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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Zhang%2C+C&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Zhang%2C+C&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Zhang%2C+C&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Zhang%2C+C&start=100" class="pagination-link " aria-label="Page 3" aria-current="page">3 </a> </li> <li> <a href="/search/?searchtype=author&query=Zhang%2C+C&start=150" class="pagination-link " aria-label="Page 4" aria-current="page">4 </a> </li> <li> <a href="/search/?searchtype=author&query=Zhang%2C+C&start=200" class="pagination-link " aria-label="Page 5" aria-current="page">5 </a> </li> <li><span class="pagination-ellipsis">…</span></li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.12297">arXiv:2411.12297</a> <span> [<a href="https://arxiv.org/pdf/2411.12297">pdf</a>, <a href="https://arxiv.org/format/2411.12297">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"> Quantum Indistinguishable Obfuscation via Quantum Circuit Equivalence </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yuanjing Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Shang%2C+T">Tao Shang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+K">Kun Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chenyi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+H">Haohua Du</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+X">Xueyi 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="2411.12297v1-abstract-short" style="display: inline;"> Quantum computing solutions are increasingly deployed in commercial environments through delegated computing, especially one of the most critical issues is to guarantee the confidentiality and proprietary of quantum implementations. Since the proposal of general-purpose indistinguishability obfuscation (iO) and functional encryption schemes, iO has emerged as a seemingly versatile cryptography pri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.12297v1-abstract-full').style.display = 'inline'; document.getElementById('2411.12297v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.12297v1-abstract-full" style="display: none;"> Quantum computing solutions are increasingly deployed in commercial environments through delegated computing, especially one of the most critical issues is to guarantee the confidentiality and proprietary of quantum implementations. Since the proposal of general-purpose indistinguishability obfuscation (iO) and functional encryption schemes, iO has emerged as a seemingly versatile cryptography primitive. Existing research on quantum indistinguishable obfuscation (QiO) primarily focuses on task-oriented, lacking solutions to general quantum computing. In this paper, we propose a scheme for constructing QiO via the equivalence of quantum circuits. It introduces the concept of quantum subpath sum equivalence, demonstrating that indistinguishability between two quantum circuits can be achieved by incremental changes in quantum subpaths. The restriction of security loss is solved by reducing the distinguisher to polynomial probability test. The scheme obfuscates the quantum implementation of classical functions in a path-sum specification, ensuring the indistinguishability between different quantum implementations. The results demonstrate the feasibility of indistinguishability obfuscation for general circuits and provide novel insights on intellectual property protection and secure delegated quantum computing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.12297v1-abstract-full').style.display = 'none'; document.getElementById('2411.12297v1-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.11485">arXiv:2411.11485</a> <span> [<a href="https://arxiv.org/pdf/2411.11485">pdf</a>, <a href="https://arxiv.org/ps/2411.11485">ps</a>, <a href="https://arxiv.org/format/2411.11485">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"> Quantum Coherence: A Fundamental Resource for Establishing Genuine Multipartite Correlations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Zong Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+Z">Zhihua Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zhihua Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+M">Ming Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Z">Zihang Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chengjie Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Fei%2C+S">Shao-Ming Fei</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+Z">Zhihao Ma</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="2411.11485v1-abstract-short" style="display: inline;"> We establish the profound equivalence between measures of genuine multipartite entanglement(GME) and their corresponding coherence measures. Initially we construct two distinct classes of measures for genuine multipartite entanglement utilizing real symmetric concave functions and the convex roof technique. We then demonstrate that all coherence measures for any qudit states, defined through the c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11485v1-abstract-full').style.display = 'inline'; document.getElementById('2411.11485v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.11485v1-abstract-full" style="display: none;"> We establish the profound equivalence between measures of genuine multipartite entanglement(GME) and their corresponding coherence measures. Initially we construct two distinct classes of measures for genuine multipartite entanglement utilizing real symmetric concave functions and the convex roof technique. We then demonstrate that all coherence measures for any qudit states, defined through the convex roof approach, are identical to our two classes of GME measures of the states combined with an incoherent ancilla under a unitary incoherent operation. This relationship implies that genuine multipartite entanglement can be generated from the coherence inherent in an initial state through the unitary incoherent operations. Furthermore, we explore the interplay between coherence and other forms of genuine quantum correlations, specifically genuine multipartite steering and genuine multipartite nonlocality. In the instance of special three-qubit X-states (only nonzero elements of X-state are diagonal or antidiagonal when written in an orthonormal basis), we find that genuine multipartite steering and nonlocality are present if and only if the coherence exists in the corresponding qubit states. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11485v1-abstract-full').style.display = 'none'; document.getElementById('2411.11485v1-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 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.11299">arXiv:2411.11299</a> <span> [<a href="https://arxiv.org/pdf/2411.11299">pdf</a>, <a href="https://arxiv.org/format/2411.11299">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"> Receiver-device-independent quantum secure direct communication </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+C">Cheng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Cheng Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Gu%2C+S">Shi-Pu Gu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xing-Fu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+L">Lan Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Sheng%2C+Y">Yu-Bo Sheng</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="2411.11299v1-abstract-short" style="display: inline;"> Quantum secure direct communication (QSDC) enables the message sender to directly send secure messages to the receiver through the quantum channel without keys. Device-independent (DI) and measurement-device-independent (MDI) QSDC protocols can enhance QSDC's practical security in theory. DI QSDC requires extremely high global detection efficiency and has quite low secure communication distance. D… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11299v1-abstract-full').style.display = 'inline'; document.getElementById('2411.11299v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.11299v1-abstract-full" style="display: none;"> Quantum secure direct communication (QSDC) enables the message sender to directly send secure messages to the receiver through the quantum channel without keys. Device-independent (DI) and measurement-device-independent (MDI) QSDC protocols can enhance QSDC's practical security in theory. DI QSDC requires extremely high global detection efficiency and has quite low secure communication distance. DI and MDI QSDC both require high-quality entanglement. Current entanglement sources prepare entangled photon pairs with low efficiency, largely reducing their practical communication efficiency. In the paper, we propose a single-photon-based receiver-device-independent (RDI) QSDC protocol. It only relies on the trusted single-photon source, which is nearly on-demand under current technology, and treats all the receiving devices in both communication parties as ``black-boxes''. The parties ensure the message security only from the observed statistics. We develop a numerical method to simulate its performance in practical noisy communication situation. RDI QSDC provides the same security level as MDI QSDC. Compared with DI and MDI QSDC, RDI QSDC has some advantages. First, it uses the single-photon source and single-photon measurement, which makes it obtain the practical communication efficiency about 3415 times of that in DI QSDC and easy to implement. The whole protocol is feasible with current technology. Second, it has higher photon loss robustness and noise tolerance than DI QSDC, which enables it to have a secure communication distance about 26 times of that in DI QSDC. Based on above features, the RDI QSDC protocol makes it possible to achieve highly-secure and high-efficient QSDC in the near future. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11299v1-abstract-full').style.display = 'none'; document.getElementById('2411.11299v1-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 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.11067">arXiv:2411.11067</a> <span> [<a href="https://arxiv.org/pdf/2411.11067">pdf</a>, <a href="https://arxiv.org/format/2411.11067">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-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"> Vortex information in multiphoton scalar pair production </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fan%2C+H">Hong-Hao Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Cui-Wen Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Tang%2C+S">Suo Tang</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+B">Bai-Song Xie</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="2411.11067v1-abstract-short" style="display: inline;"> Vortex information of scalar pair production in circularly polarized field is investigated in the multiphoton regime. We find that vortex orientation is related to the intrinsic orbital angular momentum of created particles associating with the helicity of absorbed photons, while the magnitude of the orbital angular momentum, i.e., the topology charge is determined by the number of absorbed photon… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11067v1-abstract-full').style.display = 'inline'; document.getElementById('2411.11067v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.11067v1-abstract-full" style="display: none;"> Vortex information of scalar pair production in circularly polarized field is investigated in the multiphoton regime. We find that vortex orientation is related to the intrinsic orbital angular momentum of created particles associating with the helicity of absorbed photons, while the magnitude of the orbital angular momentum, i.e., the topology charge is determined by the number of absorbed photons. Moreover, the properties of particle creation and vortices formation can be understood by analyzing the pair production process in quasiparticle representation. This study provides new insights into the angular momentum transfer from field to particle in the scalar pair production process. It is expected that there are similar findings about vortex features for different spin alignment in electron-positron pair production in strong fields via the topology charge as a new freedom. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.11067v1-abstract-full').style.display = 'none'; document.getElementById('2411.11067v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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, 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/2411.09150">arXiv:2411.09150</a> <span> [<a href="https://arxiv.org/pdf/2411.09150">pdf</a>, <a href="https://arxiv.org/format/2411.09150">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"> Information upper bounds in composite quantum systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Dong%2C+Z">Zhaoyang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Hou%2C+Y">Yuexian Hou</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chenguang Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yingjie 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="2411.09150v2-abstract-short" style="display: inline;"> Quantum information entropy is regarded as a measure of coherence between the observed system and the environment or between many-body. It is commonly described as the uncertainty and purity of a mixed state of a quantum system. Different from traditional information entropy, we introduce a new perspective, aiming to decompose the quantum state and focus on the total amount of information containe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09150v2-abstract-full').style.display = 'inline'; document.getElementById('2411.09150v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.09150v2-abstract-full" style="display: none;"> Quantum information entropy is regarded as a measure of coherence between the observed system and the environment or between many-body. It is commonly described as the uncertainty and purity of a mixed state of a quantum system. Different from traditional information entropy, we introduce a new perspective, aiming to decompose the quantum state and focus on the total amount of information contained in the components that constitute the legal quantum state itself. Based on $蠂^2$ divergence, we define the posterior information content of quantum pure states. We analytically proved that the upper bound of the posterior information of a 2-qubit system is exactly equal to 2. At the same time, we found that when the number of qubits n>2 in the quantum system, the process of calculating the upper bound of the posterior information can always be summarized as a standard semi-definite programming. Combined with numerical experiments, we generalized the previous hypothesis: A composite quantum system composed of n-qubits, the upper bound of the posterior information should be equal to n. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09150v2-abstract-full').style.display = 'none'; document.getElementById('2411.09150v2-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">12 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.07775">arXiv:2411.07775</a> <span> [<a href="https://arxiv.org/pdf/2411.07775">pdf</a>, <a href="https://arxiv.org/format/2411.07775">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> <p class="title is-5 mathjax"> Topological resilience of optical skyrmions in local decoherence </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+L">Li-Wen Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+S">Sheng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Cheng-Jie Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+G">Geng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yong-Sheng Zhang</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="2411.07775v1-abstract-short" style="display: inline;"> The concept of skyrmions was introduced as early as the 1960s by Tony Skyrme. The topologically protected configuration embedded in skyrmions has prompted some investigations into their fundamental properties and versatile applications, sparking interest and guiding ongoing development. The topological protection associated with skyrmions was initially observed in systems with interactions. It is… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.07775v1-abstract-full').style.display = 'inline'; document.getElementById('2411.07775v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.07775v1-abstract-full" style="display: none;"> The concept of skyrmions was introduced as early as the 1960s by Tony Skyrme. The topologically protected configuration embedded in skyrmions has prompted some investigations into their fundamental properties and versatile applications, sparking interest and guiding ongoing development. The topological protection associated with skyrmions was initially observed in systems with interactions. It is widely believed that skyrmions are stable yet relevant confirmation and empirical research remains limited. A pertinent question is whether skyrmion configurations formed by single-particle wave functions also exhibit topological stability. In this study, we affirm this hypothesis by investigating the effects of local decoherence. We analytically and numerically demonstrate the topological resilience of skyrmions and occurrence of transition points of skyrmion numbers in local decoherence of three typical decoherence channels. On the other hand, we show that these qualities are independent of the initial state. From the numerical results, we verify that inhomogeneous but continuous decoherence channels also adhere to the same behaviors and hold topological stability of skyrmions as homogeneous decoherence channels. These properties of skyrmions contribute to further applications in various areas including communication and imaging. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.07775v1-abstract-full').style.display = 'none'; document.getElementById('2411.07775v1-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 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">19 pages</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.06794">arXiv:2411.06794</a> <span> [<a href="https://arxiv.org/pdf/2411.06794">pdf</a>, <a href="https://arxiv.org/format/2411.06794">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> </div> </div> <p class="title is-5 mathjax"> Emergence of steady quantum transport in a superconducting processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+P">Pengfei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+X">Xiansong Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+N">Ning Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+H">Hang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Chu Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+J">Jinfeng Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+X">Xu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+J">Jiachen Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+S">Shibo Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+K">Ke Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yaozu Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanyu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+F">Feitong Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xuhao Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+A">Aosai Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zou%2C+Y">Yiren Zou</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+Z">Ziqi Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Cui%2C+Z">Zhengyi Cui</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Z">Zitian Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+F">Fanhao Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tingting Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+J">Jiarun Zhong</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Z">Zehang Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+L">Liangtian Zhao</a> , et al. (7 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="2411.06794v1-abstract-short" style="display: inline;"> Non-equilibrium quantum transport is crucial to technological advances ranging from nanoelectronics to thermal management. In essence, it deals with the coherent transfer of energy and (quasi-)particles through quantum channels between thermodynamic baths. A complete understanding of quantum transport thus requires the ability to simulate and probe macroscopic and microscopic physics on equal foot… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.06794v1-abstract-full').style.display = 'inline'; document.getElementById('2411.06794v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.06794v1-abstract-full" style="display: none;"> Non-equilibrium quantum transport is crucial to technological advances ranging from nanoelectronics to thermal management. In essence, it deals with the coherent transfer of energy and (quasi-)particles through quantum channels between thermodynamic baths. A complete understanding of quantum transport thus requires the ability to simulate and probe macroscopic and microscopic physics on equal footing. Using a superconducting quantum processor, we demonstrate the emergence of non-equilibrium steady quantum transport by emulating the baths with qubit ladders and realising steady particle currents between the baths. We experimentally show that the currents are independent of the microscopic details of bath initialisation, and their temporal fluctuations decrease rapidly with the size of the baths, emulating those predicted by thermodynamic baths. The above characteristics are experimental evidence of pure-state statistical mechanics and prethermalisation in non-equilibrium many-body quantum systems. Furthermore, by utilising precise controls and measurements with single-site resolution, we demonstrate the capability to tune steady currents by manipulating the macroscopic properties of the baths, including filling and spectral properties. Our investigation paves the way for a new generation of experimental exploration of non-equilibrium quantum transport in strongly correlated quantum matter. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.06794v1-abstract-full').style.display = 'none'; document.getElementById('2411.06794v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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, 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/2411.04558">arXiv:2411.04558</a> <span> [<a href="https://arxiv.org/pdf/2411.04558">pdf</a>, <a href="https://arxiv.org/format/2411.04558">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="Cryptography and Security">cs.CR</span> </div> </div> <p class="title is-5 mathjax"> Experimental Secure Multiparty Computation from Quantum Oblivious Transfer with Bit Commitment </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+K">Kai-Yi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+A">An-Jing Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Tu%2C+K">Kun Tu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+M">Ming-Han Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Qi%2C+W">Wei Qi</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Ya-Dong Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+Y">Yu Yu</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="2411.04558v1-abstract-short" style="display: inline;"> Secure multiparty computation enables collaborative computations across multiple users while preserving individual privacy, which has a wide range of applications in finance, machine learning and healthcare. Secure multiparty computation can be realized using oblivious transfer as a primitive function. In this paper, we present an experimental implementation of a quantum-secure quantum oblivious t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.04558v1-abstract-full').style.display = 'inline'; document.getElementById('2411.04558v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.04558v1-abstract-full" style="display: none;"> Secure multiparty computation enables collaborative computations across multiple users while preserving individual privacy, which has a wide range of applications in finance, machine learning and healthcare. Secure multiparty computation can be realized using oblivious transfer as a primitive function. In this paper, we present an experimental implementation of a quantum-secure quantum oblivious transfer (QOT) protocol using an adapted quantum key distribution system combined with a bit commitment scheme, surpassing previous approaches only secure in the noisy storage model. We demonstrate the first practical application of the QOT protocol by solving the private set intersection, a prime example of secure multiparty computation, where two parties aim to find common elements in their datasets without revealing any other information. In our experiments, two banks can identify common suspicious accounts without disclosing any other data. This not only proves the experimental functionality of QOT, but also showcases its real-world commercial applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.04558v1-abstract-full').style.display = 'none'; document.getElementById('2411.04558v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.04353">arXiv:2411.04353</a> <span> [<a href="https://arxiv.org/pdf/2411.04353">pdf</a>, <a href="https://arxiv.org/format/2411.04353">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="Other Condensed Matter">cond-mat.other</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computational Complexity">cs.CC</span> </div> </div> <p class="title is-5 mathjax"> On the hardness of learning ground state entanglement of geometrically local Hamiltonians </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Bouland%2C+A">Adam Bouland</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chenyi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Z">Zixin 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="2411.04353v1-abstract-short" style="display: inline;"> Characterizing the entanglement structure of ground states of local Hamiltonians is a fundamental problem in quantum information. In this work we study the computational complexity of this problem, given the Hamiltonian as input. Our main result is that to show it is cryptographically hard to determine if the ground state of a geometrically local, polynomially gapped Hamiltonian on qudits (… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.04353v1-abstract-full').style.display = 'inline'; document.getElementById('2411.04353v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.04353v1-abstract-full" style="display: none;"> Characterizing the entanglement structure of ground states of local Hamiltonians is a fundamental problem in quantum information. In this work we study the computational complexity of this problem, given the Hamiltonian as input. Our main result is that to show it is cryptographically hard to determine if the ground state of a geometrically local, polynomially gapped Hamiltonian on qudits ($d=O(1)$) has near-area law vs near-volume law entanglement. This improves prior work of Bouland et al. (arXiv:2311.12017) showing this for non-geometrically local Hamiltonians. In particular we show this problem is roughly factoring-hard in 1D, and LWE-hard in 2D. Our proof works by constructing a novel form of public-key pseudo-entanglement which is highly space-efficient, and combining this with a modification of Gottesman and Irani's quantum Turing machine to Hamiltonian construction. Our work suggests that the problem of learning so-called "gapless" quantum phases of matter might be intractable. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.04353v1-abstract-full').style.display = 'none'; document.getElementById('2411.04353v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">47 pages, 10 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/2411.03800">arXiv:2411.03800</a> <span> [<a href="https://arxiv.org/pdf/2411.03800">pdf</a>, <a href="https://arxiv.org/format/2411.03800">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"> Perturbational Decomposition Analysis for Quantum Ising Model with Weak Transverse Fields </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Youning Li</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+J">Junfeng Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chao Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+J">Jun Li</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="2411.03800v1-abstract-short" style="display: inline;"> This work presented a perturbational decomposition method for simulating quantum evolution under the one-dimensional Ising model with both longitudinal and transverse fields. By treating the transverse field terms as perturbations in the expansion, our approach is particularly effective in systems with moderate longitudinal fields and weak to moderate transverse fields relative to the coupling str… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.03800v1-abstract-full').style.display = 'inline'; document.getElementById('2411.03800v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.03800v1-abstract-full" style="display: none;"> This work presented a perturbational decomposition method for simulating quantum evolution under the one-dimensional Ising model with both longitudinal and transverse fields. By treating the transverse field terms as perturbations in the expansion, our approach is particularly effective in systems with moderate longitudinal fields and weak to moderate transverse fields relative to the coupling strength. Through systematic numerical exploration, we characterized parameter regimes and evolution time windows where the decomposition achieved measurable improvements over conventional Trotter decomposition methods. The developed perturbational approach and its characterized parameter space may provide practical guidance for choosing appropriate simulation strategies in different parameter regimes of the one-dimensional Ising model. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.03800v1-abstract-full').style.display = 'none'; document.getElementById('2411.03800v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">10 pages, 7 figures, comments weilcomed</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.20338">arXiv:2410.20338</a> <span> [<a href="https://arxiv.org/pdf/2410.20338">pdf</a>, <a href="https://arxiv.org/format/2410.20338">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-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"> Gain-Loss Coupled Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chunlei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Kim%2C+M">Mun Kim</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yi-Hui Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yi-Pu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Trivedi%2C+D">Deepanshu Trivedi</a>, <a href="/search/quant-ph?searchtype=author&query=Krasnok%2C+A">Alex Krasnok</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jianbo Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Isleifson%2C+D">Dustin Isleifson</a>, <a href="/search/quant-ph?searchtype=author&query=Roshko%2C+R">Roy Roshko</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+C">Can-Ming Hu</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="2410.20338v1-abstract-short" style="display: inline;"> Achieving oscillations with small dimensions, high power, high coherence, and low phase noise has been a long-standing goal in wave physics, driving innovations across classical electromagnetic theory and quantum physics. Key applications include electronic oscillators, lasers, and spin-torque oscillations. In recent decades, physicists have increasingly focused on harnessing passive oscillatory m… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.20338v1-abstract-full').style.display = 'inline'; document.getElementById('2410.20338v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.20338v1-abstract-full" style="display: none;"> Achieving oscillations with small dimensions, high power, high coherence, and low phase noise has been a long-standing goal in wave physics, driving innovations across classical electromagnetic theory and quantum physics. Key applications include electronic oscillators, lasers, and spin-torque oscillations. In recent decades, physicists have increasingly focused on harnessing passive oscillatory modes to manipulate these oscillations, leading to the development of diverse gain-loss coupled systems, including photon-photon, exciton-photon, photon-magnon, magnon-phonon, and magnon-magnon couplings. This review provides a comprehensive overview of these systems, exploring their fundamental physical structures, key experimental observations, and theoretical insights. By synthesizing insights from these studies, we propose future research directions to further advance the understanding and application of gain-loss coupled systems for quantum science and quantum technologies. (The field of gain-loss coupled systems is vast. The authors welcome suggestions and feedback from the community to continuously improve this review article until it is published). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.20338v1-abstract-full').style.display = 'none'; document.getElementById('2410.20338v1-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 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">20 pages, 10 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/2410.07983">arXiv:2410.07983</a> <span> [<a href="https://arxiv.org/pdf/2410.07983">pdf</a>, <a href="https://arxiv.org/format/2410.07983">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"> Characterizing Quantum Codes via the Coefficients in Knill-Laflamme Conditions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Du%2C+M">Mengxin Du</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chao Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Poon%2C+Y">Yiu-Tung Poon</a>, <a href="/search/quant-ph?searchtype=author&query=Zeng%2C+B">Bei Zeng</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="2410.07983v1-abstract-short" style="display: inline;"> Quantum error correction (QEC) is essential for protecting quantum information against noise, yet understanding the structure of the Knill-Laflamme (KL) coefficients $位_{ij}$ from the condition $PE_i^\dagger E_j P = 位_{ij} P$ remains challenging, particularly for nonadditive codes. In this work, we introduce the signature vector $\vec位(P)$, composed of the off-diagonal KL coefficients $位_{ij}$, wh… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.07983v1-abstract-full').style.display = 'inline'; document.getElementById('2410.07983v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.07983v1-abstract-full" style="display: none;"> Quantum error correction (QEC) is essential for protecting quantum information against noise, yet understanding the structure of the Knill-Laflamme (KL) coefficients $位_{ij}$ from the condition $PE_i^\dagger E_j P = 位_{ij} P$ remains challenging, particularly for nonadditive codes. In this work, we introduce the signature vector $\vec位(P)$, composed of the off-diagonal KL coefficients $位_{ij}$, where each coefficient corresponds to equivalence classes of errors counted only once. We define its Euclidean norm $位^*(P)$ as a scalar measure representing the total strength of error correlations within the code subspace defined by the projector $P$. We parameterize $P$ on a Stiefel manifold and formulate an optimization problem based on the KL conditions to systematically explore possible values of $位^*$. Moreover, we show that, for $((n,K,d))$ codes, $位^*$ is invariant under local unitary transformations. Applying our approach to the $((6, 2, 3))$ quantum code, we find that $位^*_{\text{min}} = \sqrt{0.6}$ and $位^*_{\text{max}} = 1$, with $位^* = 1$ corresponding to a known degenerate stabilizer code. We construct continuous families of new nonadditive codes parameterized by vectors in $\mathbb{R}^5$, with $位^*$ varying over the interval $[\sqrt{0.6}, 1]$. For the $((7, 2, 3))$ code, we identify $位^*_{\text{min}} = 0$ (corresponding to the non-degenerate Steane code) and $位^*_{\text{max}} = \sqrt{7}$ (corresponding to the permutation-invariant code by Pollatsek and Ruskai), and we demonstrate continuous paths connecting these extremes via cyclic codes characterized solely by $位^*$. Our findings provide new insights into the structure of quantum codes, advance the theoretical foundations of QEC, and open new avenues for investigating intricate relationships between code subspaces and error correlations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.07983v1-abstract-full').style.display = 'none'; document.getElementById('2410.07983v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 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">18 pages, 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/2410.01753">arXiv:2410.01753</a> <span> [<a href="https://arxiv.org/pdf/2410.01753">pdf</a>, <a href="https://arxiv.org/format/2410.01753">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Nuclear Experiment">nucl-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> $^{229}\mathrm{ThF}_4$ thin films for solid-state nuclear clocks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuankun Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=von+der+Wense%2C+L">Lars von der Wense</a>, <a href="/search/quant-ph?searchtype=author&query=Doyle%2C+J+F">Jack F. Doyle</a>, <a href="/search/quant-ph?searchtype=author&query=Higgins%2C+J+S">Jacob S. Higgins</a>, <a href="/search/quant-ph?searchtype=author&query=Ooi%2C+T">Tian Ooi</a>, <a href="/search/quant-ph?searchtype=author&query=Friebel%2C+H+U">Hans U. Friebel</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+J">Jun Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Elwell%2C+R">R. Elwell</a>, <a href="/search/quant-ph?searchtype=author&query=Terhune%2C+J+E+S">J. E. S. Terhune</a>, <a href="/search/quant-ph?searchtype=author&query=Morgan%2C+H+W+T">H. W. T. Morgan</a>, <a href="/search/quant-ph?searchtype=author&query=Alexandrova%2C+A+N">A. N. Alexandrova</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+H+B+T">H. B. Tran Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Derevianko%2C+A">Andrei Derevianko</a>, <a href="/search/quant-ph?searchtype=author&query=Hudson%2C+E+R">Eric R. Hudson</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="2410.01753v1-abstract-short" style="display: inline;"> After nearly fifty years of searching, the vacuum ultraviolet $^{229}$Th nuclear isomeric transition has recently been directly laser excited [1,2] and measured with high spectroscopic precision [3]. Nuclear clocks based on this transition are expected to be more robust [4,5] than and may outperform [6,7] current optical atomic clocks. They also promise sensitive tests for new physics beyond the s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.01753v1-abstract-full').style.display = 'inline'; document.getElementById('2410.01753v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.01753v1-abstract-full" style="display: none;"> After nearly fifty years of searching, the vacuum ultraviolet $^{229}$Th nuclear isomeric transition has recently been directly laser excited [1,2] and measured with high spectroscopic precision [3]. Nuclear clocks based on this transition are expected to be more robust [4,5] than and may outperform [6,7] current optical atomic clocks. They also promise sensitive tests for new physics beyond the standard model [5,8,9]. In light of these important advances and applications, a dramatic increase in the need for $^{229}$Th spectroscopy targets in a variety of platforms is anticipated. However, the growth and handling of high-concentration $^{229}$Th-doped crystals [5] used in previous measurements [1-3,10] are challenging due to the scarcity and radioactivity of the $^{229}$Th material. Here, we demonstrate a potentially scalable solution to these problems by demonstrating laser excitation of the nuclear transition in $^{229}$ThF$_4$ thin films grown with a physical vapor deposition process, consuming only micrograms of $^{229}$Th material. The $^{229}$ThF$_4$ thin films are intrinsically compatible with photonics platforms and nanofabrication tools for integration with laser sources and detectors, paving the way for an integrated and field-deployable solid-state nuclear clock with radioactivity up to three orders of magnitude smaller than typical \thor-doped crystals [1-3,10]. The high nuclear emitter density in $^{229}$ThF$_4$ also potentially enables quantum optics studies in a new regime. Finally, we describe the operation and present the estimation of the performance of a nuclear clock based on a defect-free ThF$_4$ crystal. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.01753v1-abstract-full').style.display = 'none'; document.getElementById('2410.01753v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 October, 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">15 pages, 3 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.17530">arXiv:2409.17530</a> <span> [<a href="https://arxiv.org/pdf/2409.17530">pdf</a>, <a href="https://arxiv.org/format/2409.17530">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Disordered Systems and Neural Networks">cond-mat.dis-nn</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <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"> Strong-to-weak spontaneous breaking of 1-form symmetry and intrinsically mixed topological order </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Carolyn Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yichen Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Jian-Hao Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+C">Cenke Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Bi%2C+Z">Zhen Bi</a>, <a href="/search/quant-ph?searchtype=author&query=Luo%2C+Z">Zhu-Xi Luo</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="2409.17530v1-abstract-short" style="display: inline;"> Topological orders in 2+1d are spontaneous symmetry-breaking (SSB) phases of 1-form symmetries in pure states. The notion of symmetry is further enriched in the context of mixed states, where a symmetry can be either ``strong" or ``weak". In this work, we apply a R茅nyi-2 version of the proposed equivalence relation in [Sang, Lessa, Mong, Grover, Wang, & Hsieh, to appear] on density matrices that i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.17530v1-abstract-full').style.display = 'inline'; document.getElementById('2409.17530v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.17530v1-abstract-full" style="display: none;"> Topological orders in 2+1d are spontaneous symmetry-breaking (SSB) phases of 1-form symmetries in pure states. The notion of symmetry is further enriched in the context of mixed states, where a symmetry can be either ``strong" or ``weak". In this work, we apply a R茅nyi-2 version of the proposed equivalence relation in [Sang, Lessa, Mong, Grover, Wang, & Hsieh, to appear] on density matrices that is slightly finer than two-way channel connectivity. This equivalence relation distinguishes general 1-form strong-to-weak SSB (SW-SSB) states from phases containing pure states, and therefore labels SW-SSB states as ``intrinsically mixed". According to our equivalence relation, two states are equivalent if and only if they are connected to each other by finite Lindbladian evolution that maintains continuously varying, finite R茅nyi-2 Markov length. We then examine a natural setting for finding such density matrices: disordered ensembles. Specifically, we study the toric code with various types of disorders and show that in each case, the ensemble of ground states corresponding to different disorder realizations form a density matrix with different strong and weak SSB patterns of 1-form symmetries, including SW-SSB. Furthermore we show by perturbative calculations that these disordered ensembles form stable ``phases" in the sense that they exist over a finite parameter range, according to our equivalence relation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.17530v1-abstract-full').style.display = 'none'; document.getElementById('2409.17530v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 September, 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">30 pages, 3 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.17251">arXiv:2409.17251</a> <span> [<a href="https://arxiv.org/pdf/2409.17251">pdf</a>, <a href="https://arxiv.org/format/2409.17251">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> <p class="title is-5 mathjax"> Thermalization rates and quantum Ruelle-Pollicott resonances: insights from operator hydrodynamics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Carolyn Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Nie%2C+L">Laimei Nie</a>, <a href="/search/quant-ph?searchtype=author&query=von+Keyserlingk%2C+C">Curt von Keyserlingk</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="2409.17251v1-abstract-short" style="display: inline;"> In thermalizing many-body quantum systems without conservation laws such as ergodic Floquet and random unitary circuits, local expectation values are predicted to decay to their equilibrium values exponentially quickly. In this work we derive a relationship between said exponential decay rate $\overline{g}$ and the operator spreading properties of a local unitary evolution. A hydrodynamical pictur… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.17251v1-abstract-full').style.display = 'inline'; document.getElementById('2409.17251v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.17251v1-abstract-full" style="display: none;"> In thermalizing many-body quantum systems without conservation laws such as ergodic Floquet and random unitary circuits, local expectation values are predicted to decay to their equilibrium values exponentially quickly. In this work we derive a relationship between said exponential decay rate $\overline{g}$ and the operator spreading properties of a local unitary evolution. A hydrodynamical picture for operator spreading allows us to argue that, for random unitary circuits, $\overline{g}$ is encoded by the leading eigenvalue of a dynamical map obtained by enriching unitary dynamics with dissipation, in the limit of weak dissipation. We argue that the size of the eigenvalue does not depend on the details of this weak dissipation (given mild assumptions on properties of the ergodic dynamics), so long as it only suppresses large operators significantly. Our calculations are based on analytical results for random unitary circuits, but we argue that similar results hold for ergodic Floquet systems. These conjectures are in accordance with existing results which numerically obtain quantum many-body analogues of classical Ruelle-Pollicott resonances [T. Prosen J. Phys. A: Math. Gen. 35 L737 (2002), T. Mori, arXiv:2311.10304] by studying unitary evolutions subject to weak dissipation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.17251v1-abstract-full').style.display = 'none'; document.getElementById('2409.17251v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <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">5.5 pages, 2 figures, 7 pages supplemental material</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.15665">arXiv:2409.15665</a> <span> [<a href="https://arxiv.org/pdf/2409.15665">pdf</a>, <a href="https://arxiv.org/format/2409.15665">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"> Dynamically Optimized Nonadiabatic Holonomic Quantum Computation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xu%2C+H">Hai Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+W">Wanchun Li</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+T">Tao Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Wei%2C+K">Kejin Wei</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chengxian 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="2409.15665v1-abstract-short" style="display: inline;"> Nonadiabatic holonomic quantum computation (NHQC) is one of the promising approaches to realizing fault-tolerant quantum computation. However, due to the imperfect control in the experimental environments, the holonomic gate still needs to be further improved. Here, we propose a dynamically optimized NHQC (OPNHQC) scheme based on dynamically corrected gate technique. The scheme is implemented by c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.15665v1-abstract-full').style.display = 'inline'; document.getElementById('2409.15665v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.15665v1-abstract-full" style="display: none;"> Nonadiabatic holonomic quantum computation (NHQC) is one of the promising approaches to realizing fault-tolerant quantum computation. However, due to the imperfect control in the experimental environments, the holonomic gate still needs to be further improved. Here, we propose a dynamically optimized NHQC (OPNHQC) scheme based on dynamically corrected gate technique. The scheme is implemented by carefully designing a sequence of elementary pulses to fulfill cyclic evolution, while the dynamical phase is not accumulated. In this way, the constructed holonomic gate is immune to the error. It is found that our scheme can correct the $X$ error up to fourth order. In addition, combining with the DFS encoding our scheme can be immune to both the $X$ and $Z$ errors. Therefore, our proposed scheme offers a prospective way to the realization of scalable fault-tolerant holonomic quantum computation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.15665v1-abstract-full').style.display = 'none'; document.getElementById('2409.15665v1-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">9 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/2409.09729">arXiv:2409.09729</a> <span> [<a href="https://arxiv.org/pdf/2409.09729">pdf</a>, <a href="https://arxiv.org/format/2409.09729">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"> Quantum continual learning on a programmable superconducting processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanyu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Z">Zhide Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+L">Liangtian Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+S">Shibo Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+W">Weikang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+K">Ke Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+J">Jiachen Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yaozu Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+F">Feitong Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xuhao Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+Z">Ziqi Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Cui%2C+Z">Zhengyi Cui</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+A">Aosai Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+N">Ning Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zou%2C+Y">Yiren Zou</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tingting Li</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+F">Fanhao Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+J">Jiarun Zhong</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Z">Zehang Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Z">Zitian Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+Z">Zixuan Song</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+J">Jinfeng Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+H">Hang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+P">Pengfei Zhang</a> , et al. (10 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2409.09729v1-abstract-short" style="display: inline;"> Quantum computers may outperform classical computers on machine learning tasks. In recent years, a variety of quantum algorithms promising unparalleled potential to enhance, speed up, or innovate machine learning have been proposed. Yet, quantum learning systems, similar to their classical counterparts, may likewise suffer from the catastrophic forgetting problem, where training a model with new t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.09729v1-abstract-full').style.display = 'inline'; document.getElementById('2409.09729v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.09729v1-abstract-full" style="display: none;"> Quantum computers may outperform classical computers on machine learning tasks. In recent years, a variety of quantum algorithms promising unparalleled potential to enhance, speed up, or innovate machine learning have been proposed. Yet, quantum learning systems, similar to their classical counterparts, may likewise suffer from the catastrophic forgetting problem, where training a model with new tasks would result in a dramatic performance drop for the previously learned ones. This problem is widely believed to be a crucial obstacle to achieving continual learning of multiple sequential tasks. Here, we report an experimental demonstration of quantum continual learning on a fully programmable superconducting processor. In particular, we sequentially train a quantum classifier with three tasks, two about identifying real-life images and the other on classifying quantum states, and demonstrate its catastrophic forgetting through experimentally observed rapid performance drops for prior tasks. To overcome this dilemma, we exploit the elastic weight consolidation strategy and show that the quantum classifier can incrementally learn and retain knowledge across the three distinct tasks, with an average prediction accuracy exceeding 92.3%. In addition, for sequential tasks involving quantum-engineered data, we demonstrate that the quantum classifier can achieve a better continual learning performance than a commonly used classical feedforward network with a comparable number of variational parameters. Our results establish a viable strategy for empowering quantum learning systems with desirable adaptability to multiple sequential tasks, marking an important primary experimental step towards the long-term goal of achieving quantum artificial general intelligence. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.09729v1-abstract-full').style.display = 'none'; document.getElementById('2409.09729v1-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 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">21 pages, 14 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/2409.03217">arXiv:2409.03217</a> <span> [<a href="https://arxiv.org/pdf/2409.03217">pdf</a>, <a href="https://arxiv.org/format/2409.03217">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"> Experimental Catalytic Amplification of Asymmetry </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chao Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+X">Xiao-Min Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Ding%2C+F">Feng Ding</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+X">Xue-Yuan Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+Y">Yu Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+B">Bi-Heng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+Y">Yun-Feng Huang</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="2409.03217v2-abstract-short" style="display: inline;"> The manipulation and transformation of quantum resources are key parts of quantum mechanics. Among them, asymmetry is one of the most useful operational resources, which is widely used in quantum clocks, quantum metrology, and other tasks. Recent studies have shown that the asymmetry of quantum states can be significantly amplified with the assistance of correlating catalysts which are finite-dime… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.03217v2-abstract-full').style.display = 'inline'; document.getElementById('2409.03217v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.03217v2-abstract-full" style="display: none;"> The manipulation and transformation of quantum resources are key parts of quantum mechanics. Among them, asymmetry is one of the most useful operational resources, which is widely used in quantum clocks, quantum metrology, and other tasks. Recent studies have shown that the asymmetry of quantum states can be significantly amplified with the assistance of correlating catalysts which are finite-dimensional auxiliaries. In the experiment, we perform translationally invariant operations, ensuring that the asymmetric resources of the entire system remain non-increasing, on a composite system composed of a catalytic system and a quantum system. The experimental results demonstrate an asymmetry amplification of 0.0172\pm0.0022 in the system following the catalytic process. Our work showcases the potential of quantum catalytic processes and is expected to inspire further research in the field of quantum resource theories. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.03217v2-abstract-full').style.display = 'none'; document.getElementById('2409.03217v2-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 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 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">17pages,7figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.00601">arXiv:2409.00601</a> <span> [<a href="https://arxiv.org/pdf/2409.00601">pdf</a>, <a href="https://arxiv.org/format/2409.00601">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"> Geometric two-qubit gates in silicon-based double quantum dots </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Y">Yong-Yang Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Wei%2C+K">Kejin Wei</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chengxian 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="2409.00601v1-abstract-short" style="display: inline;"> Achieving high-fidelity two-qubit gates is crucial for spin qubits in silicon double quantum dots. However, the two-qubit gates in experiments are easily suffered from charge noise, which is still a key challenge. Geometric gates which implement gate operations employing pure geometric phase are believed to be a powerful way to realize robust control. In this work, we theoretically propose feasibl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.00601v1-abstract-full').style.display = 'inline'; document.getElementById('2409.00601v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.00601v1-abstract-full" style="display: none;"> Achieving high-fidelity two-qubit gates is crucial for spin qubits in silicon double quantum dots. However, the two-qubit gates in experiments are easily suffered from charge noise, which is still a key challenge. Geometric gates which implement gate operations employing pure geometric phase are believed to be a powerful way to realize robust control. In this work, we theoretically propose feasible strategy to implement geometric two-qubit gates for silicon-based spin qubits considering experimental control environments. By working in the suitable region where the local magnetic field gradient is much larger than the exchange interaction, we are able to implement entangling and non-entangling geometric gates via analytical and numerical methods. It is found that the implemented geometric gates can obtain fidelities surpassing 99\% for the noise level related to the experiments. Also, they can outperform the dynamical opertations. Our work paves a way to implement high-fidelity geometric gate for spin qubits in silicon. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.00601v1-abstract-full').style.display = 'none'; document.getElementById('2409.00601v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 August, 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">10 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.14318">arXiv:2408.14318</a> <span> [<a href="https://arxiv.org/pdf/2408.14318">pdf</a>, <a href="https://arxiv.org/format/2408.14318">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="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Blueprint for NV center ensemble based magnetometer: precise diamond sensor material characterization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Jixing Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Kuebler%2C+M">Michael Kuebler</a>, <a href="/search/quant-ph?searchtype=author&query=Cheung%2C+C+K">Cheuk Kit Cheung</a>, <a href="/search/quant-ph?searchtype=author&query=Benke%2C+M">Magnus Benke</a>, <a href="/search/quant-ph?searchtype=author&query=Brossaud%2C+M">Mathis Brossaud</a>, <a href="/search/quant-ph?searchtype=author&query=Denisenko%2C+A">Andrej Denisenko</a>, <a href="/search/quant-ph?searchtype=author&query=Anders%2C+J">Jens Anders</a>, <a href="/search/quant-ph?searchtype=author&query=Corcione%2C+E">Emilio Corcione</a>, <a href="/search/quant-ph?searchtype=author&query=Sauer%2C+C+T">Cristina Tar铆n Sauer</a>, <a href="/search/quant-ph?searchtype=author&query=Isoya%2C+J">Junichi Isoya</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chen Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wrachtrup%2C+J">Joerg Wrachtrup</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="2408.14318v2-abstract-short" style="display: inline;"> The nitrogen-vacancy (NV) center in diamond is a promising candidate for various quantum applications, such as quantum sensing. High sensitivity in NV-based magnetic sensing requires a diamond sample with a high density of NV centers and a long electron spin dephasing time. In this work, we propose a systematic measurement method for determining the electron spin dephasing time of NV center ensemb… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.14318v2-abstract-full').style.display = 'inline'; document.getElementById('2408.14318v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.14318v2-abstract-full" style="display: none;"> The nitrogen-vacancy (NV) center in diamond is a promising candidate for various quantum applications, such as quantum sensing. High sensitivity in NV-based magnetic sensing requires a diamond sample with a high density of NV centers and a long electron spin dephasing time. In this work, we propose a systematic measurement method for determining the electron spin dephasing time of NV center ensembles and analyze the contributions to the dephasing time from various sources, including NV-NV interactions, strain distribution, $^{13}C$ nuclear spin, and P1 electron spin. We demonstrate the effectiveness of our method on a series of high-performance diamond samples and provide a comprehensive understanding of dephasing sources, enabling the optimization of NV-based quantum sensing applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.14318v2-abstract-full').style.display = 'none'; document.getElementById('2408.14318v2-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 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.11900">arXiv:2408.11900</a> <span> [<a href="https://arxiv.org/pdf/2408.11900">pdf</a>, <a href="https://arxiv.org/format/2408.11900">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> </div> </div> <p class="title is-5 mathjax"> Quantum highway: Observation of minimal and maximal speed limits for few and many-body states </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Z">Zitian Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+L">Lei Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Z">Zehang Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+L">Liang Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+Z">Zixuan Song</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+S">Shibo Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+K">Ke Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+J">Jiachen Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+F">Feitong Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xuhao Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yaozu Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanyu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+N">Ning Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zou%2C+Y">Yiren Zou</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+Z">Ziqi Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+A">Aosai Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Cui%2C+Z">Zhengyi Cui</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+F">Fanhao Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+J">Jiarun Zhong</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tingting Li</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+J">Jinfeng Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+X">Xu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+H">Hang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+P">Pengfei Zhang</a> , et al. (8 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="2408.11900v1-abstract-short" style="display: inline;"> Tracking the time evolution of a quantum state allows one to verify the thermalization rate or the propagation speed of correlations in generic quantum systems. Inspired by the energy-time uncertainty principle, bounds have been demonstrated on the maximal speed at which a quantum state can change, resulting in immediate and practical tasks. Based on a programmable superconducting quantum processo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.11900v1-abstract-full').style.display = 'inline'; document.getElementById('2408.11900v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.11900v1-abstract-full" style="display: none;"> Tracking the time evolution of a quantum state allows one to verify the thermalization rate or the propagation speed of correlations in generic quantum systems. Inspired by the energy-time uncertainty principle, bounds have been demonstrated on the maximal speed at which a quantum state can change, resulting in immediate and practical tasks. Based on a programmable superconducting quantum processor, we test the dynamics of various emulated quantum mechanical systems encompassing single- and many-body states. We show that one can test the known quantum speed limits and that modifying a single Hamiltonian parameter allows the observation of the crossover of the different bounds on the dynamics. We also unveil the observation of minimal quantum speed limits in addition to more common maximal ones, i.e., the lowest rate of change of a unitarily evolved quantum state. Our results establish a comprehensive experimental characterization of quantum speed limits and pave the way for their subsequent study in engineered non-unitary conditions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.11900v1-abstract-full').style.display = 'none'; document.getElementById('2408.11900v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">9 pages,4 figures + supplementary information</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.11226">arXiv:2408.11226</a> <span> [<a href="https://arxiv.org/pdf/2408.11226">pdf</a>, <a href="https://arxiv.org/format/2408.11226">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"> Optimizing Quantum Fourier Transformation (QFT) Kernels for Modern NISQ and FT Architectures </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Jin%2C+Y">Yuwei Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+X">Xiangyu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+M">Minghao Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+H">Henry Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Hua%2C+F">Fei Hua</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+E+Z">Eddy Z. 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="2408.11226v1-abstract-short" style="display: inline;"> Rapid development in quantum computing leads to the appearance of several quantum applications. Quantum Fourier Transformation (QFT) sits at the heart of many of these applications. Existing work leverages SAT solver or heuristics to generate a hardware-compliant circuit for QFT by inserting SWAP gates to remap logical qubits to physical qubits. However, they might face problems such as long compi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.11226v1-abstract-full').style.display = 'inline'; document.getElementById('2408.11226v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.11226v1-abstract-full" style="display: none;"> Rapid development in quantum computing leads to the appearance of several quantum applications. Quantum Fourier Transformation (QFT) sits at the heart of many of these applications. Existing work leverages SAT solver or heuristics to generate a hardware-compliant circuit for QFT by inserting SWAP gates to remap logical qubits to physical qubits. However, they might face problems such as long compilation time due to the huge search space for SAT solver or suboptimal outcome in terms of the number of cycles to finish all gate operations. In this paper, we propose a domain-specific hardware mapping approach for QFT. We unify our insight of relaxed ordering and unit exploration in QFT to search for a qubit mapping solution with the help of program synthesis tools. Our method is the first one that guarantees linear-depth QFT circuits for Google Sycamore, IBM heavy-hex, and the lattice surgery, with respect to the number of qubits. Compared with state-of-the-art approaches, our method can save up to 53% in SWAP gate and 92% in depth. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.11226v1-abstract-full').style.display = 'none'; document.getElementById('2408.11226v1-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">arXiv admin note: text overlap with arXiv:2312.16114</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.07403">arXiv:2408.07403</a> <span> [<a href="https://arxiv.org/pdf/2408.07403">pdf</a>, <a href="https://arxiv.org/ps/2408.07403">ps</a>, <a href="https://arxiv.org/format/2408.07403">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.110.042421">10.1103/PhysRevA.110.042421 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Generating Fock-state superpositions from coherent states by selective measurement </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chen-yi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Jing%2C+J">Jun Jing</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="2408.07403v2-abstract-short" style="display: inline;"> Fock states and their superpositions are exotic testbeds for nonclassical physics and valuable resources for quantum technologies. We provide a simple protocol for the quantum measurement to generate an arbitrary Fock state and certain superposed Fock states from a coherent state of a target resonator, without any carefully tailored driving. This conditional protocol can be efficiently constructed… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07403v2-abstract-full').style.display = 'inline'; document.getElementById('2408.07403v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.07403v2-abstract-full" style="display: none;"> Fock states and their superpositions are exotic testbeds for nonclassical physics and valuable resources for quantum technologies. We provide a simple protocol for the quantum measurement to generate an arbitrary Fock state and certain superposed Fock states from a coherent state of a target resonator, without any carefully tailored driving. This conditional protocol can be efficiently constructed by a sequence of joint free evolution of the resonator and an ancillary qubit, which are coupled via a Jaynes-Cummings interaction, and projective measurements on the qubit. By properly choosing the duration of each evolution-measurement cycle and the initial state of the resonator, we can generate a desired Fock state $|n\rangle$ and a superposed Fock state $(|0\rangle+|n\rangle)/\sqrt{2}$, $n\sim10$, with a fidelity over $99\%$ in less than $30$ measurements. Moreover, our protocol can be extended straightforwardly to the generation of a Bell-like state $(|00\rangle+|nn\rangle)/\sqrt{2}$ with multiple excitations in a double-resonator system. We also calculate the outcome fidelity and the success probability of our protocol in the presence of decoherence. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07403v2-abstract-full').style.display = 'none'; document.getElementById('2408.07403v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">13 pages, 14 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 110, 042421 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.07342">arXiv:2408.07342</a> <span> [<a href="https://arxiv.org/pdf/2408.07342">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Evidence of P-wave Pairing in K2Cr3As3 Superconductors from Phase-sensitive Measurement </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Z">Zhiyuan Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Dou%2C+Z">Ziwei Dou</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+A">Anqi Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Cuiwei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Hong%2C+Y">Yu Hong</a>, <a href="/search/quant-ph?searchtype=author&query=Lei%2C+X">Xincheng Lei</a>, <a href="/search/quant-ph?searchtype=author&query=Pan%2C+Y">Yue Pan</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Z">Zhongchen Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Z">Zhipeng Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yupeng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+G">Guoan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+X">Xiaofan Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+X">Xingchen Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+X">Xiao Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Lyu%2C+Z">Zhaozheng Lyu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+P">Peiling Li</a>, <a href="/search/quant-ph?searchtype=author&query=Qu%2C+F">Faming Qu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+G">Guangtong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Su%2C+D">Dong Su</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+K">Kun Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+Y">Youguo Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+L">Li Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+J">Jie Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+J">Jiangping Hu</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="2408.07342v1-abstract-short" style="display: inline;"> P-wave superconductors hold immense promise for both fundamental physics and practical applications due to their unusual pairing symmetry and potential topological superconductivity. However, the exploration of the p-wave superconductors has proved to be a complex endeavor. Not only are they rare in nature but also the identification of p-wave superconductors has been an arduous task in history. F… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07342v1-abstract-full').style.display = 'inline'; document.getElementById('2408.07342v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.07342v1-abstract-full" style="display: none;"> P-wave superconductors hold immense promise for both fundamental physics and practical applications due to their unusual pairing symmetry and potential topological superconductivity. However, the exploration of the p-wave superconductors has proved to be a complex endeavor. Not only are they rare in nature but also the identification of p-wave superconductors has been an arduous task in history. For example, phase-sensitive measurement, an experimental technique which can provide conclusive evidence for unconventional pairing, has not been implemented successfully to identify p-wave superconductors. Here, we study a recently discovered family of superconductors, A2Cr3As3 (A = K, Rb, Cs), which were proposed theoretically to be a candidate of p-wave superconductors. We fabricate superconducting quantum interference devices (SQUIDs) on exfoliated K2Cr3As3, and perform the phase-sensitive measurement. We observe that such SQUIDs exhibit a pronounced second-order harmonic component sin(2蠁) in the current-phase relation, suggesting the admixture of 0- and 蟺-phase. By carefully examining the magnetic field dependence of the oscillation patterns of critical current and Shapiro steps under microwave irradiation, we reveal a crossover from 0- to 蟺-dominating phase state and conclude that the existence of the 蟺-phase is in favor of the p-wave pairing symmetry in K2Cr3As3. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07342v1-abstract-full').style.display = 'none'; document.getElementById('2408.07342v1-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 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.04566">arXiv:2408.04566</a> <span> [<a href="https://arxiv.org/pdf/2408.04566">pdf</a>, <a href="https://arxiv.org/format/2408.04566">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Randomness versus Nonlocality in Multi-input and Multi-output Quantum Scenario </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chao Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yi Li</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+X">Xiao-Min Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+Y">Yu 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=Tura%2C+J">Jordi Tura</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+Q">Qihuang Gong</a>, <a href="/search/quant-ph?searchtype=author&query=He%2C+Q">Qiongyi He</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+B">Bi-Heng Liu</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="2408.04566v2-abstract-short" style="display: inline;"> Device-independent randomness certification based on Bell nonlocality does not require any assumptions about the devices and therefore provides adequate security. Great effort has been made to demonstrate that nonlocality is necessary for generating quantum randomness, but the minimal resource required for random number generation has not been clarified. Here we first prove and experimentally demo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.04566v2-abstract-full').style.display = 'inline'; document.getElementById('2408.04566v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.04566v2-abstract-full" style="display: none;"> Device-independent randomness certification based on Bell nonlocality does not require any assumptions about the devices and therefore provides adequate security. Great effort has been made to demonstrate that nonlocality is necessary for generating quantum randomness, but the minimal resource required for random number generation has not been clarified. Here we first prove and experimentally demonstrate that violating any two-input Bell inequality is both necessary and sufficient for certifying randomness, however, for the multi-input cases, this sufficiency ceases to apply, leading to certain states exhibiting Bell nonlocality without the capability to certify randomness. We examine two typical classes of Bell inequalities with multi-input and multi-output, the facet inequalities and Salavrakos-Augusiak-Tura-Wittek-Ac铆n-Pironio Bell inequalities, in the high-dimensional photonic system, and observe the violation of the latter one can always certify randomness which is not true for the former. The private randomness with a generation rate of 1.867\pm0.018 bits per photon pair is obtained in the scenario of Salavrakos-Augusiak-Tura-Wittek-Ac铆n-Pironio Bell inequalities with 3-input and 4-output. Our work unravels the internal connection between randomness and nonlocality, and effectively enhances the performance of tasks such as device-independent random number generation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.04566v2-abstract-full').style.display = 'none'; document.getElementById('2408.04566v2-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 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">25 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.03801">arXiv:2408.03801</a> <span> [<a href="https://arxiv.org/pdf/2408.03801">pdf</a>, <a href="https://arxiv.org/format/2408.03801">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"> Hamiltonian learning for 300 trapped ion qubits with long-range couplings </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S+-">S. -A. Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y+-">Y. -K. Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+J">J. Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+L">L. Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Y. Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Lian%2C+W+-">W. -Q. Lian</a>, <a href="/search/quant-ph?searchtype=author&query=Yao%2C+R">R. Yao</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=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=He%2C+L">L. He</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Z+-">Z. -C. Zhou</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="2408.03801v1-abstract-short" style="display: inline;"> Quantum simulators with hundreds of qubits and engineerable Hamiltonians have the potential to explore quantum many-body models that are intractable for classical computers. However, learning the simulated Hamiltonian, a prerequisite for any applications of a quantum simulator, remains an outstanding challenge due to the fast increasing time cost with the qubit number and the lack of high-fidelity… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.03801v1-abstract-full').style.display = 'inline'; document.getElementById('2408.03801v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.03801v1-abstract-full" style="display: none;"> Quantum simulators with hundreds of qubits and engineerable Hamiltonians have the potential to explore quantum many-body models that are intractable for classical computers. However, learning the simulated Hamiltonian, a prerequisite for any applications of a quantum simulator, remains an outstanding challenge due to the fast increasing time cost with the qubit number and the lack of high-fidelity universal gate operations in the noisy intermediate-scale quantum era. Here we demonstrate the Hamiltonian learning of a two-dimensional ion trap quantum simulator with 300 qubits. We employ global manipulations and single-qubit-resolved state detection to efficiently learn the all-to-all-coupled Ising model Hamiltonian, with the required quantum resources scaling at most linearly with the qubit number. Our work paves the way for wide applications of large-scale ion trap quantum simulators. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.03801v1-abstract-full').style.display = 'none'; document.getElementById('2408.03801v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.12347">arXiv:2407.12347</a> <span> [<a href="https://arxiv.org/pdf/2407.12347">pdf</a>, <a href="https://arxiv.org/format/2407.12347">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"> Improved Nonlocality Certification via Bouncing between Bell Operators and Inequalities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+W">Weikang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+M">Mengyao Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+K">Ke Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+S">Shibo Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Z">Zhide Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+J">Jiachen Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yaozu Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanyu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+F">Feitong Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xuhao Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Cui%2C+Z">Zhengyi Cui</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+A">Aosai Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+N">Ning Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zou%2C+Y">Yiren Zou</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+F">Fanhao Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+J">Jiarun Zhong</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Z">Zehang Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Z">Zitian Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+P">Pengfei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hekang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+Q">Qiujiang Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Zhen Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+D">Dong-Ling Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+C">Chao Song</a> , et al. (3 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="2407.12347v1-abstract-short" style="display: inline;"> Bell nonlocality is an intrinsic feature of quantum mechanics, which can be certified via the violation of Bell inequalities. It is therefore a fundamental question to certify Bell nonlocality from experimental data. Here, we present an optimization scheme to improve nonlocality certification by exploring flexible mappings between Bell inequalities and Hamiltonians corresponding to the Bell operat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.12347v1-abstract-full').style.display = 'inline'; document.getElementById('2407.12347v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.12347v1-abstract-full" style="display: none;"> Bell nonlocality is an intrinsic feature of quantum mechanics, which can be certified via the violation of Bell inequalities. It is therefore a fundamental question to certify Bell nonlocality from experimental data. Here, we present an optimization scheme to improve nonlocality certification by exploring flexible mappings between Bell inequalities and Hamiltonians corresponding to the Bell operators. We show that several Hamiltonian models can be mapped to new inequalities with improved classical bounds than the original one, enabling a more robust detection of nonlocality. From the other direction, we investigate the mapping from fixed Bell inequalities to Hamiltonians, aiming to maximize quantum violations while considering experimental imperfections. As a practical demonstration, we apply this method to an XXZ-like honeycomb-lattice model utilizing over 70 superconducting qubits. The successful application of this technique, as well as combining the two directions to form an optimization loop, may open new avenues for developing more practical and noise-resilient nonlocality certification techniques and enable broader experimental explorations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.12347v1-abstract-full').style.display = 'none'; document.getElementById('2407.12347v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 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">11 pages, 5 figures, 1 table</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.05332">arXiv:2407.05332</a> <span> [<a href="https://arxiv.org/pdf/2407.05332">pdf</a>, <a href="https://arxiv.org/format/2407.05332">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"> Experimental investigation of direct non-Hermitian measurement and uncertainty relation towards high-dimensional quantum domain </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yi-Tao Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Zhao-An Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Z">Zhi-Peng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zeng%2C+X">Xiao-Dong Zeng</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+J">Jia-Ming Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wei Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Y">Yuan-Ze Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+N">Nai-Jie Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+L">Lin-Ke Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+J">Jun-You Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+Y">Yu-Hang Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Tang%2C+J">Jian-Shun Tang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chengjie Zhang</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="2407.05332v1-abstract-short" style="display: inline;"> Non-Hermitian dynamics in quantum systems have unveiled novel phenomena, yet the implementation of valid non-Hermitian quantum measurement remains a challenge, because a universal quantum projective mechanism on the complete but skewed non-Hermitian eigenstates is not explicit in experiment. This limitation hinders the direct acquisition of non-Hermitian observable statistics (e.g., non-Hermitian… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.05332v1-abstract-full').style.display = 'inline'; document.getElementById('2407.05332v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.05332v1-abstract-full" style="display: none;"> Non-Hermitian dynamics in quantum systems have unveiled novel phenomena, yet the implementation of valid non-Hermitian quantum measurement remains a challenge, because a universal quantum projective mechanism on the complete but skewed non-Hermitian eigenstates is not explicit in experiment. This limitation hinders the direct acquisition of non-Hermitian observable statistics (e.g., non-Hermitian population dynamics), also constrains investigations of non-Hermitian quantum measurement properties such as uncertainty relation. Here, we address these challenges by presenting a non-Hermitian projective protocol and investigating the non-Hermitian uncertainty relation. We derive the uncertainty relation for pseudo-Hermitian (PH) observables that is generalized beyond the Hermitian ones. We then investigate the projective properties of general quantum states onto complete non-Hermitian eigenvectors, and present a quantum simulating method to apply the valid non-Hermitian projective measurement on a direct-sum dilated space. Subsequently, we experimentally construct a quantum simulator in the quantum optical circuit and realize the 3-dimensional non-Hermitian quantum measurement on the single-photon qutrit. Employing this platform, we explore the uncertainty relation experimentally with different PH metrics. Our non-Hermitian quantum measurement method is state-independent and outputs directly the non-Hermitian quantum projective statistics, paving the way for studies of extensive non-Hermitian observable in quantum domain. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.05332v1-abstract-full').style.display = 'none'; document.getElementById('2407.05332v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 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">6 pages, 4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.19683">arXiv:2406.19683</a> <span> [<a href="https://arxiv.org/pdf/2406.19683">pdf</a>, <a href="https://arxiv.org/format/2406.19683">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"> Unified Framework for Calculating Convex Roof Resource Measures </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xuanran Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chao Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=An%2C+Z">Zheng An</a>, <a href="/search/quant-ph?searchtype=author&query=Zeng%2C+B">Bei Zeng</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.19683v1-abstract-short" style="display: inline;"> Quantum resource theories (QRTs) provide a comprehensive and practical framework for the analysis of diverse quantum phenomena. A fundamental task within QRTs is the quantification of resources inherent in a given quantum state. In this letter, we introduce a unified computational framework for a class of widely utilized quantum resource measures, derived from convex roof extensions. We establish… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.19683v1-abstract-full').style.display = 'inline'; document.getElementById('2406.19683v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.19683v1-abstract-full" style="display: none;"> Quantum resource theories (QRTs) provide a comprehensive and practical framework for the analysis of diverse quantum phenomena. A fundamental task within QRTs is the quantification of resources inherent in a given quantum state. In this letter, we introduce a unified computational framework for a class of widely utilized quantum resource measures, derived from convex roof extensions. We establish that the computation of these convex roof resource measures can be reformulated as an optimization problem over a Stiefel manifold, which can be further unconstrained through polar projection. Compared to existing methods employing semi-definite programming (SDP), gradient-based techniques or seesaw strategy, our approach not only demonstrates superior computational efficiency but also maintains applicability across various scenarios within a streamlined workflow. We substantiate the efficacy of our method by applying it to several key quantum resources, including entanglement, coherence, and magic states. Moreover, our methodology can be readily extended to other convex roof quantities beyond the domain of resource theories, suggesting broad applicability in the realm of quantum information theory. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.19683v1-abstract-full').style.display = 'none'; document.getElementById('2406.19683v1-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 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 5 figures, 2 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.18719">arXiv:2406.18719</a> <span> [<a href="https://arxiv.org/pdf/2406.18719">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Nuclear Experiment">nucl-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41586-024-07839-6">10.1038/s41586-024-07839-6 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Frequency ratio of the $^{229\mathrm{m}}$Th nuclear isomeric transition and the $^{87}$Sr atomic clock </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuankun Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Ooi%2C+T">Tian Ooi</a>, <a href="/search/quant-ph?searchtype=author&query=Higgins%2C+J+S">Jacob S. Higgins</a>, <a href="/search/quant-ph?searchtype=author&query=Doyle%2C+J+F">Jack F. Doyle</a>, <a href="/search/quant-ph?searchtype=author&query=von+der+Wense%2C+L">Lars von der Wense</a>, <a href="/search/quant-ph?searchtype=author&query=Beeks%2C+K">Kjeld Beeks</a>, <a href="/search/quant-ph?searchtype=author&query=Leitner%2C+A">Adrian Leitner</a>, <a href="/search/quant-ph?searchtype=author&query=Kazakov%2C+G">Georgy Kazakov</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+P">Peng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Thirolf%2C+P+G">Peter G. Thirolf</a>, <a href="/search/quant-ph?searchtype=author&query=Schumm%2C+T">Thorsten Schumm</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+J">Jun Ye</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.18719v2-abstract-short" style="display: inline;"> Optical atomic clocks$^{1,2}$ use electronic energy levels to precisely keep track of time. A clock based on nuclear energy levels promises a next-generation platform for precision metrology and fundamental physics studies. Thorium-229 nuclei exhibit a uniquely low energy nuclear transition within reach of state-of-the-art vacuum ultraviolet (VUV) laser light sources and have therefore been propos… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.18719v2-abstract-full').style.display = 'inline'; document.getElementById('2406.18719v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.18719v2-abstract-full" style="display: none;"> Optical atomic clocks$^{1,2}$ use electronic energy levels to precisely keep track of time. A clock based on nuclear energy levels promises a next-generation platform for precision metrology and fundamental physics studies. Thorium-229 nuclei exhibit a uniquely low energy nuclear transition within reach of state-of-the-art vacuum ultraviolet (VUV) laser light sources and have therefore been proposed for construction of the first nuclear clock$^{3,4}$. However, quantum state-resolved spectroscopy of the $^{229m}$Th isomer to determine the underlying nuclear structure and establish a direct frequency connection with existing atomic clocks has yet to be performed. Here, we use a VUV frequency comb to directly excite the narrow $^{229}$Th nuclear clock transition in a solid-state CaF$_2$ host material and determine the absolute transition frequency. We stabilize the fundamental frequency comb to the JILA $^{87}$Sr clock$^2$ and coherently upconvert the fundamental to its 7th harmonic in the VUV range using a femtosecond enhancement cavity. This VUV comb establishes a frequency link between nuclear and electronic energy levels and allows us to directly measure the frequency ratio of the $^{229}$Th nuclear clock transition and the $^{87}$Sr atomic clock. We also precisely measure the nuclear quadrupole splittings and extract intrinsic properties of the isomer. These results mark the start of nuclear-based solid-state optical clock and demonstrate the first comparison of nuclear and atomic clocks for fundamental physics studies. This work represents a confluence of precision metrology, ultrafast strong field physics, nuclear physics, and fundamental physics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.18719v2-abstract-full').style.display = 'none'; document.getElementById('2406.18719v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">22 pages, 5 figures, 1 extended data figure</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature 633, 63-70 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.17841">arXiv:2406.17841</a> <span> [<a href="https://arxiv.org/pdf/2406.17841">pdf</a>, <a href="https://arxiv.org/format/2406.17841">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="Artificial Intelligence">cs.AI</span> </div> </div> <p class="title is-5 mathjax"> Probing many-body Bell correlation depth with superconducting qubits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+K">Ke Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+W">Weikang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+S">Shibo Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+M">Mengyao Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+J">Jiachen Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yaozu Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanyu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+F">Feitong Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xuhao Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+Z">Ziqi Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+A">Aosai Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+N">Ning Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zou%2C+Y">Yiren Zou</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tingting Li</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+F">Fanhao Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+J">Jiarun Zhong</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Z">Zehang Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Z">Zitian Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+Z">Zixuan Song</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+J">Jinfeng Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+H">Hang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+X">Xu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+P">Pengfei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+W">Wenjie Jiang</a> , et al. (10 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="2406.17841v1-abstract-short" style="display: inline;"> Quantum nonlocality describes a stronger form of quantum correlation than that of entanglement. It refutes Einstein's belief of local realism and is among the most distinctive and enigmatic features of quantum mechanics. It is a crucial resource for achieving quantum advantages in a variety of practical applications, ranging from cryptography and certified random number generation via self-testing… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.17841v1-abstract-full').style.display = 'inline'; document.getElementById('2406.17841v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.17841v1-abstract-full" style="display: none;"> Quantum nonlocality describes a stronger form of quantum correlation than that of entanglement. It refutes Einstein's belief of local realism and is among the most distinctive and enigmatic features of quantum mechanics. It is a crucial resource for achieving quantum advantages in a variety of practical applications, ranging from cryptography and certified random number generation via self-testing to machine learning. Nevertheless, the detection of nonlocality, especially in quantum many-body systems, is notoriously challenging. Here, we report an experimental certification of genuine multipartite Bell correlations, which signal nonlocality in quantum many-body systems, up to 24 qubits with a fully programmable superconducting quantum processor. In particular, we employ energy as a Bell correlation witness and variationally decrease the energy of a many-body system across a hierarchy of thresholds, below which an increasing Bell correlation depth can be certified from experimental data. As an illustrating example, we variationally prepare the low-energy state of a two-dimensional honeycomb model with 73 qubits and certify its Bell correlations by measuring an energy that surpasses the corresponding classical bound with up to 48 standard deviations. In addition, we variationally prepare a sequence of low-energy states and certify their genuine multipartite Bell correlations up to 24 qubits via energies measured efficiently by parity oscillation and multiple quantum coherence techniques. Our results establish a viable approach for preparing and certifying multipartite Bell correlations, which provide not only a finer benchmark beyond entanglement for quantum devices, but also a valuable guide towards exploiting multipartite Bell correlation in a wide spectrum of practical applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.17841v1-abstract-full').style.display = 'none'; document.getElementById('2406.17841v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages,6 figures + 14 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.13999">arXiv:2406.13999</a> <span> [<a href="https://arxiv.org/pdf/2406.13999">pdf</a>, <a href="https://arxiv.org/format/2406.13999">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"> Individually Addressed Entangling Gates in a Two-Dimensional Ion Crystal </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hou%2C+Y+-">Y. -H. Hou</a>, <a href="/search/quant-ph?searchtype=author&query=Yi%2C+Y+-">Y. -J. Yi</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y+-">Y. -K. Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Y+-">Y. -Y. Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+L">L. Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Y. Wang</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=Mei%2C+Q+-">Q. -X. Mei</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+H+-">H. -X. Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+J+-">J. -Y. Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S+-">S. -A. Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+J">J. Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Qi%2C+B+-">B. -X. Qi</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+Z+-">Z. -C. Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Hou%2C+P+-">P. -Y. Hou</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="2406.13999v1-abstract-short" style="display: inline;"> Two-dimensional (2D) ion crystals have become a promising way to scale up qubit numbers for ion trap quantum information processing. However, to realize universal quantum computing in this system, individually addressed high-fidelity two-qubit entangling gates still remain challenging due to the inevitable micromotion of ions in a 2D crystal as well as the technical difficulty in 2D addressing. He… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.13999v1-abstract-full').style.display = 'inline'; document.getElementById('2406.13999v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.13999v1-abstract-full" style="display: none;"> Two-dimensional (2D) ion crystals have become a promising way to scale up qubit numbers for ion trap quantum information processing. However, to realize universal quantum computing in this system, individually addressed high-fidelity two-qubit entangling gates still remain challenging due to the inevitable micromotion of ions in a 2D crystal as well as the technical difficulty in 2D addressing. Here we demonstrate two-qubit entangling gates between any ion pairs in a 2D crystal of four ions. We use symmetrically placed crossed acousto-optic deflectors (AODs) to drive Raman transitions and achieve an addressing crosstalk error below 0.1%. We design and demonstrate a gate sequence by alternatingly addressing two target ions, making it compatible with any single-ion addressing techniques without crosstalk from multiple addressing beams. We further examine the gate performance versus the micromotion amplitude of the ions and show that its effect can be compensated by a recalibration of the laser intensity without degrading the gate fidelity. Our work paves the way for ion trap quantum computing with hundreds to thousands of qubits on a 2D ion crystal. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.13999v1-abstract-full').style.display = 'none'; document.getElementById('2406.13999v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.10344">arXiv:2406.10344</a> <span> [<a href="https://arxiv.org/pdf/2406.10344">pdf</a>, <a href="https://arxiv.org/format/2406.10344">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> <p class="title is-5 mathjax"> Phases and phase transition in Grover's algorithm with systematic noise </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Dowarah%2C+S">Sasanka Dowarah</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanwei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Khemani%2C+V">Vedika Khemani</a>, <a href="/search/quant-ph?searchtype=author&query=Kolodrubetz%2C+M+H">Michael H. Kolodrubetz</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.10344v1-abstract-short" style="display: inline;"> While limitations on quantum computation by Markovian environmental noise are well-understood in generality, their behavior for different quantum circuits and noise realizations can be less universal. Here we consider a canonical quantum algorithm - Grover's algorithm for unordered search on $L$ qubits - in the presence of systematic noise. This allows us to write the behavior as a random Floquet… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.10344v1-abstract-full').style.display = 'inline'; document.getElementById('2406.10344v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.10344v1-abstract-full" style="display: none;"> While limitations on quantum computation by Markovian environmental noise are well-understood in generality, their behavior for different quantum circuits and noise realizations can be less universal. Here we consider a canonical quantum algorithm - Grover's algorithm for unordered search on $L$ qubits - in the presence of systematic noise. This allows us to write the behavior as a random Floquet unitary, which we show is well-characterized by random matrix theory (RMT). The RMT analysis enables analytical predictions for phases and phase transitions of the many-body dynamics. We find two separate transitions. At moderate disorder $未_{c,\mathrm{gap}}\sim L^{-1}$, there is a ergodicity breaking transition such that a finite-dimensional manifold remains non-ergodic for $未< 未_{c,\mathrm{gap}}$. Computational power is lost at a much smaller disorder, $未_{c,\mathrm{comp}} \sim L^{-1/2}2^{-L/2}$. We comment on relevance to non-systematic noise in realistic quantum computers, including cold atom, trapped ion, and superconducting platforms. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.10344v1-abstract-full').style.display = 'none'; document.getElementById('2406.10344v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 11 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/2406.06063">arXiv:2406.06063</a> <span> [<a href="https://arxiv.org/pdf/2406.06063">pdf</a>, <a href="https://arxiv.org/format/2406.06063">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Computational Physics">physics.comp-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Enabling Large-Scale and High-Precision Fluid Simulations on Near-Term Quantum Computers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zhao-Yun Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+T">Teng-Yang Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+C">Chuang-Chao Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+L">Liang Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+M">Ming-Yang Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhuang%2C+X">Xi-Ning Zhuang</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+X">Xiao-Fan Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yun-Jie Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+T">Tai-Ping Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Y">Yong Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+L">Lei Du</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+L">Liang-Liang Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+H">Hai-Feng Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Tao%2C+H">Hao-Ran Tao</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+T">Tian-Le Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+X">Xiao-Yan Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Z">Ze-An Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+P">Peng Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+S">Sheng Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+R">Ren-Ze Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Jia%2C+Z">Zhi-Long Jia</a>, <a href="/search/quant-ph?searchtype=author&query=Kong%2C+W">Wei-Cheng Kong</a>, <a href="/search/quant-ph?searchtype=author&query=Dou%2C+M">Meng-Han Dou</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jun-Chao Wang</a> , et al. (7 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="2406.06063v3-abstract-short" style="display: inline;"> Quantum computational fluid dynamics (QCFD) offers a promising alternative to classical computational fluid dynamics (CFD) by leveraging quantum algorithms for higher efficiency. This paper introduces a comprehensive QCFD method, including an iterative method "Iterative-QLS" that suppresses error in quantum linear solver, and a subspace method to scale the solution to a larger size. We implement o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.06063v3-abstract-full').style.display = 'inline'; document.getElementById('2406.06063v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.06063v3-abstract-full" style="display: none;"> Quantum computational fluid dynamics (QCFD) offers a promising alternative to classical computational fluid dynamics (CFD) by leveraging quantum algorithms for higher efficiency. This paper introduces a comprehensive QCFD method, including an iterative method "Iterative-QLS" that suppresses error in quantum linear solver, and a subspace method to scale the solution to a larger size. We implement our method on a superconducting quantum computer, demonstrating successful simulations of steady Poiseuille flow and unsteady acoustic wave propagation. The Poiseuille flow simulation achieved a relative error of less than $0.2\%$, and the unsteady acoustic wave simulation solved a 5043-dimensional matrix. We emphasize the utilization of the quantum-classical hybrid approach in applications of near-term quantum computers. By adapting to quantum hardware constraints and offering scalable solutions for large-scale CFD problems, our method paves the way for practical applications of near-term quantum computers in computational science. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.06063v3-abstract-full').style.display = 'none'; document.getElementById('2406.06063v3-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 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 pages, 10 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/2406.03006">arXiv:2406.03006</a> <span> [<a href="https://arxiv.org/pdf/2406.03006">pdf</a>, <a href="https://arxiv.org/ps/2406.03006">ps</a>, <a href="https://arxiv.org/format/2406.03006">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="Data Structures and Algorithms">cs.DS</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optimization and Control">math.OC</span> </div> </div> <p class="title is-5 mathjax"> Quantum Algorithms and Lower Bounds for Finite-Sum Optimization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yexin Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chenyi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Fang%2C+C">Cong Fang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+L">Liwei Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tongyang Li</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.03006v1-abstract-short" style="display: inline;"> Finite-sum optimization has wide applications in machine learning, covering important problems such as support vector machines, regression, etc. In this paper, we initiate the study of solving finite-sum optimization problems by quantum computing. Specifically, let $f_1,\ldots,f_n\colon\mathbb{R}^d\to\mathbb{R}$ be $\ell$-smooth convex functions and $蠄\colon\mathbb{R}^d\to\mathbb{R}$ be a $渭$-stro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.03006v1-abstract-full').style.display = 'inline'; document.getElementById('2406.03006v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.03006v1-abstract-full" style="display: none;"> Finite-sum optimization has wide applications in machine learning, covering important problems such as support vector machines, regression, etc. In this paper, we initiate the study of solving finite-sum optimization problems by quantum computing. Specifically, let $f_1,\ldots,f_n\colon\mathbb{R}^d\to\mathbb{R}$ be $\ell$-smooth convex functions and $蠄\colon\mathbb{R}^d\to\mathbb{R}$ be a $渭$-strongly convex proximal function. The goal is to find an $蔚$-optimal point for $F(\mathbf{x})=\frac{1}{n}\sum_{i=1}^n f_i(\mathbf{x})+蠄(\mathbf{x})$. We give a quantum algorithm with complexity $\tilde{O}\big(n+\sqrt{d}+\sqrt{\ell/渭}\big(n^{1/3}d^{1/3}+n^{-2/3}d^{5/6}\big)\big)$, improving the classical tight bound $\tilde螛\big(n+\sqrt{n\ell/渭}\big)$. We also prove a quantum lower bound $\tilde惟(n+n^{3/4}(\ell/渭)^{1/4})$ when $d$ is large enough. Both our quantum upper and lower bounds can extend to the cases where $蠄$ is not necessarily strongly convex, or each $f_i$ is Lipschitz but not necessarily smooth. In addition, when $F$ is nonconvex, our quantum algorithm can find an $蔚$-critial point using $\tilde{O}(n+\ell(d^{1/3}n^{1/3}+\sqrt{d})/蔚^2)$ queries. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.03006v1-abstract-full').style.display = 'none'; document.getElementById('2406.03006v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">27 pages. To appear in the Forty-first International Conference on Machine Learning International Conference on Machine Learning (ICML 2024)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.20225">arXiv:2405.20225</a> <span> [<a href="https://arxiv.org/pdf/2405.20225">pdf</a>, <a href="https://arxiv.org/format/2405.20225">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"> Novel oracle constructions for quantum random access memory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Nagy%2C+%C3%81">脕kos Nagy</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Cindy 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="2405.20225v2-abstract-short" style="display: inline;"> We present new designs for quantum random access memory. More precisely, for each function, $f : \mathbb{F}_2^n \rightarrow \mathbb{F}_2^d$, we construct oracles, $\mathcal{O}_f$, with the property \begin{equation} \mathcal{O}_f \left| x \right\rangle_n \left| 0 \right\rangle_d = \left| x \right\rangle_n \left| f(x) \right\rangle_d. \end{equation} Our methods are based on the Walsh-Hadamard Tran… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.20225v2-abstract-full').style.display = 'inline'; document.getElementById('2405.20225v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.20225v2-abstract-full" style="display: none;"> We present new designs for quantum random access memory. More precisely, for each function, $f : \mathbb{F}_2^n \rightarrow \mathbb{F}_2^d$, we construct oracles, $\mathcal{O}_f$, with the property \begin{equation} \mathcal{O}_f \left| x \right\rangle_n \left| 0 \right\rangle_d = \left| x \right\rangle_n \left| f(x) \right\rangle_d. \end{equation} Our methods are based on the Walsh-Hadamard Transform of $f$, viewed as an integer valued function. In general, the complexity of our method scales with the sparsity of the Walsh-Hadamard Transform and not the sparsity of $f$, yielding more favorable constructions in cases such as binary optimization problems and function with low-degree Walsh-Hadamard Transforms. Furthermore, our design comes with a tuneable amount of ancillas that can trade depth for size. In the ancilla-free design, these oracles can be $蔚$-approximated so that the Clifford + $T$ depth is $O \left( \left( n + \log_2 \left( \tfrac{d}蔚 \right) \right) \mathcal{W}_f \right)$, where $\mathcal{W}_f$ is the number of nonzero components in the Walsh-Hadamard Transform. The depth of the shallowest version is $O \left( n + \log_2 \left( \tfrac{d}蔚 \right) \right)$, using $n + d \mathcal{W}_f$ qubit. The connectivity of these circuits is also only logarithmic in $\mathcal{W}_f$. As an application, we show that for boolean functions with low approximate degrees (as in the case of read-once formulas) the complexities of the corresponding QRAM oracles scale only as $2^{\widetilde{O} \left( \sqrt{n} \log_2 \left( n \right) \right)}$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.20225v2-abstract-full').style.display = 'none'; document.getElementById('2405.20225v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 1 figures. 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/2405.16970">arXiv:2405.16970</a> <span> [<a href="https://arxiv.org/pdf/2405.16970">pdf</a>, <a href="https://arxiv.org/ps/2405.16970">ps</a>, <a href="https://arxiv.org/format/2405.16970">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"> Memory-assisted measurement-device-independent quantum secret sharing </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Cheng Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Q">Qi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+W">Wei Zhong</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+M">Ming-Ming Du</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+S">Shu-Ting Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xi-Yun Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+A">An-Lei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+L">Lan Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Sheng%2C+Y">Yu-Bo Sheng</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.16970v1-abstract-short" style="display: inline;"> Measurement-device-independent quantum secret sharing (MDI-QSS) can eliminate all the security loopholes associated with imperfect measurement devices and greatly enhance QS's security under practical experimental condition. MDI-QSS requires each communication user to send single photon to the measurement party for the coincident measurement. However, the unsynchronization of the transmitted photo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.16970v1-abstract-full').style.display = 'inline'; document.getElementById('2405.16970v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.16970v1-abstract-full" style="display: none;"> Measurement-device-independent quantum secret sharing (MDI-QSS) can eliminate all the security loopholes associated with imperfect measurement devices and greatly enhance QS's security under practical experimental condition. MDI-QSS requires each communication user to send single photon to the measurement party for the coincident measurement. However, the unsynchronization of the transmitted photons greatly limits MDI-QSS's practical performance.In the paper, we propose a high-efficient quantum memory (QM)-assisted MDI-QSS protocol, which employs the QM-assisted synchronization of three heralded single-photon sources to efficiently generate three simultaneous single-photon states. The QM constructed with all-optical, polarization-insensitive storage loop has superior performance in terms of bandwidth, storage efficiency, and noise resistance, and is feasible under current experiment conditions. Combining with the decoy-state method, we perform the numerical simulation of the secure key rate in the symmetric model without considering the finite-size effect. The simulation results show that our QM-assisted MDI-QSS protocol exhibit largely improved secure key rate and maximal photon transmission distance compared with all existing MDI-QSS protocols without QM. Our protocol provides a promising way for implementing the high-efficient long-distance MDI-QSS in the near future. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.16970v1-abstract-full').style.display = 'none'; document.getElementById('2405.16970v1-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 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.16425">arXiv:2405.16425</a> <span> [<a href="https://arxiv.org/pdf/2405.16425">pdf</a>, <a href="https://arxiv.org/format/2405.16425">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"> Dipolar bosons in a twisted bilayer geometry </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chao Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+Z">Zhijie Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Capogrosso-Sansone%2C+B">Barbara Capogrosso-Sansone</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+Y">Youjin Deng</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.16425v1-abstract-short" style="display: inline;"> In recent years, twisted bilayer systems such as bilayer graphene have attracted a great deal of attention as the twist angle introduces a degree of freedom which can be used to non-trivially modify system properties. This idea has been picked up in the cold atom community, first with a theoretical proposal to simulate twisted bilayers in state-dependent optical lattices, and, more recently, with… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.16425v1-abstract-full').style.display = 'inline'; document.getElementById('2405.16425v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.16425v1-abstract-full" style="display: none;"> In recent years, twisted bilayer systems such as bilayer graphene have attracted a great deal of attention as the twist angle introduces a degree of freedom which can be used to non-trivially modify system properties. This idea has been picked up in the cold atom community, first with a theoretical proposal to simulate twisted bilayers in state-dependent optical lattices, and, more recently, with an experimental realization of twisted bilayers with bosonic atoms in two different spin states. In this manuscript, we theoretically investigate dipolar bosons in a twisted bilayer geometry. The interplay between dipolar interaction and the twist between the layers results in the emergence of quantum states not observed in the absence of twist. We study how system properties vary as we change the twist angle at fixed distance between the layers and fixed dipolar interaction. We find that at a twist angle $胃=0.1^{\circ}$, the observed quantum phases are consistent with those seen in the absence of twist angle, i.e. paired superfluid, paired supersolid, and paired solid phases. However, a slight increase in the twist angle to $胃=0.2^{\circ}$ disrupts these paired phases in favor of a phase separation between checkerboard solid and superfluid regions. Notably, at a twist angle of $胃=5.21^{\circ}$, the local occupation number follows the moir茅 pattern of the underlying moir茅 bilayers so that a periodic structure of insulating islands is formed. These insulating islands are surrounded by a superfluid. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.16425v1-abstract-full').style.display = 'none'; document.getElementById('2405.16425v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.12838">arXiv:2405.12838</a> <span> [<a href="https://arxiv.org/pdf/2405.12838">pdf</a>, <a href="https://arxiv.org/ps/2405.12838">ps</a>, <a href="https://arxiv.org/format/2405.12838">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="Computation">stat.CO</span> </div> </div> <p class="title is-5 mathjax"> Quantum Non-Identical Mean Estimation: Efficient Algorithms and Fundamental Limits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hu%2C+J">Jiachen Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tongyang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xinzhao Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Xue%2C+Y">Yecheng Xue</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chenyi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+H">Han Zhong</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.12838v1-abstract-short" style="display: inline;"> We systematically investigate quantum algorithms and lower bounds for mean estimation given query access to non-identically distributed samples. On the one hand, we give quantum mean estimators with quadratic quantum speed-up given samples from different bounded or sub-Gaussian random variables. On the other hand, we prove that, in general, it is impossible for any quantum algorithm to achieve qua… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.12838v1-abstract-full').style.display = 'inline'; document.getElementById('2405.12838v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.12838v1-abstract-full" style="display: none;"> We systematically investigate quantum algorithms and lower bounds for mean estimation given query access to non-identically distributed samples. On the one hand, we give quantum mean estimators with quadratic quantum speed-up given samples from different bounded or sub-Gaussian random variables. On the other hand, we prove that, in general, it is impossible for any quantum algorithm to achieve quadratic speed-up over the number of classical samples needed to estimate the mean $渭$, where the samples come from different random variables with mean close to $渭$. Technically, our quantum algorithms reduce bounded and sub-Gaussian random variables to the Bernoulli case, and use an uncomputation trick to overcome the challenge that direct amplitude estimation does not work with non-identical query access. Our quantum query lower bounds are established by simulating non-identical oracles by parallel oracles, and also by an adversarial method with non-identical oracles. Both results pave the way for proving quantum query lower bounds with non-identical oracles in general, which may be of independent interest. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.12838v1-abstract-full').style.display = 'none'; document.getElementById('2405.12838v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 pages, 0 figure. To appear in the 19th Theory of Quantum Computation, Communication and Cryptography (TQC 2024)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.15878">arXiv:2404.15878</a> <span> [<a href="https://arxiv.org/pdf/2404.15878">pdf</a>, <a href="https://arxiv.org/format/2404.15878">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="Fluid Dynamics">physics.flu-dyn</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s42005-024-01845-w">10.1038/s42005-024-01845-w <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Simulating unsteady fluid flows on a superconducting quantum processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Meng%2C+Z">Zhaoyuan Meng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+J">Jiarun Zhong</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+S">Shibo Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+K">Ke Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+J">Jiachen Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+F">Feitong Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xuhao Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yaozu Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanyu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+N">Ning Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zou%2C+Y">Yiren Zou</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+A">Aosai Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Cui%2C+Z">Zhengyi Cui</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+F">Fanhao Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Z">Zehang Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Z">Zitian Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+Z">Ziqi Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tingting Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+P">Pengfei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Xiong%2C+S">Shiying Xiong</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hekang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+Q">Qiujiang Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Zhen Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+C">Chao Song</a> , et al. (2 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="2404.15878v1-abstract-short" style="display: inline;"> Recent advancements of intermediate-scale quantum processors have triggered tremendous interest in the exploration of practical quantum advantage. The simulation of fluid dynamics, a highly challenging problem in classical physics but vital for practical applications, emerges as a good candidate for showing quantum utility. Here, we report an experiment on the digital simulation of unsteady flows,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.15878v1-abstract-full').style.display = 'inline'; document.getElementById('2404.15878v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.15878v1-abstract-full" style="display: none;"> Recent advancements of intermediate-scale quantum processors have triggered tremendous interest in the exploration of practical quantum advantage. The simulation of fluid dynamics, a highly challenging problem in classical physics but vital for practical applications, emerges as a good candidate for showing quantum utility. Here, we report an experiment on the digital simulation of unsteady flows, which consists of quantum encoding, evolution, and detection of flow states, with a superconducting quantum processor. The quantum algorithm is based on the Hamiltonian simulation using the hydrodynamic formulation of the Schr枚dinger equation. With the median fidelities of 99.97% and 99.67% for parallel single- and two-qubit gates respectively, we simulate the dynamics of a two-dimensional (2D) compressible diverging flow and a 2D decaying vortex with ten qubits. The experimental results well capture the temporal evolution of averaged density and momentum profiles, and qualitatively reproduce spatial flow fields with moderate noises. This work demonstrates the potential of quantum computing in simulating more complex flows, such as turbulence, for practical applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.15878v1-abstract-full').style.display = 'none'; document.getElementById('2404.15878v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.13297">arXiv:2404.13297</a> <span> [<a href="https://arxiv.org/pdf/2404.13297">pdf</a>, <a href="https://arxiv.org/format/2404.13297">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="Strongly Correlated Electrons">cond-mat.str-el</span> </div> </div> <p class="title is-5 mathjax"> Coalescing hardcore-boson condensate states with nonzero momentum </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C+H">C. H. Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+Z">Z. Song</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="2404.13297v2-abstract-short" style="display: inline;"> Exceptional points (EPs), as an exclusive feature of a non-Hermitian system, support coalescing states to be alternative stable state beyond the ground state. In this work, we explore the influence of non-Hermitian impurities on the dynamic formation of condensate states in one-, two-, and three-dimensional extended Bose-Hubbard systems with strong on-site interaction. Based on the solution for th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.13297v2-abstract-full').style.display = 'inline'; document.getElementById('2404.13297v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.13297v2-abstract-full" style="display: none;"> Exceptional points (EPs), as an exclusive feature of a non-Hermitian system, support coalescing states to be alternative stable state beyond the ground state. In this work, we explore the influence of non-Hermitian impurities on the dynamic formation of condensate states in one-, two-, and three-dimensional extended Bose-Hubbard systems with strong on-site interaction. Based on the solution for the hardcore limit, we show exactly that condensate modes with off-diagonal long-range order (ODLRO) can exist when certain system parameters satisfy specific matching conditions. Under open boundary conditions, the condensate states become coalescing states when the non-Hermitian $\mathcal{PT}$-symmetric boundary gives rise to the EPs. The fundamental mechanism behind this phenomenon is uncovered through analyzing the scattering dynamics of many-particle wavepackets at the non-Hermitian boundaries. The EP dynamics facilitate the dynamic generation of condensate states with non-zero momentum. To further substantiate the theoretical findings, numerical simulations are conducted. This study not only unveils the potential condensation of interacting bosons but also offers an approach for the engineering of condensate states. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.13297v2-abstract-full').style.display = 'none'; document.getElementById('2404.13297v2-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 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.13151">arXiv:2404.13151</a> <span> [<a href="https://arxiv.org/pdf/2404.13151">pdf</a>, <a href="https://arxiv.org/format/2404.13151">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 class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.132.233403">10.1103/PhysRevLett.132.233403 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of Momentum Space Josephson Effects </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Mukhopadhyay%2C+A">Annesh Mukhopadhyay</a>, <a href="/search/quant-ph?searchtype=author&query=Luo%2C+X">Xi-Wang Luo</a>, <a href="/search/quant-ph?searchtype=author&query=Schimelfenig%2C+C">Colby Schimelfenig</a>, <a href="/search/quant-ph?searchtype=author&query=Ome%2C+M+K+H">M. K. H. Ome</a>, <a href="/search/quant-ph?searchtype=author&query=Mossman%2C+S">Sean Mossman</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanwei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Engels%2C+P">Peter Engels</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="2404.13151v1-abstract-short" style="display: inline;"> The momentum space Josephson effect describes the supercurrent flow between weakly coupled Bose-Einstein condensates (BECs) at two discrete momentum states. Here, we experimentally observe this exotic phenomenon using a BEC with Raman-induced spin-orbit coupling, where the tunneling between two local band minima is implemented by the momentum kick of an additional optical lattice. A sudden quench… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.13151v1-abstract-full').style.display = 'inline'; document.getElementById('2404.13151v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.13151v1-abstract-full" style="display: none;"> The momentum space Josephson effect describes the supercurrent flow between weakly coupled Bose-Einstein condensates (BECs) at two discrete momentum states. Here, we experimentally observe this exotic phenomenon using a BEC with Raman-induced spin-orbit coupling, where the tunneling between two local band minima is implemented by the momentum kick of an additional optical lattice. A sudden quench of the Raman detuning induces coherent spin-momentum oscillations of the BEC, which is analogous to the a.c. Josephson effect. We observe both plasma and regular Josephson oscillations in different parameter regimes. The experimental results agree well with the theoretical model and numerical simulation, and showcase the important role of nonlinear interactions. We also show that the measurement of the Josephson plasma frequency gives the Bogoliubov zero quasimomentum gap, which determines the mass of the corresponding pseudo-Goldstone mode, a long-sought phenomenon in particle physics. The observation of momentum space Josephson physics offers an exciting platform for quantum simulation and sensing utilizing momentum states as a synthetic degree. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.13151v1-abstract-full').style.display = 'none'; document.getElementById('2404.13151v1-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 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">12 pages, 11 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/2404.10264">arXiv:2404.10264</a> <span> [<a href="https://arxiv.org/pdf/2404.10264">pdf</a>, <a href="https://arxiv.org/format/2404.10264">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Phenomenology">hep-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"> Calibration of the Cryogenic Measurement System of a Resonant Haloscope Cavity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=He%2C+D">Dong He</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+J">Jie Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+X">Xin Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Houston%2C+N">Nick Houston</a>, <a href="/search/quant-ph?searchtype=author&query=Ji%2C+Z">Zhongqing Ji</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+Y">Yirong Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chuang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+J">Jinmian Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tianjun Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+S">Shi-hang Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Niu%2C+J">Jia-Shu Niu</a>, <a href="/search/quant-ph?searchtype=author&query=Peng%2C+Z">Zhihui Peng</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+L">Liang Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+Z">Zheng Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jia Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wei%2C+P">Puxian Wei</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+L">Lina Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+Z">Zhongchen Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Q">Qiaoli Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+W">Wenxing Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+X">Xin Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+D">Dongning Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+R">Ruifeng Zheng</a> , et al. (1 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="2404.10264v1-abstract-short" style="display: inline;"> Possible light bosonic dark matter interactions with the Standard Model photon have been searched by microwave resonant cavities. In this paper, we demonstrate the cryogenic readout system calibration of a 7.138 GHz copper cavity with a loaded quality factor $Q_l=10^4$, operated at 22 mK temperature based on a dilution refrigerator. Our readout system consists of High Electron Mobility Transistors… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.10264v1-abstract-full').style.display = 'inline'; document.getElementById('2404.10264v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.10264v1-abstract-full" style="display: none;"> Possible light bosonic dark matter interactions with the Standard Model photon have been searched by microwave resonant cavities. In this paper, we demonstrate the cryogenic readout system calibration of a 7.138 GHz copper cavity with a loaded quality factor $Q_l=10^4$, operated at 22 mK temperature based on a dilution refrigerator. Our readout system consists of High Electron Mobility Transistors as cryogenic amplifiers at 4 K, plus room-temperature amplifiers and a spectrum analyzer for signal power detection. We test the system with a superconducting two-level system as a single-photon source in the microwave frequency regime and report an overall 95.6 dB system gain and -71.4 dB attenuation in the cavity's input channel. The effective noise temperature of the measurement system is 7.5 K. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.10264v1-abstract-full').style.display = 'none'; document.getElementById('2404.10264v1-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 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">7 pages, 5 figures, version to appear in CPC</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.10049">arXiv:2404.10049</a> <span> [<a href="https://arxiv.org/pdf/2404.10049">pdf</a>, <a href="https://arxiv.org/format/2404.10049">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="Materials Science">cond-mat.mtrl-sci</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="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.110.L121122">10.1103/PhysRevB.110.L121122 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Berry-dipole Semimetals </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhuang%2C+Z">Zheng-Yang Zhuang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chaoyi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xiao-Jiao Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Yan%2C+Z">Zhongbo Yan</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="2404.10049v1-abstract-short" style="display: inline;"> We introduce ''Berry-dipole semimetals'', whose band degeneracies are characterized by quantized Berry dipoles. Through a two-band model constructed by Hopf map, we reveal that the Berry-dipole semimetals display a multitude of salient properties distinct from other topological semimetals. On the boundary, we find that the first-order Berry-dipole semimetal harbors anomalous paired Fermi arcs with… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.10049v1-abstract-full').style.display = 'inline'; document.getElementById('2404.10049v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.10049v1-abstract-full" style="display: none;"> We introduce ''Berry-dipole semimetals'', whose band degeneracies are characterized by quantized Berry dipoles. Through a two-band model constructed by Hopf map, we reveal that the Berry-dipole semimetals display a multitude of salient properties distinct from other topological semimetals. On the boundary, we find that the first-order Berry-dipole semimetal harbors anomalous paired Fermi arcs with the same spin polarization, even though the layer Chern number is zero, and the second-order Berry-dipole semimetal hosts dispersionless hinge arcs. In the bulk, we find that the low-energy Berry-dipole Hamiltonian near the band node has a quadratic energy dispersion and peculiar Berry curvature, which give rise to rather unique characteristics in the intrinsic anomalous Hall effect, orbital magnetization and Landau levels. Our study shows that Berry-dipole semimetals are a class of topological gapless phases supporting rich intriguing physics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.10049v1-abstract-full').style.display = 'none'; document.getElementById('2404.10049v1-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 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">7+12 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/2404.03803">arXiv:2404.03803</a> <span> [<a href="https://arxiv.org/pdf/2404.03803">pdf</a>, <a href="https://arxiv.org/format/2404.03803">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="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Scaling of quantum Fisher information for quantum exceptional point sensors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+C">Chun-Hui Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+F">Fu Li</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+S">Shengwang Du</a>, <a href="/search/quant-ph?searchtype=author&query=Wen%2C+J">Jianming Wen</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+L">Lan Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanwei 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="2404.03803v1-abstract-short" style="display: inline;"> In recent years, significant progress has been made in utilizing the divergence of spectrum response rate at the exceptional point (EP) for sensing in classical systems, while the use and characterization of quantum EPs for sensing have been largely unexplored. For a quantum EP sensor, an important issue is the relation between the order of the quantum EP and the scaling of quantum Fisher informat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.03803v1-abstract-full').style.display = 'inline'; document.getElementById('2404.03803v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.03803v1-abstract-full" style="display: none;"> In recent years, significant progress has been made in utilizing the divergence of spectrum response rate at the exceptional point (EP) for sensing in classical systems, while the use and characterization of quantum EPs for sensing have been largely unexplored. For a quantum EP sensor, an important issue is the relation between the order of the quantum EP and the scaling of quantum Fisher information (QFI), an essential quantity for characterizing quantum sensors. Here we investigate multi-mode quadratic bosonic systems, which exhibit higher-order EP dynamics, but possess Hermitian Hamiltonians without Langevin noise, thus can be utilized for quantum sensing. We derive an exact analytic formula for the QFI, from which we establish a scaling relation between the QFI and the order of the EP. We apply the formula to study a three-mode EP sensor and a multi-mode bosonic Kitaev chain and show that the EP physics can significantly enhance the sensing sensitivity. Our work establishes the connection between two important fields: non-Hermitian EP dynamics and quantum sensing, and may find important applications in quantum information and quantum non-Hermitian physics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.03803v1-abstract-full').style.display = 'none'; document.getElementById('2404.03803v1-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, 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">18 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/2404.00091">arXiv:2404.00091</a> <span> [<a href="https://arxiv.org/pdf/2404.00091">pdf</a>, <a href="https://arxiv.org/format/2404.00091">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/10.1038/s41567-024-02529-6">10.1038/s41567-024-02529-6 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Non-Abelian braiding of Fibonacci anyons with a superconducting processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xu%2C+S">Shibo Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+Z">Zheng-Zhi Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+K">Ke Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hekang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Z">Zitian Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+H">Hang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+J">Jinfeng Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+X">Xu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+J">Jiachen Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yaozu Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanyu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+F">Feitong Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xuhao Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+A">Aosai Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+N">Ning Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zou%2C+Y">Yiren Zou</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+Z">Ziqi Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+F">Fanhao Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+J">Jiarun Zhong</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Z">Zehang Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+W">Weikang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+W">Wenjie Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+L">Li-Wei Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+Z">Zixuan Song</a> , et al. (7 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="2404.00091v1-abstract-short" style="display: inline;"> Non-Abelian topological orders offer an intriguing path towards fault-tolerant quantum computation, where information can be encoded and manipulated in a topologically protected manner immune to arbitrary local noises and perturbations. However, realizing non-Abelian topologically ordered states is notoriously challenging in both condensed matter and programmable quantum systems, and it was not un… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.00091v1-abstract-full').style.display = 'inline'; document.getElementById('2404.00091v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.00091v1-abstract-full" style="display: none;"> Non-Abelian topological orders offer an intriguing path towards fault-tolerant quantum computation, where information can be encoded and manipulated in a topologically protected manner immune to arbitrary local noises and perturbations. However, realizing non-Abelian topologically ordered states is notoriously challenging in both condensed matter and programmable quantum systems, and it was not until recently that signatures of non-Abelian statistics were observed through digital quantum simulation approaches. Despite these exciting progresses, none of them has demonstrated the appropriate type of topological orders and associated non-Abelian anyons whose braidings alone support universal quantum computation. Here, we report the realization of non-Abelian topologically ordered states of the Fibonacci string-net model and demonstrate braidings of Fibonacci anyons featuring universal computational power, with a superconducting quantum processor. We exploit efficient quantum circuits to prepare the desired states and verify their nontrivial topological nature by measuring the topological entanglement entropy. In addition, we create two pairs of Fibonacci anyons and demonstrate their fusion rule and non-Abelian braiding statistics by applying unitary gates on the underlying physical qubits. Our results establish a versatile digital approach to exploring exotic non-Abelian topological states and their associated braiding statistics with current noisy intermediate-scale quantum processors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.00091v1-abstract-full').style.display = 'none'; document.getElementById('2404.00091v1-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 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.16935">arXiv:2403.16935</a> <span> [<a href="https://arxiv.org/pdf/2403.16935">pdf</a>, <a href="https://arxiv.org/format/2403.16935">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"> Measuring Spectral Form Factor in Many-Body Chaotic and Localized Phases of Quantum Processors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Dong%2C+H">Hang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+P">Pengfei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Dag%2C+C+B">Ceren B. Dag</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+Y">Yu Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+N">Ning Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+J">Jinfeng Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+X">Xu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+J">Jiachen Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+S">Shibo Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+K">Ke Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yaozu Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chuanyu Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+F">Feitong Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xuhao Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+A">Aosai Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zou%2C+Y">Yiren Zou</a>, <a href="/search/quant-ph?searchtype=author&query=Tan%2C+Z">Ziqi Tan</a>, <a href="/search/quant-ph?searchtype=author&query=Cui%2C+Z">Zhengyi Cui</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Z">Zitian Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+F">Fanhao Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tingting Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhong%2C+J">Jiarun Zhong</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Z">Zehang Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hekang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Zhen Wang</a> , et al. (6 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="2403.16935v1-abstract-short" style="display: inline;"> The spectral form factor (SFF) captures universal spectral fluctuations as signatures of quantum chaos, and has been instrumental in advancing multiple frontiers of physics including the studies of black holes and quantum many-body systems. However, the measurement of SFF in many-body systems is challenging due to the difficulty in resolving level spacings that become exponentially small with incr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.16935v1-abstract-full').style.display = 'inline'; document.getElementById('2403.16935v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.16935v1-abstract-full" style="display: none;"> The spectral form factor (SFF) captures universal spectral fluctuations as signatures of quantum chaos, and has been instrumental in advancing multiple frontiers of physics including the studies of black holes and quantum many-body systems. However, the measurement of SFF in many-body systems is challenging due to the difficulty in resolving level spacings that become exponentially small with increasing system size. Here we experimentally measure the SFF to probe the presence or absence of chaos in quantum many-body systems using a superconducting quantum processor with a randomized measurement protocol. For a Floquet chaotic system, we observe signatures of spectral rigidity of random matrix theory in SFF given by the ramp-plateau behavior. For a Hamiltonian system, we utilize SFF to distinguish the quantum many-body chaotic phase and the prethermal many-body localization. We observe the dip-ramp-plateau behavior of random matrix theory in the chaotic phase, and contrast the scaling of the plateau time in system size between the many-body chaotic and localized phases. Furthermore, we probe the eigenstate statistics by measuring a generalization of the SFF, known as the partial SFF, and observe distinct behaviors in the purities of the reduced density matrix in the two phases. This work unveils a new way of extracting the universal signatures of many-body quantum chaos in quantum devices by probing the correlations in eigenenergies and eigenstates. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.16935v1-abstract-full').style.display = 'none'; document.getElementById('2403.16935v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">12 pages, 9 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/2403.16414">arXiv:2403.16414</a> <span> [<a href="https://arxiv.org/pdf/2403.16414">pdf</a>, <a href="https://arxiv.org/format/2403.16414">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="High Energy Physics - Phenomenology">hep-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"> Generation of $纬$-photons and pairs with transverse orbital angular momentum via spatiotemporal optical vortex pulse </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Cui-Wen Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+D">De-Sheng Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+B">Bai-Song Xie</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="2403.16414v1-abstract-short" style="display: inline;"> We present the generation of well-collimated $纬$-photons and pairs with extrinsic transverse orbital angular momentum (TOAM) through the head-on collision of an intense spatiotemporal optical vortex (STOV) pulse carrying intrinsic TOAM with a high-energy electron beam. It is found that the TOAM of STOV pulse remains almost unchanged, and the TOAM is conserved in the center-of-mass frame (CMF). Mor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.16414v1-abstract-full').style.display = 'inline'; document.getElementById('2403.16414v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.16414v1-abstract-full" style="display: none;"> We present the generation of well-collimated $纬$-photons and pairs with extrinsic transverse orbital angular momentum (TOAM) through the head-on collision of an intense spatiotemporal optical vortex (STOV) pulse carrying intrinsic TOAM with a high-energy electron beam. It is found that the TOAM of STOV pulse remains almost unchanged, and the TOAM is conserved in the center-of-mass frame (CMF). Moreover, there exhibits duality for particles TOAM in the CMF and laboratory frame (LF) when the initial location of high-energy electron beam is different. Furthermore, the TOAM of $纬$-photons in the CMF increases while that of positrons decreases as the topological charge of STOV pulse increases, whereas in the LF, the TOAM of both $纬$-photons and positrons decreases. And the result under the same pulse intensity is better than that under the same pulse energy. The increase in the initial energy of high-energy electrons leads to an enhancement of the TOAM for both $纬$-photons and positrons in both frames. $纬$-photons and electrons/positrons with TOAM as a new degree of freedom maybe have an extensive applications in optical communication, astrophysics and nanomaterials and so on. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.16414v1-abstract-full').style.display = 'none'; document.getElementById('2403.16414v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">18 pages, 9 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/2403.13503">arXiv:2403.13503</a> <span> [<a href="https://arxiv.org/pdf/2403.13503">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> </div> </div> <p class="title is-5 mathjax"> First Demonstration of 25位 x 10 Gb/s C+L Band Classical / DV-QKD Co-Existence Over Single Bidirectional Fiber Link </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Honz%2C+F">Florian Honz</a>, <a href="/search/quant-ph?searchtype=author&query=Prawits%2C+F">Florian Prawits</a>, <a href="/search/quant-ph?searchtype=author&query=Alia%2C+O">Obada Alia</a>, <a href="/search/quant-ph?searchtype=author&query=Sakr%2C+H">Hesham Sakr</a>, <a href="/search/quant-ph?searchtype=author&query=Bradley%2C+T">Thomas Bradley</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Cong Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Slav%C3%ADk%2C+R">Radan Slav铆k</a>, <a href="/search/quant-ph?searchtype=author&query=Poletti%2C+F">Francesco Poletti</a>, <a href="/search/quant-ph?searchtype=author&query=Kanellos%2C+G">George Kanellos</a>, <a href="/search/quant-ph?searchtype=author&query=Nejabati%2C+R">Reza Nejabati</a>, <a href="/search/quant-ph?searchtype=author&query=Walther%2C+P">Philip Walther</a>, <a href="/search/quant-ph?searchtype=author&query=Simeonidou%2C+D">Dimitra Simeonidou</a>, <a href="/search/quant-ph?searchtype=author&query=H%C3%BCbel%2C+H">Hannes H眉bel</a>, <a href="/search/quant-ph?searchtype=author&query=Schrenk%2C+B">Bernhard Schrenk</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="2403.13503v1-abstract-short" style="display: inline;"> As quantum key distribution has reached the maturity level for practical deployment, questions about the co-integration with existing classical communication systems are of utmost importance. To this end we demonstrate how the co-propagation of classical and quantum signals can benefit from the development of novel hollow-core fibers. We demonstrate a secure key rate of 330 bit/s for a quantum cha… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.13503v1-abstract-full').style.display = 'inline'; document.getElementById('2403.13503v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.13503v1-abstract-full" style="display: none;"> As quantum key distribution has reached the maturity level for practical deployment, questions about the co-integration with existing classical communication systems are of utmost importance. To this end we demonstrate how the co-propagation of classical and quantum signals can benefit from the development of novel hollow-core fibers. We demonstrate a secure key rate of 330 bit/s for a quantum channel at 1538 nm in the presence of 25 x 10 Gb/s classical channels, transmitted at an aggregated launch power of 12 dBm, spanning over the C+L-band in the same hollow-core fiber link. Furthermore, we show the co-integration of the classical key-distillation channel onto this fiber link, turning it into a bidirectional fiber link and thereby mitigating the need for multiple fibers. We believe this to be an important step towards the deployment and integration of hollow-core fibers together with DV-QKD for the inherently secure telecom network of the future. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.13503v1-abstract-full').style.display = 'none'; document.getElementById('2403.13503v1-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.10294">arXiv:2403.10294</a> <span> [<a href="https://arxiv.org/pdf/2403.10294">pdf</a>, <a href="https://arxiv.org/format/2403.10294">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.522384">10.1364/OE.522384 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental demonstration of improved reference-frame-independent quantum key distribution over 175km </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Tian%2C+Z">Zhiyu Tian</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Z">Ziran Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+R">Rong Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chunmei Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+S">Shihai Sun</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="2403.10294v1-abstract-short" style="display: inline;"> Reference-frame-independent (RFI) quantum key distribution (QKD) presents promising advantages, especially for mobile-platform-based implementations, as it eliminates the need for active reference frame calibration. While RFI-QKD has been explored in various studies, limitations in key rate and distance persist due to finite data collection. In this study, we experimentally demonstrate an improved… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.10294v1-abstract-full').style.display = 'inline'; document.getElementById('2403.10294v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.10294v1-abstract-full" style="display: none;"> Reference-frame-independent (RFI) quantum key distribution (QKD) presents promising advantages, especially for mobile-platform-based implementations, as it eliminates the need for active reference frame calibration. While RFI-QKD has been explored in various studies, limitations in key rate and distance persist due to finite data collection. In this study, we experimentally demonstrate an improved RFI-QKD protocol proposed by Zhu \textit{et al.} [Opt. Lett. 47, 4219 (2022)], featuring a statistical quantity for bounding information leaked to Eve that exhibits more insensitivity to statistical fluctuations and more robustness to variations in the reference frame. Taking into account finite-size considerations and potential general attacks, RFI-QKD is implemented over a distance of 175 \si{\kilo\meter} in this work. We believe that our study extends the communication distance achievable by RFI-QKD, thereby constituting a notable advancement for its practical application. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.10294v1-abstract-full').style.display = 'none'; document.getElementById('2403.10294v1-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 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">9 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Optics Express, Vol.32, No.13/17, 22460 (2024) </p> </li> </ol> <nav class="pagination is-small 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