodic feature enhancement is used as an ansatz. In… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.16470v1-abstract-full').style.display = 'inline'; document.getElementById('2309.16470v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.16470v1-abstract-full" style="display: none;"> Quantum control plays an irreplaceable role in practical use of quantum computers. However, some challenges have to be overcome to find more suitable and diverse control parameters. We propose a promising and generalizable average-fidelity-based machine-learning-inspired method to optimize the control parameters, in which a neural network with periodic feature enhancement is used as an ansatz. In the implementation of a single-qubit gate by cat-state nonadiabatic geometric quantum computation via reverse engineering, compared with the control parameters in the simple form of a trigonometric function, our approach can yield significantly higher-fidelity ($>99.99\%$) phase gates, such as the $蟺/ 8$ gate (T gate). Single-qubit gates are robust against systematic noise, additive white Gaussian noise and decoherence. We numerically demonstrate that the neural network possesses the ability to expand the model space. With the help of our optimization, we provide a feasible way to implement cascaded multi-qubit gates with high quality in a bosonic system. Therefore, the machine-learning-inspired method may be feasible in quantum optimal control of nonadiabatic geometric quantum computation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.16470v1-abstract-full').style.display = 'none'; document.getElementById('2309.16470v1-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> 28 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 8 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Physical Review A 108, 032616 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.10165">arXiv:2308.10165</a> <span> [<a href="https://arxiv.org/pdf/2308.10165">pdf</a>, <a href="https://arxiv.org/format/2308.10165">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> </div> </div> <p class="title is-5 mathjax"> Counterfactual communication without a trace in the transmission channel </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Pan%2C+W">Wei-Wei Pan</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+X">Xiao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+X">Xiao-Ye Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Q">Qin-Qin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Ze-Di Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jian Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zhao-Di Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+G">Geng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Z">Zong-Quan Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chuan-Feng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+G">Guang-Can Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Dressel%2C+J">Justin Dressel</a>, <a href="/search/quant-ph?searchtype=author&query=Vaidman%2C+L">Lev Vaidman</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="2308.10165v1-abstract-short" style="display: inline;"> We report an experimental realization of a modified counterfactual communication protocol that eliminates the dominant environmental trace left by photons passing through the transmission channel. Compared to Wheeler's criterion for inferring past particle paths, as used in prior protocols, our trace criterion provide stronger support for the claim of the counterfactuality of the communication. We… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.10165v1-abstract-full').style.display = 'inline'; document.getElementById('2308.10165v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.10165v1-abstract-full" style="display: none;"> We report an experimental realization of a modified counterfactual communication protocol that eliminates the dominant environmental trace left by photons passing through the transmission channel. Compared to Wheeler's criterion for inferring past particle paths, as used in prior protocols, our trace criterion provide stronger support for the claim of the counterfactuality of the communication. We verify the lack of trace left by transmitted photons via tagging the propagation arms of an interferometric device by distinct frequency-shifts and finding that the collected photons have no frequency shift which corresponds to the transmission channel. As a proof of principle, we counterfactually transfer a quick response code image with sufficient fidelity to be scanned with a cell phone. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.10165v1-abstract-full').style.display = 'none'; document.getElementById('2308.10165v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 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/2306.16455">arXiv:2306.16455</a> <span> [<a href="https://arxiv.org/pdf/2306.16455">pdf</a>, <a href="https://arxiv.org/format/2306.16455">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> </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/PRXQuantum.4.040326">10.1103/PRXQuantum.4.040326 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Efficient sampling of noisy shallow circuits via monitored unraveling </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zihan Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Ippoliti%2C+M">Matteo Ippoliti</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="2306.16455v2-abstract-short" style="display: inline;"> We introduce a classical algorithm for sampling the output of shallow, noisy random circuits on two-dimensional qubit arrays. The algorithm builds on the recently-proposed "space-evolving block decimation" (SEBD) and extends it to the case of noisy circuits. SEBD is based on a mapping of 2D unitary circuits to 1D {\it monitored} ones, which feature measurements alongside unitary gates; it exploits… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.16455v2-abstract-full').style.display = 'inline'; document.getElementById('2306.16455v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.16455v2-abstract-full" style="display: none;"> We introduce a classical algorithm for sampling the output of shallow, noisy random circuits on two-dimensional qubit arrays. The algorithm builds on the recently-proposed "space-evolving block decimation" (SEBD) and extends it to the case of noisy circuits. SEBD is based on a mapping of 2D unitary circuits to 1D {\it monitored} ones, which feature measurements alongside unitary gates; it exploits the presence of a measurement-induced entanglement phase transition to achieve efficient (approximate) sampling below a finite critical depth $T_c$. Our noisy-SEBD algorithm unravels the action of noise into measurements, further lowering entanglement and enabling efficient classical sampling up to larger circuit depths. We analyze a class of physically-relevant noise models (unital qubit channels) within a two-replica statistical mechanics treatment, finding weak measurements to be the optimal (i.e. most disentangling) unraveling. We then locate the noisy-SEBD complexity transition as a function of circuit depth and noise strength in realistic circuit models. As an illustrative example, we show that circuits on heavy-hexagon qubit arrays with noise rates of $\approx 2\%$ per CNOT, based on IBM Quantum processors, can be efficiently sampled up to a depth of 5 iSWAP (or 10 CNOT) gate layers. Our results help sharpen the requirements for practical hardness of simulation of noisy hardware. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.16455v2-abstract-full').style.display = 'none'; document.getElementById('2306.16455v2-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 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12+7 pages, 4+7 figures; v2: published version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> PRX Quantum 4, 040326 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.00772">arXiv:2306.00772</a> <span> [<a href="https://arxiv.org/pdf/2306.00772">pdf</a>, <a href="https://arxiv.org/format/2306.00772">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> </div> </div> <p class="title is-5 mathjax"> Manipulating spatial structure of high-order quantum coherence with entangled photons </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Huang%2C+S">Shuang-Yin Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+J">Jing Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+W">Wen-Zheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Xue%2C+S">Shu-Tian Xue</a>, <a href="/search/quant-ph?searchtype=author&query=Lou%2C+Y">Yan-Chao Lou</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zhi-Feng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+C">Chao Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+F">Fei Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+L">Li-Ping Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</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="2306.00772v1-abstract-short" style="display: inline;"> High-order quantum coherence reveals the statistical correlation of quantum particles. Manipulation of quantum coherence of light in temporal domain enables to produce single-photon source, which has become one of the most important quantum resources. High-order quantum coherence in spatial domain plays a crucial role in a variety of applications, such as quantum imaging, holography and microscopy… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.00772v1-abstract-full').style.display = 'inline'; document.getElementById('2306.00772v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.00772v1-abstract-full" style="display: none;"> High-order quantum coherence reveals the statistical correlation of quantum particles. Manipulation of quantum coherence of light in temporal domain enables to produce single-photon source, which has become one of the most important quantum resources. High-order quantum coherence in spatial domain plays a crucial role in a variety of applications, such as quantum imaging, holography and microscopy. However, the active control of high-order spatial quantum coherence remains a challenging task. Here we predict theoretically and demonstrate experimentally the first active manipulation of high-order spatial quantum coherence by mapping the entanglement of spatially structured photons. Our results not only enable to inject new strength into current applications, but also provide new possibilities towards more wide applications of high-order quantum coherence. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.00772v1-abstract-full').style.display = 'none'; document.getElementById('2306.00772v1-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> 1 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 5 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/2304.02480">arXiv:2304.02480</a> <span> [<a href="https://arxiv.org/pdf/2304.02480">pdf</a>, <a href="https://arxiv.org/format/2304.02480">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="Machine Learning">cs.LG</span> </div> </div> <p class="title is-5 mathjax"> Quantum Imitation Learning </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zhihao Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+K">Kaining Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+L">Li Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Tao%2C+D">Dacheng Tao</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="2304.02480v1-abstract-short" style="display: inline;"> Despite remarkable successes in solving various complex decision-making tasks, training an imitation learning (IL) algorithm with deep neural networks (DNNs) suffers from the high computation burden. In this work, we propose quantum imitation learning (QIL) with a hope to utilize quantum advantage to speed up IL. Concretely, we develop two QIL algorithms, quantum behavioural cloning (Q-BC) and qua… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.02480v1-abstract-full').style.display = 'inline'; document.getElementById('2304.02480v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.02480v1-abstract-full" style="display: none;"> Despite remarkable successes in solving various complex decision-making tasks, training an imitation learning (IL) algorithm with deep neural networks (DNNs) suffers from the high computation burden. In this work, we propose quantum imitation learning (QIL) with a hope to utilize quantum advantage to speed up IL. Concretely, we develop two QIL algorithms, quantum behavioural cloning (Q-BC) and quantum generative adversarial imitation learning (Q-GAIL). Q-BC is trained with a negative log-likelihood loss in an off-line manner that suits extensive expert data cases, whereas Q-GAIL works in an inverse reinforcement learning scheme, which is on-line and on-policy that is suitable for limited expert data cases. For both QIL algorithms, we adopt variational quantum circuits (VQCs) in place of DNNs for representing policies, which are modified with data re-uploading and scaling parameters to enhance the expressivity. We first encode classical data into quantum states as inputs, then perform VQCs, and finally measure quantum outputs to obtain control signals of agents. Experiment results demonstrate that both Q-BC and Q-GAIL can achieve comparable performance compared to classical counterparts, with the potential of quantum speed-up. To our knowledge, we are the first to propose the concept of QIL and conduct pilot studies, which paves the way for the quantum era. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.02480v1-abstract-full').style.display = 'none'; document.getElementById('2304.02480v1-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 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Manuscript submitted to a journal for review on January 5, 2022</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.16336">arXiv:2211.16336</a> <span> [<a href="https://arxiv.org/pdf/2211.16336">pdf</a>, <a href="https://arxiv.org/format/2211.16336">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> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.129.263602">10.1103/PhysRevLett.129.263602 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Hong-Ou-Mandel Interference between Two Hyper-Entangled Photons Enables Observation of Symmetric and Anti-Symmetric Particle Exchange Phases </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zhi-Feng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+C">Chao Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+J">Jia-Min Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+B">Bo-Wen Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Lou%2C+Y">Yan-Chao Lou</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Y">Yu-Xiang Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Xue%2C+S">Shu-Tian Xue</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zhi-Hong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+W">Wen-Zheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</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="2211.16336v1-abstract-short" style="display: inline;"> Two-photon Hong-Ou-Mandel (HOM) interference is a fundamental quantum effect with no classical counterpart. The exiting researches on two-photon interference were mainly limited in one degree of freedom (DoF), hence it is still a challenge to realize the quantum interference in multiple DoFs. Here we demonstrate the HOM interference between two hyper-entangled photons in two DoFs of polarization a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.16336v1-abstract-full').style.display = 'inline'; document.getElementById('2211.16336v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.16336v1-abstract-full" style="display: none;"> Two-photon Hong-Ou-Mandel (HOM) interference is a fundamental quantum effect with no classical counterpart. The exiting researches on two-photon interference were mainly limited in one degree of freedom (DoF), hence it is still a challenge to realize the quantum interference in multiple DoFs. Here we demonstrate the HOM interference between two hyper-entangled photons in two DoFs of polarization and orbital angular momentum (OAM) for all the sixteen hyper-entangled Bell states. We observe hyper-entangled two-photon interference with bunching effect for ten symmetric states (nine Boson-Boson states, one Fermion-Fermion state) and anti-bunching effect for six anti-symmetric states (three Boson-Fermion states, three Fermion-Boson states). More interestingly, expanding the Hilbert space by introducing an extra DoF for two photons enables to transfer the unmeasurable external phase in the initial DoF to a measurable internal phase in the expanded two DoFs. We directly measured the symmetric exchange phases being $0.012 \pm 0.002$, $0.025 \pm 0.002$ and $0.027 \pm 0.002$ in radian for the three Boson states in OAM and the anti-symmetric exchange phase being $0.991 蟺\pm 0.002$ in radian for the other Fermion state, as theoretical predictions. Our work may not only pave the way for more wide applications of quantum interference, but also develop new technologies by expanding Hilbert space in more DoFs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.16336v1-abstract-full').style.display = 'none'; document.getElementById('2211.16336v1-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> 29 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">Accepted by Physical Review Letters</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.12889">arXiv:2209.12889</a> <span> [<a href="https://arxiv.org/pdf/2209.12889">pdf</a>, <a href="https://arxiv.org/format/2209.12889">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="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/s41567-023-02199-w">10.1038/s41567-023-02199-w <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Characterizing a non-equilibrium phase transition on a quantum computer </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Chertkov%2C+E">Eli Chertkov</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zihan Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Potter%2C+A+C">Andrew C. Potter</a>, <a href="/search/quant-ph?searchtype=author&query=Gopalakrishnan%2C+S">Sarang Gopalakrishnan</a>, <a href="/search/quant-ph?searchtype=author&query=Gatterman%2C+T+M">Thomas M. Gatterman</a>, <a href="/search/quant-ph?searchtype=author&query=Gerber%2C+J+A">Justin A. Gerber</a>, <a href="/search/quant-ph?searchtype=author&query=Gilmore%2C+K">Kevin Gilmore</a>, <a href="/search/quant-ph?searchtype=author&query=Gresh%2C+D">Dan Gresh</a>, <a href="/search/quant-ph?searchtype=author&query=Hall%2C+A">Alex Hall</a>, <a href="/search/quant-ph?searchtype=author&query=Hankin%2C+A">Aaron Hankin</a>, <a href="/search/quant-ph?searchtype=author&query=Matheny%2C+M">Mitchell Matheny</a>, <a href="/search/quant-ph?searchtype=author&query=Mengle%2C+T">Tanner Mengle</a>, <a href="/search/quant-ph?searchtype=author&query=Hayes%2C+D">David Hayes</a>, <a href="/search/quant-ph?searchtype=author&query=Neyenhuis%2C+B">Brian Neyenhuis</a>, <a href="/search/quant-ph?searchtype=author&query=Stutz%2C+R">Russell Stutz</a>, <a href="/search/quant-ph?searchtype=author&query=Foss-Feig%2C+M">Michael Foss-Feig</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="2209.12889v3-abstract-short" style="display: inline;"> At transitions between phases of matter, physical systems can exhibit universal behavior independent of their microscopic details. Probing such behavior in quantum many-body systems is a challenging and practically important problem that can be solved by quantum computers, potentially exponentially faster than by classical computers. In this work, we use the Quantinuum H1-1 quantum computer to rea… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.12889v3-abstract-full').style.display = 'inline'; document.getElementById('2209.12889v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.12889v3-abstract-full" style="display: none;"> At transitions between phases of matter, physical systems can exhibit universal behavior independent of their microscopic details. Probing such behavior in quantum many-body systems is a challenging and practically important problem that can be solved by quantum computers, potentially exponentially faster than by classical computers. In this work, we use the Quantinuum H1-1 quantum computer to realize a quantum extension of a simple classical disease spreading process that is known to exhibit a non-equilibrium phase transition between an active and absorbing state. Using techniques such as qubit-reuse and error avoidance based on real-time conditional logic (utilized extensively in quantum error correction), we are able to implement large instances of the model with $73$ sites and up to $72$ circuit layers, and quantitatively determine the model's critical properties. This work demonstrates how quantum computers capable of mid-circuit resets, measurements, and conditional logic enable the study of difficult problems in quantum many-body physics: the simulation of open quantum system dynamics and non-equilibrium phase transitions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.12889v3-abstract-full').style.display = 'none'; document.getElementById('2209.12889v3-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 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 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">7 pages, 4 figures; supplement 18 pages, 19 figures, 1 table; Updated acknowledgements</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nat. Phys. (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.09831">arXiv:2207.09831</a> <span> [<a href="https://arxiv.org/pdf/2207.09831">pdf</a>, <a href="https://arxiv.org/format/2207.09831">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="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.129.254301">10.1103/PhysRevLett.129.254301 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of pi/2 modes in an acoustic Floquet system </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zheyu Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Bomantara%2C+R+W">Raditya Weda Bomantara</a>, <a href="/search/quant-ph?searchtype=author&query=Xue%2C+H">Haoran Xue</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+W">Weiwei Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+J">Jiangbin Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+B">Baile Zhang</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="2207.09831v1-abstract-short" style="display: inline;"> Topological phases of matter have remained an active area of research in the last few decades. Periodic driving is known to be a powerful tool for enriching such exotic phases, which leads to various phenomena with no static analogs. One such phenomenon is the emergence of the elusive $pi/2$ modes, i.e., a type of topological boundary state pinned at a quarter of the driving frequency. The latter… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.09831v1-abstract-full').style.display = 'inline'; document.getElementById('2207.09831v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.09831v1-abstract-full" style="display: none;"> Topological phases of matter have remained an active area of research in the last few decades. Periodic driving is known to be a powerful tool for enriching such exotic phases, which leads to various phenomena with no static analogs. One such phenomenon is the emergence of the elusive $pi/2$ modes, i.e., a type of topological boundary state pinned at a quarter of the driving frequency. The latter may lead to the formation of Floquet parafermions in the presence of interaction, which is known to support more computational power than Majorana particles. In this work, we experimentally verify the signature of $蟺/2$ modes in an acoustic waveguide array, which is designed to simulate a square-root periodically driven Su-Schrieffer-Heeger model. This is accomplished by confirming the $4T$-periodicity ($T$ being the driving period) profile of an initial-boundary excitation, which we also show theoretically to be the smoking gun evidence of $蟺/2$ modes. Our findings are expected to motivate further studies of $蟺/2$ modes in quantum systems for potential technological applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.09831v1-abstract-full').style.display = 'none'; document.getElementById('2207.09831v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 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">6 pages, 3 figure. Comments are welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.12042">arXiv:2206.12042</a> <span> [<a href="https://arxiv.org/pdf/2206.12042">pdf</a>, <a href="https://arxiv.org/format/2206.12042">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> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.129.050402">10.1103/PhysRevLett.129.050402 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental Demonstration of Quantum Pseudotelepathy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xu%2C+J">Jia-Min Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhen%2C+Y">Yi-Zheng Zhen</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Y">Yu-Xiang Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+K">Kai Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2206.12042v2-abstract-short" style="display: inline;"> Quantum pseudotelepathy is a strong form of nonlocality. Different from the conventional non-local games where quantum strategies win statistically, e.g., the Clauser-Horne-Shimony-Holt game, quantum pseudotelepathy in principle allows quantum players to with probability 1. In this work, we report a faithful experimental demonstration of quantum pseudotelepathy via playing the non-local version of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.12042v2-abstract-full').style.display = 'inline'; document.getElementById('2206.12042v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.12042v2-abstract-full" style="display: none;"> Quantum pseudotelepathy is a strong form of nonlocality. Different from the conventional non-local games where quantum strategies win statistically, e.g., the Clauser-Horne-Shimony-Holt game, quantum pseudotelepathy in principle allows quantum players to with probability 1. In this work, we report a faithful experimental demonstration of quantum pseudotelepathy via playing the non-local version of Mermin-Peres magic square game, where Alice and Bob cooperatively fill in a 3 by 3 magic square. We adopt the hyperentanglement scheme and prepare photon pairs entangled in both the polarization and the orbital angular momentum degrees of freedom, such that the experiment is carried out in a resource-efficient manner. Under the locality and fair-sampling assumption, our results show that quantum players can simultaneously win all the queries over any classical strategy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.12042v2-abstract-full').style.display = 'none'; document.getElementById('2206.12042v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 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">6+5 pages; published version</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.07740">arXiv:2206.07740</a> <span> [<a href="https://arxiv.org/pdf/2206.07740">pdf</a>, <a href="https://arxiv.org/format/2206.07740">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="Quantum Gases">cond-mat.quant-gas</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/10.1103/PhysRevB.106.L220307">10.1103/PhysRevB.106.L220307 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A matrix product operator approach to non-equilibrium Floquet steady states </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zihan Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Potter%2C+A+C">Andrew C. Potter</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2206.07740v1-abstract-short" style="display: inline;"> We present a numerical method to simulate non-equilibrium Floquet steady states of one-dimensional periodically-driven (Floquet) many-body systems coupled to a dissipative bath, called open-system Floquet DMRG (OFDMRG). This method is based on a matrix product operator ansatz for the Floquet density matrix in frequency-space, and enables access to large systems beyond the reach of exact master-equ… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.07740v1-abstract-full').style.display = 'inline'; document.getElementById('2206.07740v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.07740v1-abstract-full" style="display: none;"> We present a numerical method to simulate non-equilibrium Floquet steady states of one-dimensional periodically-driven (Floquet) many-body systems coupled to a dissipative bath, called open-system Floquet DMRG (OFDMRG). This method is based on a matrix product operator ansatz for the Floquet density matrix in frequency-space, and enables access to large systems beyond the reach of exact master-equation or quantum trajectory simulations, while retaining information about the periodic micro-motion in Floquet steady states. An excited-state extension of this technique also allows computation of the dynamical approach to the steady state on asymptotically long timescales. We benchmark the OFDMRG approach with a driven-dissipative Ising model, and apply it to study the possibility of dissipatively stabilizing pre-thermal discrete time-crystalline order by coupling to a cold bath. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.07740v1-abstract-full').style.display = 'none'; document.getElementById('2206.07740v1-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 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">6+7 pages, 3+1 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 106, L220307 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.04175">arXiv:2204.04175</a> <span> [<a href="https://arxiv.org/pdf/2204.04175">pdf</a>, <a href="https://arxiv.org/format/2204.04175">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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/10.1063/5.0094498">10.1063/5.0094498 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Nonlinear manipulation of orbital angular momentum spectra with second- and third- harmonic generation in a quasi-periodically poled crystal </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Y">Yu-Xiang Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+B">Bo-Wen Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hao Li</a>, <a href="/search/quant-ph?searchtype=author&query=Lou%2C+Y">Yan-Chao Lou</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zhi-Feng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Ding%2C+J">Jianping Ding</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</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="2204.04175v1-abstract-short" style="display: inline;"> Optical orbital angular momentum (OAM), as an important degree of freedom of light, has been attracted extensive attention, due to its intrinsic feature of natural discrete infinite dimension. Manipulation of OAM spectra is crucial for many impressive applications from classical to quantum realms, in particular, nonlinear manipulation of OAM spectra. Here we realized the nonlinear manipulation of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.04175v1-abstract-full').style.display = 'inline'; document.getElementById('2204.04175v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.04175v1-abstract-full" style="display: none;"> Optical orbital angular momentum (OAM), as an important degree of freedom of light, has been attracted extensive attention, due to its intrinsic feature of natural discrete infinite dimension. Manipulation of OAM spectra is crucial for many impressive applications from classical to quantum realms, in particular, nonlinear manipulation of OAM spectra. Here we realized the nonlinear manipulation of OAM spectra by using the simultaneous second- and third-harmonic generation in a single nonlinear crystal of quasi-periodically poled potassium titanyl phosphate, for fundamental waves with a variety of OAM spectra, especially for customized OAM spectra of the second and third harmonics. The experimental results confirmed the theoretical predictions. Our approach not only provides a novel way to manipulate OAM spectra at new shorter wavelengths that are hard to be directly generated, but also may find new applications towards multiplexing in classical optics and high-dimensional information processing in quantum optics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.04175v1-abstract-full').style.display = 'none'; document.getElementById('2204.04175v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 April, 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">Comments:</span> <span class="has-text-grey-dark mathjax">5 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/2204.04173">arXiv:2204.04173</a> <span> [<a href="https://arxiv.org/pdf/2204.04173">pdf</a>, <a href="https://arxiv.org/format/2204.04173">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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/10.1364/OPTICA.449590">10.1364/OPTICA.449590 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Third-harmonic generation of spatially structured light in a quasi-periodically poled crystal </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Lou%2C+Y">Yan-Chao Lou</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Y">Yu-Xiang Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Ding%2C+J">Jianping Ding</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</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="2204.04173v1-abstract-short" style="display: inline;"> Nonlinear optical processes of spatially structured light, including optical vortex and vector optical fields, have stimulated a lot of interesting physical effects and found a variety of important applications ranging from optical imaging to quantum information processing. However, high harmonic generation of vector optical fields with space-varying polarization states is still a challenge. Here… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.04173v1-abstract-full').style.display = 'inline'; document.getElementById('2204.04173v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.04173v1-abstract-full" style="display: none;"> Nonlinear optical processes of spatially structured light, including optical vortex and vector optical fields, have stimulated a lot of interesting physical effects and found a variety of important applications ranging from optical imaging to quantum information processing. However, high harmonic generation of vector optical fields with space-varying polarization states is still a challenge. Here we demonstrate third harmonic generation of spatially structured light including vector optical fields, in a nonlinear Sagnac interferometer containing a carefully designed quasi-periodically poled potassium titanyl phosphate for the first time. The experimental results are in good agreement with the theoretical predictions. Our results will enable to manipulate spatially structured light or photons at new wavelengths and carrying higher orbital angular momentum. Our approach has the potential applications for the research of optical skyrmions and may open up new opportunities to produce spatially structured entangled photons for quantum communication and computation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.04173v1-abstract-full').style.display = 'none'; document.getElementById('2204.04173v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 April, 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">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Optica 9, 183-186 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2111.07562">arXiv:2111.07562</a> <span> [<a href="https://arxiv.org/pdf/2111.07562">pdf</a>, <a href="https://arxiv.org/format/2111.07562">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> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OE.446154">10.1364/OE.446154 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental self-testing for photonic graph states </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xu%2C+J">Jia-Min Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Q">Qing Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Y">Yu-Xiang Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+X">Xin-Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</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="2111.07562v1-abstract-short" style="display: inline;"> Graph states -- one of the most representative families of multipartite entangled states, are important resources for multiparty quantum communication, quantum error correction, and quantum computation. Device-independent certification of highly entangled graph states plays a prominent role in the quantum information processing tasks. Here we have experimentally demonstrated device-independent cer… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.07562v1-abstract-full').style.display = 'inline'; document.getElementById('2111.07562v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2111.07562v1-abstract-full" style="display: none;"> Graph states -- one of the most representative families of multipartite entangled states, are important resources for multiparty quantum communication, quantum error correction, and quantum computation. Device-independent certification of highly entangled graph states plays a prominent role in the quantum information processing tasks. Here we have experimentally demonstrated device-independent certification for multipartite graph states, by adopting the robust self-testing scheme based on scalable Bell inequalities. Specifically, the prepared multi-qubit Greenberger-Horne-Zeilinger (GHZ) states and linear cluster states achieve a high degree of Bell violation, which are beyond the nontrivial bounds of the robust self-testing scheme. Furthermore, our work paves the way to the device-independent certification of complex multipartite quantum states. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.07562v1-abstract-full').style.display = 'none'; document.getElementById('2111.07562v1-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 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.12584">arXiv:2012.12584</a> <span> [<a href="https://arxiv.org/pdf/2012.12584">pdf</a>, <a href="https://arxiv.org/format/2012.12584">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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/10.1063/5.0030512">10.1063/5.0030512 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Polarization interferometric prism: a versatile tool for generation of vector fields, measurement of topological charges and implementation of a spin-orbit Controlled-Not gate </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Ren%2C+Z">Zhi-Cheng Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zi-Mo Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xi-Lin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Ding%2C+J">Jianping Ding</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hui-Tian Wang</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="2012.12584v1-abstract-short" style="display: inline;"> Optical vortex and vector field are two important types of structured optical fields. Due to their wide applications and unique features in many scientific realms, the generation, manipulation and measurement of such fields have attracted significant interest and become very important topics. However, most ways to generate vector fields have a trade-off among flexibility, efficiency, stability, an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.12584v1-abstract-full').style.display = 'inline'; document.getElementById('2012.12584v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.12584v1-abstract-full" style="display: none;"> Optical vortex and vector field are two important types of structured optical fields. Due to their wide applications and unique features in many scientific realms, the generation, manipulation and measurement of such fields have attracted significant interest and become very important topics. However, most ways to generate vector fields have a trade-off among flexibility, efficiency, stability, and simplicity. Meanwhile, an easy and direct way to measure the topological charges, especially for high order optical vortex, is still a challenge. Here we design and manufacture a prism: polarization interferometric prism (PIP) as a single-element interferometer, which can conveniently convert an optical vortex to vector fields with high efficiency and be utilized to precisely measure the topological charge (both absolute value and sign) of an arbitrary optical vortex, even with a high order. Experimentally we generate a variety of vector fields with global fidelity ranging from 0.963 to 0.993 and measure the topological charge of an optical vortex by counting the number of petals uniformly distributed over a ring on the output intensity patterns. As a versatile tool to generate, manipulate and detect the spin-orbital state of single photons, PIP can also work in single-photon regime for quantum information processing. In experiment, the PIP is utilized as a spin-orbit Controlled-Not gate on the generated 28 two-qubit states, achieving the state fidelities ranging from 0.966 to 0.995 and demonstrating the feasibility of the PIP for single photons. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.12584v1-abstract-full').style.display = 'none'; document.getElementById('2012.12584v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">4 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/2004.04385">arXiv:2004.04385</a> <span> [<a href="https://arxiv.org/pdf/2004.04385">pdf</a>, <a href="https://arxiv.org/format/2004.04385">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/PhysRevLett.124.247701">10.1103/PhysRevLett.124.247701 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Nanoscale electrometry based on a magnetic-field-resistant spin sensor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+R">Rui Li</a>, <a href="/search/quant-ph?searchtype=author&query=Kong%2C+F">Fei Kong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+P">Pengju Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zhi Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Qin%2C+Z">Zhuoyang Qin</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+M">Mengqi Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Q">Qi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+P">Pengfei Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Ya Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+F">Fazhan Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+J">Jiangfeng Du</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2004.04385v1-abstract-short" style="display: inline;"> The nitrogen-vacancy (NV) center is a potential atomic-scale spin sensor for electric field sensing. However, its natural susceptibility to the magnetic field hinders effective detection of the electric field. Here we propose a robust electrometric method utilizing continuous dynamic decoupling (CDD) technique. During the CDD period, the NV center evolves in a dressed-state space, where the sensor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.04385v1-abstract-full').style.display = 'inline'; document.getElementById('2004.04385v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.04385v1-abstract-full" style="display: none;"> The nitrogen-vacancy (NV) center is a potential atomic-scale spin sensor for electric field sensing. However, its natural susceptibility to the magnetic field hinders effective detection of the electric field. Here we propose a robust electrometric method utilizing continuous dynamic decoupling (CDD) technique. During the CDD period, the NV center evolves in a dressed-state space, where the sensor is resistant to magnetic fields but remains sensitive to electric fields. As an example, we use this method to isolate the electric noise from a complex electro-magnetical environment near diamond surface via measuring the dephasing rate between dressed states. By reducing the surface electric noise with different covered liquids, we observe an unambiguous relation between the dephasing rate and the dielectric permittivity of the liquid, which enables a quantitative investigation of electric noise model near diamond surface. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.04385v1-abstract-full').style.display = 'none'; document.getElementById('2004.04385v1-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 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 124, 247701 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.09551">arXiv:2003.09551</a> <span> [<a href="https://arxiv.org/pdf/2003.09551">pdf</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="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OL.396561">10.1364/OL.396561 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Quantum random number generator based on room-temperature single-photon emitter in gallium nitride </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Luo%2C+Q">Qing Luo</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zedi Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+J">Junkai Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+L">Lijuan Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+H">Haizhi Song</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+G">Guangwei Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">You Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Q">Qiang Zhou</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="2003.09551v1-abstract-short" style="display: inline;"> We experimentally demonstrate a real-time quantum random number generator by using a room-temperature single-photon emitter from the defect in a commercial gallium nitride wafer. Thanks to the brightness of our single photon emitter, the raw bit generation rate is ~1.8 MHz, and the unbiased bit generation rate is ~420 kHz after von Neumann's randomness extraction procedure. Our results show that c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.09551v1-abstract-full').style.display = 'inline'; document.getElementById('2003.09551v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.09551v1-abstract-full" style="display: none;"> We experimentally demonstrate a real-time quantum random number generator by using a room-temperature single-photon emitter from the defect in a commercial gallium nitride wafer. Thanks to the brightness of our single photon emitter, the raw bit generation rate is ~1.8 MHz, and the unbiased bit generation rate is ~420 kHz after von Neumann's randomness extraction procedure. Our results show that commercial gallium nitride wafer has great potential for the development of integrated high-speed quantum random number generator devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.09551v1-abstract-full').style.display = 'none'; document.getElementById('2003.09551v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 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">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Optics Letters Vol. 45, Issue 15, 4224-4227 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1911.08267">arXiv:1911.08267</a> <span> [<a href="https://arxiv.org/pdf/1911.08267">pdf</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> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevB.101.064102">10.1103/PhysRevB.101.064102 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Optimization of the power broadening in optically detected magnetic resonance of defect spins in silicon carbide </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jun-Feng Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Cui%2C+J">Jin-Ming Cui</a>, <a href="/search/quant-ph?searchtype=author&query=Yan%2C+F">Fei-Fei Yan</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Q">Qiang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Ze-Di Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zheng-Hao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+Z">Zhi-Hai Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+J">Jin-Shi Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chuan-Feng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+G">Guang-Can Guo</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="1911.08267v1-abstract-short" style="display: inline;"> Defect spins in silicon carbide have become promising platforms with respect to quantum information processing and quantum sensing. Indeed, the optically detected magnetic resonance (ODMR) of defect spins is the cornerstone of the applications. In this work, we systematically investigate the contrast and linewidth of laser-and microwave power-dependent ODMR with respect to ensemble-divacancy spins… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.08267v1-abstract-full').style.display = 'inline'; document.getElementById('1911.08267v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1911.08267v1-abstract-full" style="display: none;"> Defect spins in silicon carbide have become promising platforms with respect to quantum information processing and quantum sensing. Indeed, the optically detected magnetic resonance (ODMR) of defect spins is the cornerstone of the applications. In this work, we systematically investigate the contrast and linewidth of laser-and microwave power-dependent ODMR with respect to ensemble-divacancy spins in silicon carbide at room temperature. The results suggest that magnetic field sensing sensitivity can be improved by a factor of 10 for the optimized laser and microwave power range. The experiment will be useful for the applications of silicon carbide defects in quantum information processing and ODMR-dependent quantum sensing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.08267v1-abstract-full').style.display = 'none'; document.getElementById('1911.08267v1-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 November, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 101, 064102 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1810.08888">arXiv:1810.08888</a> <span> [<a href="https://arxiv.org/pdf/1810.08888">pdf</a>, <a href="https://arxiv.org/format/1810.08888">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="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevApplied.10.044042">10.1103/PhysRevApplied.10.044042 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Coherent control of defect spins in silicon carbide above 550 K </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yan%2C+F">Fei-Fei Yan</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jun-Feng Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Q">Qiang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Ze-Di Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Cui%2C+J">Jin-Ming Cui</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wen-Zheng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+J">Jin-Shi Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chuan-Feng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+G">Guang-Can Guo</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1810.08888v1-abstract-short" style="display: inline;"> Great efforts have been made to the investigation of defects in silicon carbide for their attractive optical and spin properties. However, most of the researches are implemented at low and room temperature. Little is known about the spin coherent property at high temperature. Here, we experimentally demonstrate coherent control of divacancy defect spins in silicon carbide above 550 K. The spin pro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.08888v1-abstract-full').style.display = 'inline'; document.getElementById('1810.08888v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1810.08888v1-abstract-full" style="display: none;"> Great efforts have been made to the investigation of defects in silicon carbide for their attractive optical and spin properties. However, most of the researches are implemented at low and room temperature. Little is known about the spin coherent property at high temperature. Here, we experimentally demonstrate coherent control of divacancy defect spins in silicon carbide above 550 K. The spin properties of defects ranging from room temperature to 600 K are investigated, in which the zero-field-splitting is found to have a polynomial temperature dependence and the spin coherence time decreases as the temperature increases. Moreover, as an example of application, we demonstrate a thermal sensing using the Ramsey method at about 450 K. Our experimental results would be useful for the investigation of high temperature properties of defect spins and silicon carbide-based broad-temperature range quantum sensing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.08888v1-abstract-full').style.display = 'none'; document.getElementById('1810.08888v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 October, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 5 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 10, 044042 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1804.01375">arXiv:1804.01375</a> <span> [<a href="https://arxiv.org/pdf/1804.01375">pdf</a>, <a href="https://arxiv.org/format/1804.01375">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> </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.121.240402">10.1103/PhysRevLett.121.240402 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimentally Robust Self-testing for Bipartite and Tripartite Entangled States </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+W">Wen-Hao Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+G">Geng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Peng%2C+X">Xing-Xiang Peng</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+X">Xiang-Jun Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+P">Peng Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Xiao%2C+Y">Ya Xiao</a>, <a href="/search/quant-ph?searchtype=author&query=Hou%2C+Z">Zhi-Bo Hou</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Ze-Di Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yu-Chun Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+J">Jin-Shi Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chuan-Feng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+G">Guang-Can Guo</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="1804.01375v1-abstract-short" style="display: inline;"> Self-testing refers to a method with which a classical user can certify the state and measurements of quantum systems in a device-independent way. Especially, the self-testing of entangled states is of great importance in quantum information process. A comprehensible example is that violating the CHSH inequality maximally necessarily implies the bipartite shares a singlet. One essential question i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.01375v1-abstract-full').style.display = 'inline'; document.getElementById('1804.01375v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1804.01375v1-abstract-full" style="display: none;"> Self-testing refers to a method with which a classical user can certify the state and measurements of quantum systems in a device-independent way. Especially, the self-testing of entangled states is of great importance in quantum information process. A comprehensible example is that violating the CHSH inequality maximally necessarily implies the bipartite shares a singlet. One essential question in self-testing is that, when one observes a non-maximum violation, how close is the tested state to the target state (which maximally violates certain Bell inequality)? The answer to this question describes the robustness of the used self-testing criterion, which is highly important in a practical sense. Recently, J. Kaniewski predicts two analytic self-testing bounds for bipartite and tripartite systems. In this work, we experimentally investigate these two bounds with high quality two-qubit and three-qubit entanglement sources. The results show that these bounds are valid for various of entangled states we prepared, and thus, we implement robust self-testing processes which improve the previous results significantly. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.01375v1-abstract-full').style.display = 'none'; document.getElementById('1804.01375v1-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 April, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 121, 240402 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1801.07508">arXiv:1801.07508</a> <span> [<a href="https://arxiv.org/pdf/1801.07508">pdf</a>, <a href="https://arxiv.org/format/1801.07508">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="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">stat.ML</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.98.040301">10.1103/PhysRevA.98.040301 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimentally detecting a quantum change point via Bayesian inference </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yu%2C+S">Shang Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+C">Chang-Jiang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Tang%2C+J">Jian-Shun Tang</a>, <a href="/search/quant-ph?searchtype=author&query=Jia%2C+Z">Zhih-Ahn Jia</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yi-Tao Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Ke%2C+Z">Zhi-Jin Ke</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wei Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+X">Xiao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Z">Zong-Quan Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Ze-Di Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+J">Jin-Shi Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yu-Chun Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Yuan-Yuan Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+G">Guo-Yong Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chuan-Feng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+G">Guang-Can Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Sent%C3%ADs%2C+G">Gael Sent铆s</a>, <a href="/search/quant-ph?searchtype=author&query=Mu%C3%B1oz-Tapia%2C+R">Ramon Mu帽oz-Tapia</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="1801.07508v1-abstract-short" style="display: inline;"> Detecting a change point is a crucial task in statistics that has been recently extended to the quantum realm. A source state generator that emits a series of single photons in a default state suffers an alteration at some point and starts to emit photons in a mutated state. The problem consists in identifying the point where the change took place. In this work, we consider a learning agent that a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.07508v1-abstract-full').style.display = 'inline'; document.getElementById('1801.07508v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1801.07508v1-abstract-full" style="display: none;"> Detecting a change point is a crucial task in statistics that has been recently extended to the quantum realm. A source state generator that emits a series of single photons in a default state suffers an alteration at some point and starts to emit photons in a mutated state. The problem consists in identifying the point where the change took place. In this work, we consider a learning agent that applies Bayesian inference on experimental data to solve this problem. This learning machine adjusts the measurement over each photon according to the past experimental results finds the change position in an online fashion. Our results show that the local-detection success probability can be largely improved by using such a machine learning technique. This protocol provides a tool for improvement in many applications where a sequence of identical quantum states is required. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.07508v1-abstract-full').style.display = 'none'; document.getElementById('1801.07508v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 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">Journal ref:</span> Phys. Rev. A 98, 040301(R) (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1703.01452">arXiv:1703.01452</a> <span> [<a href="https://arxiv.org/pdf/1703.01452">pdf</a>, <a href="https://arxiv.org/ps/1703.01452">ps</a>, <a href="https://arxiv.org/format/1703.01452">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> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OL.42.002042">10.1364/OL.42.002042 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Degenerate cavity supporting more than 31 Laguerre-Gaussian modes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Ze-Di Cheng</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zhao-Di Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Luo%2C+X">Xi-Wang Luo</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Z">Zheng-Wei Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jian Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Q">Qiang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yi-Tao Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Tang%2C+J">Jian-Shun Tang</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+J">Jin-Shi Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chuan-Feng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+G">Guang-Can Guo</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1703.01452v2-abstract-short" style="display: inline;"> Photons propagating in Laguerre-Gaussian modes have characteristic orbital angular momentums, which are fundamental optical degrees of freedom. The orbital angular momentum of light has potential application in high capacity optical communication and even in quantum information processing. In this work, we experimentally construct a ring cavity with 4 lenses and 4 mirrors that is completely degene… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.01452v2-abstract-full').style.display = 'inline'; document.getElementById('1703.01452v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1703.01452v2-abstract-full" style="display: none;"> Photons propagating in Laguerre-Gaussian modes have characteristic orbital angular momentums, which are fundamental optical degrees of freedom. The orbital angular momentum of light has potential application in high capacity optical communication and even in quantum information processing. In this work, we experimentally construct a ring cavity with 4 lenses and 4 mirrors that is completely degenerate for Laguerre-Gaussian modes. By measuring the transmission peaks and patterns of different modes, the ring cavity is shown to supporting more than 31 Laguerre-Gaussian modes. The constructed degenerate cavity opens a new way for using the unlimited resource of available angular momentum states simultaneously. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1703.01452v2-abstract-full').style.display = 'none'; document.getElementById('1703.01452v2-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 May, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 March, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 4 figures, optics letters</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Optics Letters Vol. 42, Issue 10, pp. 2042-2045 (2017) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1301.7136">arXiv:1301.7136</a> <span> [<a href="https://arxiv.org/pdf/1301.7136">pdf</a>, <a href="https://arxiv.org/ps/1301.7136">ps</a>, <a href="https://arxiv.org/format/1301.7136">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Gases">cond-mat.quant-gas</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Heavily Enhanced Dynamic Stark Shift in a System of Bose Einstein Condensation of Photons </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fan%2C+W">Weikang Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+M">Miao Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Ze Cheng</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="1301.7136v2-abstract-short" style="display: inline;"> The dynamic Stark shift of a high-lying atom in a system of Bose Einstein condensation (BEC) of photons is discussed within the framework of nonrelativistic quantum electrodynamics (QED) theory. It is found that the Stark shift of an atom in BEC of photons is modified by a temperature dependent factor, compared to that in a normal two-dimensional photonic fluid. In photonic BEC, the value of Stark… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1301.7136v2-abstract-full').style.display = 'inline'; document.getElementById('1301.7136v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1301.7136v2-abstract-full" style="display: none;"> The dynamic Stark shift of a high-lying atom in a system of Bose Einstein condensation (BEC) of photons is discussed within the framework of nonrelativistic quantum electrodynamics (QED) theory. It is found that the Stark shift of an atom in BEC of photons is modified by a temperature dependent factor, compared to that in a normal two-dimensional photonic fluid. In photonic BEC, the value of Stark shift is always greater than that in two-dimensional free space. Physical origin of the phenomenon is presented and potential application is also discussed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1301.7136v2-abstract-full').style.display = 'none'; document.getElementById('1301.7136v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 May, 2013; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 29 January, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2013. </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, 2figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1109.4303">arXiv:1109.4303</a> <span> [<a href="https://arxiv.org/pdf/1109.4303">pdf</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="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/JOSAB.28.002915">10.1364/JOSAB.28.002915 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Violation of a Bell inequality in two-dimensional spin-orbit hypoentangled subspaces </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Chen%2C+L">Lixiang Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+X">Xiancong Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Cheng%2C+Z">Zhongqun Cheng</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="1109.4303v1-abstract-short" style="display: inline;"> Based on spin-orbit coupling induced by q-plates, we present a feasible experimental proposal for preparing two-dimensional spatially inhomogeneous polarizations of light. We further investigate the quantum correlations between these inhomogeneous polarizations of photon pairs generated by spontaneous parametric down-conversion, which in essence describe the so-called hypoentanglement that is esta… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1109.4303v1-abstract-full').style.display = 'inline'; document.getElementById('1109.4303v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1109.4303v1-abstract-full" style="display: none;"> Based on spin-orbit coupling induced by q-plates, we present a feasible experimental proposal for preparing two-dimensional spatially inhomogeneous polarizations of light. We further investigate the quantum correlations between these inhomogeneous polarizations of photon pairs generated by spontaneous parametric down-conversion, which in essence describe the so-called hypoentanglement that is established between composite spin-orbit variables of photons. The violation of the Clauser-Horne-Shimony-Holt-Bell inequality is predicted with S=2\sqrt2 to illustrate the entangled nature of the cylindrical symmetry of spatially inhomogeneous polarizations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1109.4303v1-abstract-full').style.display = 'none'; document.getElementById('1109.4303v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 September, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2011. </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">14pages,3 figures, submitted</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Journal of the Optical Society of America B 28, 2915 (2011) </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 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 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