Search | arXiv e-print repository

<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"/> <meta name="viewport" content="width=device-width, initial-scale=1"/>  <link rel="apple-touch-icon" sizes="180x180" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/apple-touch-icon.png"> <link rel="icon" type="image/png" sizes="32x32" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/favicon-32x32.png"> <link rel="icon" type="image/png" sizes="16x16" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/favicon-16x16.png"> <link rel="manifest" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/site.webmanifest"> <link rel="mask-icon" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/safari-pinned-tab.svg" color="#b31b1b"> <link rel="shortcut icon" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/favicon.ico"> <meta name="msapplication-TileColor" content="#b31b1b"> <meta name="msapplication-config" content="images/icons/browserconfig.xml"> <meta name="theme-color" content="#b31b1b">  <title>Search | arXiv e-print repository</title> <script defer src="https://static.arxiv.org/static/base/1.0.0a5/fontawesome-free-5.11.2-web/js/all.js"></script> <link rel="stylesheet" href="https://static.arxiv.org/static/base/1.0.0a5/css/arxivstyle.css" /> <script type="text/x-mathjax-config"> MathJax.Hub.Config({ messageStyle: "none", extensions: ["tex2jax.js"], jax: ["input/TeX", "output/HTML-CSS"], tex2jax: { inlineMath: [ ['$','$'], ["\$","\$"] ], displayMath: [ ['$$','$$'], ["\\[","\\]"] ], processEscapes: true, ignoreClass: '.*', processClass: 'mathjax.*' }, TeX: { extensions: ["AMSmath.js", "AMSsymbols.js", "noErrors.js"], noErrors: { inlineDelimiters: ["$","$"], multiLine: false, style: { "font-size": "normal", "border": "" } } }, "HTML-CSS": { availableFonts: ["TeX"] } }); </script> <script src='//static.arxiv.org/MathJax-2.7.3/MathJax.js'></script> <script src="https://static.arxiv.org/static/base/1.0.0a5/js/notification.js"></script> <link rel="stylesheet" href="https://static.arxiv.org/static/search/0.5.6/css/bulma-tooltip.min.css" /> <link rel="stylesheet" href="https://static.arxiv.org/static/search/0.5.6/css/search.css" /> <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha256-k2WSCIexGzOj3Euiig+TlR8gA0EmPjuc79OEeY5L45g=" crossorigin="anonymous"></script> <script src="https://static.arxiv.org/static/search/0.5.6/js/fieldset.js"></script> <style> radio#cf-customfield_11400 { display: none; } </style> </head> <body> <header><a href="#main-container" class="is-sr-only">Skip to main content</a>  <div class="attribution level is-marginless" role="banner"> <div class="level-left"> <a class="level-item" href="https://cornell.edu/"><img src="https://static.arxiv.org/static/base/1.0.0a5/images/cornell-reduced-white-SMALL.svg" alt="Cornell University" width="200" aria-label="logo" /></a> </div> <div class="level-right is-marginless"><p class="sponsors level-item is-marginless"><span id="support-ack-url">We gratefully acknowledge support from<br /> the Simons Foundation, <a href="https://info.arxiv.org/about/ourmembers.html">member institutions</a>, and all contributors. <a href="https://info.arxiv.org/about/donate.html">Donate</a></span></p></div> </div>  <div class="identity level is-marginless"> <div class="level-left"> <div class="level-item"> <a class="arxiv" href="https://arxiv.org/" aria-label="arxiv-logo"> <img src="https://static.arxiv.org/static/base/1.0.0a5/images/arxiv-logo-one-color-white.svg" aria-label="logo" alt="arxiv logo" width="85" style="width:85px;"/> </a> </div> </div> <div class="search-block level-right"> <form class="level-item mini-search" method="GET" action="https://arxiv.org/search"> <div class="field has-addons"> <div class="control"> <input class="input is-small" type="text" name="query" placeholder="Search..." aria-label="Search term or terms" /> <p class="help"><a href="https://info.arxiv.org/help">Help</a> | <a href="https://arxiv.org/search/advanced">Advanced Search</a></p> </div> <div class="control"> <div class="select is-small"> <select name="searchtype" aria-label="Field to search"> <option value="all" selected="selected">All fields</option> <option value="title">Title</option> <option value="author">Author</option> <option value="abstract">Abstract</option> <option value="comments">Comments</option> <option value="journal_ref">Journal reference</option> <option value="acm_class">ACM classification</option> <option value="msc_class">MSC classification</option> <option value="report_num">Report number</option> <option value="paper_id">arXiv identifier</option> <option value="doi">DOI</option> <option value="orcid">ORCID</option> <option value="author_id">arXiv author ID</option> <option value="help">Help pages</option> <option value="full_text">Full text</option> </select> </div> </div> <input type="hidden" name="source" value="header"> <button class="button is-small is-cul-darker">Search</button> </div> </form> </div> </div>  <div class="container"> <div class="user-tools is-size-7 has-text-right has-text-weight-bold" role="navigation" aria-label="User menu"> <a href="https://arxiv.org/login">Login</a> </div> </div> </header> <main class="container" id="main-container"> <div class="level is-marginless"> <div class="level-left"> <h1 class="title is-clearfix"> Showing 1–45 of 45 results for author: <span class="mathjax">Zhu, Q</span> </h1> </div> <div class="level-right is-hidden-mobile">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> <div class="content"> <form method="GET" action="/search/quant-ph" aria-role="search"> Searching in archive <strong>quant-ph</strong>. <a href="/search/?searchtype=author&query=Zhu%2C+Q">Search in all archives.</a> <div class="field has-addons-tablet"> <div class="control is-expanded"> <label for="query" class="hidden-label">Search term or terms</label> <input class="input is-medium" id="query" name="query" placeholder="Search term..." type="text" value="Zhu, Q"> </div> <div class="select control is-medium"> <label class="is-hidden" for="searchtype">Field</label> <select class="is-medium" id="searchtype" name="searchtype"><option value="all">All fields</option><option value="title">Title</option><option selected value="author">Author(s)</option><option value="abstract">Abstract</option><option value="comments">Comments</option><option value="journal_ref">Journal reference</option><option value="acm_class">ACM classification</option><option value="msc_class">MSC classification</option><option value="report_num">Report number</option><option value="paper_id">arXiv identifier</option><option value="doi">DOI</option><option value="orcid">ORCID</option><option value="license">License (URI)</option><option value="author_id">arXiv author ID</option><option value="help">Help pages</option><option value="full_text">Full text</option></select> </div> <div class="control"> <button class="button is-link is-medium">Search</button> </div> </div> <div class="field"> <div class="control is-size-7"> <label class="radio"> <input checked id="abstracts-0" name="abstracts" type="radio" value="show"> Show abstracts </label> <label class="radio"> <input id="abstracts-1" name="abstracts" type="radio" value="hide"> Hide abstracts </label> </div> </div> <div class="is-clearfix" style="height: 2.5em"> <div class="is-pulled-right"> <a href="/search/advanced?terms-0-term=Zhu%2C+Q&terms-0-field=author&size=50&order=-announced_date_first">Advanced Search</a> </div> </div> <input type="hidden" name="order" value="-announced_date_first"> <input type="hidden" name="size" value="50"> </form> <div class="level breathe-horizontal"> <div class="level-left"> <form method="GET" action="/search/"> <div style="display: none;"> <select id="searchtype" name="searchtype"><option value="all">All fields</option><option value="title">Title</option><option selected value="author">Author(s)</option><option value="abstract">Abstract</option><option value="comments">Comments</option><option value="journal_ref">Journal reference</option><option value="acm_class">ACM classification</option><option value="msc_class">MSC classification</option><option value="report_num">Report number</option><option value="paper_id">arXiv identifier</option><option value="doi">DOI</option><option value="orcid">ORCID</option><option value="license">License (URI)</option><option value="author_id">arXiv author ID</option><option value="help">Help pages</option><option value="full_text">Full text</option></select> <input id="query" name="query" type="text" value="Zhu, Q"> <ul id="abstracts"><li><input checked id="abstracts-0" name="abstracts" type="radio" value="show"> <label for="abstracts-0">Show abstracts</label></li><li><input id="abstracts-1" name="abstracts" type="radio" value="hide"> <label for="abstracts-1">Hide abstracts</label></li></ul> </div> <div class="box field is-grouped is-grouped-multiline level-item"> <div class="control"> <span class="select is-small"> <select id="size" name="size"><option value="25">25</option><option selected value="50">50</option><option value="100">100</option><option value="200">200</option></select> </span> <label for="size">results per page</label>. </div> <div class="control"> <label for="order">Sort results by</label> <span class="select is-small"> <select id="order" name="order"><option selected value="-announced_date_first">Announcement date (newest first)</option><option value="announced_date_first">Announcement date (oldest first)</option><option value="-submitted_date">Submission date (newest first)</option><option value="submitted_date">Submission date (oldest first)</option><option value="">Relevance</option></select> </span> </div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.23560">arXiv:2410.23560</a> <span> [<a href="https://arxiv.org/pdf/2410.23560">pdf</a>, <a href="https://arxiv.org/format/2410.23560">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"> Untrained Filtering with Trained Focusing for Superior Quantum Architecture Search </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yu%2C+L">Lian-Hui Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xiao-Yu Li</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+G">Geng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qin-Sheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hui Li</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+G">Guo-Wu Yang</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="2410.23560v2-abstract-short" style="display: inline;"> Quantum architecture search (QAS) represents a fundamental challenge in quantum machine learning. Unlike previous methods that treat it as a static search process, from a perspective on QAS as an item retrieval task in vast search space, we decompose the search process into dynamic alternating phases of coarse and fine-grained knowledge learning. We propose quantum untrained-explored synergistic t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.23560v2-abstract-full').style.display = 'inline'; document.getElementById('2410.23560v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.23560v2-abstract-full" style="display: none;"> Quantum architecture search (QAS) represents a fundamental challenge in quantum machine learning. Unlike previous methods that treat it as a static search process, from a perspective on QAS as an item retrieval task in vast search space, we decompose the search process into dynamic alternating phases of coarse and fine-grained knowledge learning. We propose quantum untrained-explored synergistic trained architecture (QUEST-A),a framework through coarse-grained untrained filtering for rapid search space reduction and fine-grained trained focusing for precise space refinement in progressive QAS. QUEST-A develops an evolutionary mechanism with knowledge accumulation and reuse to enhance multi-level knowledge transfer in architecture searching. Experiments demonstrate QUEST-A's superiority over existing methods: enhancing model expressivity in signal representation, maintaining high performance across varying complexities in image classification, and achieving order-of-magnitude precision improvements in variational quantum eigensolver tasks, providing a transferable methodology for QAS. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.23560v2-abstract-full').style.display = 'none'; document.getElementById('2410.23560v2-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">v1</span> submitted 30 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.21415">arXiv:2407.21415</a> <span> [<a href="https://arxiv.org/pdf/2407.21415">pdf</a>, <a href="https://arxiv.org/format/2407.21415">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"> In situ Qubit Frequency Tuning Circuit for Scalable Superconducting Quantum Computing: Scheme and Experiment </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+L">Lei Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Yan%2C+Z">Zhiguang Yan</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+T">Tao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+C">Chenyin Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+T">Tianzuo Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+T">Tao Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Yan%2C+K">Kai Yan</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yuan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+Y">Yisen Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yuhuai Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+G">Gang Wu</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="2407.21415v1-abstract-short" style="display: inline;"> Frequency tunable qubit plays a significant role for scalable superconducting quantum processors. The state-of-the-art room-temperature electronics for tuning qubit frequency suffers from unscalable limit, such as heating problem, linear growth of control cables, etc. Here we propose a scalable scheme to tune the qubit frequency by using in situ superconducting circuit, which is based on radio fre… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.21415v1-abstract-full').style.display = 'inline'; document.getElementById('2407.21415v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.21415v1-abstract-full" style="display: none;"> Frequency tunable qubit plays a significant role for scalable superconducting quantum processors. The state-of-the-art room-temperature electronics for tuning qubit frequency suffers from unscalable limit, such as heating problem, linear growth of control cables, etc. Here we propose a scalable scheme to tune the qubit frequency by using in situ superconducting circuit, which is based on radio frequency superconducting quantum interference device (rf-SQUID). We demonstrate both theoretically and experimentally that the qubit frequency could be modulated by inputting several single pulses into rf-SQUID. Compared with the traditional scheme, our scheme not only solves the heating problem, but also provides the potential to exponentially reduce the number of cables inside the dilute refrigerator and the room-temperature electronics resource for tuning qubit frequency, which is achieved by a time-division-multiplex (TDM) scheme combining rf-SQUID with switch arrays. With such TDM scheme, the number of cables could be reduced from the usual $\sim 3n$ to $\sim \log_2{(3n)} + 1$ for two-dimensional quantum processors comprising $n$ qubits and $\sim 2n$ couplers. Our work paves the way for large-scale control of superconducting quantum processor. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.21415v1-abstract-full').style.display = 'none'; document.getElementById('2407.21415v1-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 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">9 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/2405.06888">arXiv:2405.06888</a> <span> [<a href="https://arxiv.org/pdf/2405.06888">pdf</a>, <a href="https://arxiv.org/format/2405.06888">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"> The Algorithm for Solving Quantum Linear Systems of Equations With Coherent Superposition and Its Extended Applications </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xia%2C+Q">Qiqing Xia</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qianru Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+H">Huiqin Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+L">Li Yang</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="2405.06888v1-abstract-short" style="display: inline;"> Many quantum algorithms for attacking symmetric cryptography involve the rank problem of quantum linear equations. In this paper, we first propose two quantum algorithms for solving quantum linear systems of equations with coherent superposition and construct their specific quantum circuits. Unlike previous related works, our quantum algorithms are universal. Specifically, the two quantum algorith… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.06888v1-abstract-full').style.display = 'inline'; document.getElementById('2405.06888v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.06888v1-abstract-full" style="display: none;"> Many quantum algorithms for attacking symmetric cryptography involve the rank problem of quantum linear equations. In this paper, we first propose two quantum algorithms for solving quantum linear systems of equations with coherent superposition and construct their specific quantum circuits. Unlike previous related works, our quantum algorithms are universal. Specifically, the two quantum algorithms can both compute the rank and general solution by one measurement. The difference between them is whether the data register containing the quantum coefficient matrix can be disentangled with other registers and keep the data qubits unchanged. On this basis, we apply the two quantum algorithms as a subroutine to parallel Simon's algorithm (with multiple periods), Grover Meets Simon algorithm, and Alg-PolyQ2 algorithm, respectively. Afterwards, we construct a quantum classifier within Grover Meets Simon algorithm and the test oracle within Alg-PolyQ2 algorithm in detail, including their respective quantum circuits. To our knowledge, no such specific analysis has been done before. We rigorously analyze the success probability of those algorithms to ensure that the success probability based on the proposed quantum algorithms will not be lower than that of those original algorithms. Finally, we discuss the lower bound of the number of CNOT gates for solving quantum linear systems of equations with coherent superposition, and our quantum algorithms reach the optimum in terms of minimizing the number of CNOT gates. Furthermore, our analysis indicates that the proposed algorithms are mainly suitable for conducting attacks against lightweight symmetric ciphers, within the effective working time of an ion trap quantum computer. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.06888v1-abstract-full').style.display = 'none'; document.getElementById('2405.06888v1-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 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.05481">arXiv:2405.05481</a> <span> [<a href="https://arxiv.org/pdf/2405.05481">pdf</a>, <a href="https://arxiv.org/format/2405.05481">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"> Achieving millisecond coherence fluxonium through overlap Josephson junctions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+F">Fei Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+K">Kannan Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhan%2C+H">Huijuan Zhan</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+L">Lu Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+F">Feng Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+H">Hantao Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hao Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Bai%2C+Y">Yang Bai</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+F">Feng Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Chang%2C+X">Xu Chang</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+R">Ran Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+X">Xun Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+G">Guicheng Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+L">Lijuan Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+R">Ruizi Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Ji%2C+H">Honghong Ji</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+X">Xizheng Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Mao%2C+L">Liyong Mao</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+Z">Zhijun Song</a>, <a href="/search/quant-ph?searchtype=author&query=Tang%2C+C">Chengchun Tang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hongcheng Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+T">Tenghui Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Ziang Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Xia%2C+T">Tian Xia</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+H">Hongxin Xu</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="2405.05481v1-abstract-short" style="display: inline;"> Fluxonium qubits are recognized for their high coherence times and high operation fidelities, attributed to their unique design incorporating over 100 Josephson junctions per superconducting loop. However, this complexity poses significant fabrication challenges, particularly in achieving high yield and junction uniformity with traditional methods. Here, we introduce an overlap process for Josephs… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.05481v1-abstract-full').style.display = 'inline'; document.getElementById('2405.05481v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.05481v1-abstract-full" style="display: none;"> Fluxonium qubits are recognized for their high coherence times and high operation fidelities, attributed to their unique design incorporating over 100 Josephson junctions per superconducting loop. However, this complexity poses significant fabrication challenges, particularly in achieving high yield and junction uniformity with traditional methods. Here, we introduce an overlap process for Josephson junction fabrication that achieves nearly 100% yield and maintains uniformity across a 2-inch wafer with less than 5% variation for the phase slip junction and less than 2% for the junction array. Our compact junction array design facilitates fluxonium qubits with energy relaxation times exceeding 1 millisecond at the flux frustration point, demonstrating consistency with state-of-the-art dielectric loss tangents and flux noise across multiple devices. This work suggests the scalability of high coherence fluxonium processors using CMOS-compatible processes, marking a significant step towards practical quantum computing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.05481v1-abstract-full').style.display = 'none'; document.getElementById('2405.05481v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.02028">arXiv:2404.02028</a> <span> [<a href="https://arxiv.org/pdf/2404.02028">pdf</a>, <a href="https://arxiv.org/format/2404.02028">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"> QUSL: Quantum Unsupervised Image Similarity Learning with Enhanced Performance </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yu%2C+L">Lian-Hui Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xiao-Yu Li</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+G">Geng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qin-Sheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hui Li</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+G">Guo-Wu Yang</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="2404.02028v4-abstract-short" style="display: inline;"> Leveraging quantum properties to enhance complex learning tasks has been proven feasible, with excellent recent achievements in the field of unsupervised learning. However, current quantum schemes neglect adaptive adjustments for unsupervised task scenarios. This work proposes a novel quantum unsupervised similarity learning method, QUSL. Firstly, QUSL uses similarity triplets for unsupervised lea… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.02028v4-abstract-full').style.display = 'inline'; document.getElementById('2404.02028v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.02028v4-abstract-full" style="display: none;"> Leveraging quantum properties to enhance complex learning tasks has been proven feasible, with excellent recent achievements in the field of unsupervised learning. However, current quantum schemes neglect adaptive adjustments for unsupervised task scenarios. This work proposes a novel quantum unsupervised similarity learning method, QUSL. Firstly, QUSL uses similarity triplets for unsupervised learning, generating positive samples by perturbing anchor images, achieving a learning process independent of classical algorithms. Subsequently, combining the feature interweaving of triplets, QUSL employs metaheuristic algorithms to systematically explore high-performance mapping processes, obtaining quantum circuit architectures more suitable for unsupervised image similarity tasks. Ultimately, QUSL realizes feature learning with lower quantum resource costs. Comprehensive numerical simulations and experiments on quantum computers demonstrate that QUSL outperforms state-of-the-art quantum methods. QUSL achieves over 50% reduction in critical quantum resource utilization. QUSL improves similarity detection correlation by up to 19.5% across multiple datasets, exhibiting robustness in NISQ environments. While using fewer quantum resources, QUSL shows potential for large-scale unsupervised tasks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.02028v4-abstract-full').style.display = 'none'; document.getElementById('2404.02028v4-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">v1</span> submitted 2 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/2308.16040">arXiv:2308.16040</a> <span> [<a href="https://arxiv.org/pdf/2308.16040">pdf</a>, <a href="https://arxiv.org/format/2308.16040">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"> Native approach to controlled-Z gates in inductively coupled fluxonium qubits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Ma%2C+X">Xizheng Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+G">Gengyan Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+F">Feng Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+F">Feng Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Chang%2C+X">Xu Chang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+J">Jianjun Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hao Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+R">Ran Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+X">Xun Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+L">Lijuan Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Ji%2C+H">Honghong Ji</a>, <a href="/search/quant-ph?searchtype=author&query=Ku%2C+H">Hsiang-Sheng Ku</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+K">Kannan Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+L">Lu Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Mao%2C+L">Liyong Mao</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+Z">Zhijun Song</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+H">Hantao Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Tang%2C+C">Chengchun Tang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+F">Fei Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hongcheng Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+T">Tenghui Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Xia%2C+T">Tian Xia</a>, <a href="/search/quant-ph?searchtype=author&query=Ying%2C+M">Make Ying</a>, <a href="/search/quant-ph?searchtype=author&query=Zhan%2C+H">Huijuan Zhan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+T">Tao Zhou</a> , et al. (5 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.16040v1-abstract-short" style="display: inline;"> The fluxonium qubits have emerged as a promising platform for gate-based quantum information processing. However, their extraordinary protection against charge fluctuations comes at a cost: when coupled capacitively, the qubit-qubit interactions are restricted to XX-interactions. Consequently, effective XX- or XZ-interactions are only constructed either by temporarily populating higher-energy stat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.16040v1-abstract-full').style.display = 'inline'; document.getElementById('2308.16040v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.16040v1-abstract-full" style="display: none;"> The fluxonium qubits have emerged as a promising platform for gate-based quantum information processing. However, their extraordinary protection against charge fluctuations comes at a cost: when coupled capacitively, the qubit-qubit interactions are restricted to XX-interactions. Consequently, effective XX- or XZ-interactions are only constructed either by temporarily populating higher-energy states, or by exploiting perturbative effects under microwave driving. Instead, we propose and demonstrate an inductive coupling scheme, which offers a wide selection of native qubit-qubit interactions for fluxonium. In particular, we leverage a built-in, flux-controlled ZZ-interaction to perform qubit entanglement. To combat the increased flux-noise-induced dephasing away from the flux-insensitive position, we use a continuous version of the dynamical decoupling scheme to perform noise filtering. Combining these, we demonstrate a 20 ns controlled-Z (CZ) gate with a mean fidelity of 99.53%. More than confirming the efficacy of our gate scheme, this high-fidelity result also reveals a promising but rarely explored parameter space uniquely suitable for gate operations between fluxonium qubits. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.16040v1-abstract-full').style.display = 'none'; document.getElementById('2308.16040v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.08640">arXiv:2307.08640</a> <span> [<a href="https://arxiv.org/pdf/2307.08640">pdf</a>, <a href="https://arxiv.org/format/2307.08640">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/10.22331/q-2024-01-24-1232">10.22331/q-2024-01-24-1232 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A new quantum machine learning algorithm: split hidden quantum Markov model inspired by quantum conditional master equation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xiao-Yu Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qin-Sheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+Y">Yong Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+H">Hao Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+G">Guo-Wu Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+L">Lian-Hui Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+G">Geng Chen</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="2307.08640v7-abstract-short" style="display: inline;"> The Hidden Quantum Markov Model (HQMM) has significant potential for analyzing time-series data and studying stochastic processes in the quantum domain as an upgrading option with potential advantages over classical Markov models. In this paper, we introduced the split HQMM (SHQMM) for implementing the hidden quantum Markov process, utilizing the conditional master equation with a fine balance con… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.08640v7-abstract-full').style.display = 'inline'; document.getElementById('2307.08640v7-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.08640v7-abstract-full" style="display: none;"> The Hidden Quantum Markov Model (HQMM) has significant potential for analyzing time-series data and studying stochastic processes in the quantum domain as an upgrading option with potential advantages over classical Markov models. In this paper, we introduced the split HQMM (SHQMM) for implementing the hidden quantum Markov process, utilizing the conditional master equation with a fine balance condition to demonstrate the interconnections among the internal states of the quantum system. The experimental results suggest that our model outperforms previous models in terms of scope of applications and robustness. Additionally, we establish a new learning algorithm to solve parameters in HQMM by relating the quantum conditional master equation to the HQMM. Finally, our study provides clear evidence that the quantum transport system can be considered a physical representation of HQMM. The SHQMM with accompanying algorithms present a novel method to analyze quantum systems and time series grounded in physical implementation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.08640v7-abstract-full').style.display = 'none'; document.getElementById('2307.08640v7-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Quantum 8, 1232 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.15972">arXiv:2305.15972</a> <span> [<a href="https://arxiv.org/pdf/2305.15972">pdf</a>, <a href="https://arxiv.org/format/2305.15972">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"> Logical Magic State Preparation with Fidelity Beyond the Distillation Threshold on a Superconducting Quantum Processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=He%2C+T">Tan He</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Wei%2C+Z">Zuolin Wei</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yiming Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+D">Dachao Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Guan%2C+H">Huijie Guan</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chung%2C+T">Tung-Hsun Chung</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+D">Daojin Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Cheng Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Han%2C+L">Lianchen Han</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+N">Na Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yuan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a> , et al. (13 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="2305.15972v2-abstract-short" style="display: inline;"> Fault-tolerant quantum computing based on surface code has emerged as an attractive candidate for practical large-scale quantum computers to achieve robust noise resistance. To achieve universality, magic states preparation is a commonly approach for introducing non-Clifford gates. Here, we present a hardware-efficient and scalable protocol for arbitrary logical state preparation for the rotated s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.15972v2-abstract-full').style.display = 'inline'; document.getElementById('2305.15972v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.15972v2-abstract-full" style="display: none;"> Fault-tolerant quantum computing based on surface code has emerged as an attractive candidate for practical large-scale quantum computers to achieve robust noise resistance. To achieve universality, magic states preparation is a commonly approach for introducing non-Clifford gates. Here, we present a hardware-efficient and scalable protocol for arbitrary logical state preparation for the rotated surface code, and further experimentally implement it on the \textit{Zuchongzhi} 2.1 superconducting quantum processor. An average of \hhl{$0.8983 \pm 0.0002$} logical fidelity at different logical states with distance-three is achieved, \hhl{taking into account both state preparation and measurement errors.} In particular, \hhl{the magic states $|A^{蟺/4}\rangle_L$, $|H\rangle_L$, and $|T\rangle_L$ are prepared non-destructively with logical fidelities of $0.8771 \pm 0.0009 $, $0.9090 \pm 0.0009 $, and $0.8890 \pm 0.0010$, respectively, which are higher than the state distillation protocol threshold, 0.859 (for H-type magic state) and 0.827 (for T -type magic state).} Our work provides a viable and efficient avenue for generating high-fidelity raw logical magic states, which is essential for realizing non-Clifford logical gates in the surface code. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.15972v2-abstract-full').style.display = 'none'; document.getElementById('2305.15972v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">In this version, we do not employ readout error mitigation strategies (in the previous version, we use readout transition matrix to mitigate the measurement error) to remove measurement errors because we believe it provides a more predictive assessment of the actual fidelity when generating and consuming magic states for a non-Clifford gate, as consuming the state involves measurement</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.08227">arXiv:2304.08227</a> <span> [<a href="https://arxiv.org/pdf/2304.08227">pdf</a>, <a href="https://arxiv.org/format/2304.08227">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.physleta.2023.128957">10.1016/j.physleta.2023.128957 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Dynamical properties of quasiparticles in a tunable Kekul茅 graphene superlattice </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xiong%2C+X">Xiao-Yu Xiong</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+X">Xi-Dan Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qizhong Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Z">Zhi 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="2304.08227v1-abstract-short" style="display: inline;"> We investigate the dynamical properties of quasiparticles in graphene superlattices with three typical Kekul茅 distortions (i.e., Kekul茅-O, Kekul茅-Y and Kekul茅-M). On the one hand, we numerically show the visualized evolution process of Kekul茅 quasiparticles; while on the other hand, we analytically obtain the centroid trajectory of the quasiparticles, and both of them agree well with each other. T… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.08227v1-abstract-full').style.display = 'inline'; document.getElementById('2304.08227v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.08227v1-abstract-full" style="display: none;"> We investigate the dynamical properties of quasiparticles in graphene superlattices with three typical Kekul茅 distortions (i.e., Kekul茅-O, Kekul茅-Y and Kekul茅-M). On the one hand, we numerically show the visualized evolution process of Kekul茅 quasiparticles; while on the other hand, we analytically obtain the centroid trajectory of the quasiparticles, and both of them agree well with each other. The results reveal that the relativistic Zitterbewegung (ZB) phenomenon occurs in the Kekul茅 systems. Furthermore, through analyzing the frequency of ZB, we unveil the one-to-one relationship between ZB and Kekul茅 textures, i.e., the ZB frequenies of Kekul茅-O, Kekul茅-Y and Kekul茅-M quasiparticles feature single, double and six frequencies, respectively. Finally, we propose a scheme to distinguish among different Kekul茅 textures from the dynamical perspective. The predictions in this paper are expected to be experimentally verified in the near future, so as to facilitate further research of Kekul茅 structures in solid materials or artificial systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.08227v1-abstract-full').style.display = 'none'; document.getElementById('2304.08227v1-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.06706">arXiv:2301.06706</a> <span> [<a href="https://arxiv.org/pdf/2301.06706">pdf</a>, <a href="https://arxiv.org/ps/2301.06706">ps</a>, <a href="https://arxiv.org/format/2301.06706">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"> Feasibility Analysis of Grover-meets-Simon Algorithm </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qianru Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+H">Huiqin Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Xia%2C+Q">Qiqing Xia</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+L">Li Yang</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="2301.06706v1-abstract-short" style="display: inline;"> Quantum algorithm is a key tool for cryptanalysis. At present, people are committed to building powerful quantum algorithms and tapping the potential of quantum algorithms, so as to further analyze the security of cryptographic algorithms under quantum computing. Recombining classical quantum algorithms is one of the current ideas to construct quantum algorithms. However, they cannot be easily com… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.06706v1-abstract-full').style.display = 'inline'; document.getElementById('2301.06706v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.06706v1-abstract-full" style="display: none;"> Quantum algorithm is a key tool for cryptanalysis. At present, people are committed to building powerful quantum algorithms and tapping the potential of quantum algorithms, so as to further analyze the security of cryptographic algorithms under quantum computing. Recombining classical quantum algorithms is one of the current ideas to construct quantum algorithms. However, they cannot be easily combined, the feasibility of quantum algorithms needs further analysis in quantum environment. This paper reanalyzes the existing combined algorithm Grover-meets-Simon algorithm in terms of the principle of deferred measurement. First of all, due to the collapse problem caused by the measurement, we negate the measurement process of Simon's algorithm during the process of the Grover-meets-Simon algorithm. Second, since the output of the unmeasured Simon algorithm is quantum linear systems of equations, we discuss the solution of quantum linear systems of equations and find it feasible to consider the deferred measurement of the parallel Simon algorithm alone. Finally, since the Grover-meets-Simon algorithm involves an iterative problem, we reconsider the feasibility of the algorithm when placing multiple measurements at the end. According to the maximum probability of success and query times, we get that the Grover-meets-Simon algorithm is not an effective attack algorithm when putting the measurement process of the Simon algorithm in the iterative process at the end of Grover-meets-Simon algorithm. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.06706v1-abstract-full').style.display = 'none'; document.getElementById('2301.06706v1-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 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 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/2301.06094">arXiv:2301.06094</a> <span> [<a href="https://arxiv.org/pdf/2301.06094">pdf</a>, <a href="https://arxiv.org/format/2301.06094">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/PhysRevA.107.053302">10.1103/PhysRevA.107.053302 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Metastable supersolid in spin-orbit coupled Bose-Einstein condensates </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xia%2C+W">Wei-Lei Xia</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+L">Lei Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tian-Tian Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yongping Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qizhong Zhu</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="2301.06094v1-abstract-short" style="display: inline;"> Supersolid is a special state of matter with both superfluid properties and spontaneous modulation of particle density. In this paper, we focus on the supersolid stripe phase realized in a spin-orbit coupled Bose-Einstein condensate and explore the properties of a class of metastable supersolids. In particular, we study a one-dimensional supersolid whose characteristic wave number $k$ (magnitude o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.06094v1-abstract-full').style.display = 'inline'; document.getElementById('2301.06094v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.06094v1-abstract-full" style="display: none;"> Supersolid is a special state of matter with both superfluid properties and spontaneous modulation of particle density. In this paper, we focus on the supersolid stripe phase realized in a spin-orbit coupled Bose-Einstein condensate and explore the properties of a class of metastable supersolids. In particular, we study a one-dimensional supersolid whose characteristic wave number $k$ (magnitude of wave vector) deviates from $k_{m}$, i.e., the one at ground state. In other words, the period of density modulation is shorter or longer than the one at ground state. We find that this class of supersolids can still be stable if their wave numbers fall in the range $k_{c1}<k<k_{c2}$, with two thresholds $k_{c1}$ and $k_{c2}$. Stripes with $k$ outside this range suffer from dynamical instability with complex Bogoliubov excitation spectrum at long wavelength. Experimentally, these stripes with $k$ away from $k_m$ are accessible by exciting the longitudinal spin dipole mode, resulting in temporal oscillation of stripe period as well as $k$. Within the mean-field Gross-Pitaevskii theory, we numerically confirm that for a large enough amplitude of spin dipole oscillation, the stripe states become unstable through breaking periodicity, in qualitative agreement with the existence of thresholds of $k$ for stable stripes. Our work extends the concept of supersolid and uncovers a new class of metastable supersolids to explore. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.06094v1-abstract-full').style.display = 'none'; document.getElementById('2301.06094v1-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 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A 107, 053302 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.08006">arXiv:2212.08006</a> <span> [<a href="https://arxiv.org/pdf/2212.08006">pdf</a>, <a href="https://arxiv.org/format/2212.08006">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/s41567-024-02530-z">10.1038/s41567-024-02530-z <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental quantum computational chemistry with optimised unitary coupled cluster ansatz </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+J">Jinzhao Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yukun Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+K">Kun Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Ying%2C+C">Chong Ying</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shiyu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+J">Jiale Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+D">Daojin Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+D">Dachao Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Su%2C+H">Hong Su</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yuan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+K">Kaili Zhang</a> , et al. (13 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="2212.08006v3-abstract-short" style="display: inline;"> Quantum computational chemistry has emerged as an important application of quantum computing. Hybrid quantum-classical computing methods, such as variational quantum eigensolvers (VQE), have been designed as promising solutions to quantum chemistry problems, yet challenges due to theoretical complexity and experimental imperfections hinder progress in achieving reliable and accurate results. Exper… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.08006v3-abstract-full').style.display = 'inline'; document.getElementById('2212.08006v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.08006v3-abstract-full" style="display: none;"> Quantum computational chemistry has emerged as an important application of quantum computing. Hybrid quantum-classical computing methods, such as variational quantum eigensolvers (VQE), have been designed as promising solutions to quantum chemistry problems, yet challenges due to theoretical complexity and experimental imperfections hinder progress in achieving reliable and accurate results. Experimental works for solving electronic structures are consequently still restricted to nonscalable (hardware efficient) or classically simulable (Hartree-Fock) ansatz, or limited to a few qubits with large errors. The experimental realisation of scalable and high-precision quantum chemistry simulation remains elusive. Here, we address the critical challenges {associated with} solving molecular electronic structures using noisy quantum processors. Our protocol presents significant improvements in the circuit depth and running time, key metrics for chemistry simulation. Through systematic hardware enhancements and the integration of error mitigation techniques, we push forward the limit of experimental quantum computational chemistry and successfully scale up the implementation of VQE with an optimised unitary coupled-cluster ansatz to 12 qubits. We produce high-precision results of the ground-state energy for molecules with error suppression by around two orders of magnitude. We achieve chemical accuracy for H$_2$ at all bond distances and LiH at small bond distances in the experiment, even beyond the two recent concurrent works. Our work demonstrates a feasible path towards a scalable solution to electronic structure calculation, validating the key technological features and identifying future challenges for this goal. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.08006v3-abstract-full').style.display = 'none'; document.getElementById('2212.08006v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 4 figures in the main text, and 29 pages supplementary materials with 17 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/2212.02314">arXiv:2212.02314</a> <span> [<a href="https://arxiv.org/pdf/2212.02314">pdf</a>, <a href="https://arxiv.org/format/2212.02314">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="Statistics Theory">math.ST</span> </div> </div> <p class="title is-5 mathjax"> Finitely Repeated Adversarial Quantum Hypothesis Testing </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hu%2C+Y">Yinan Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Quanyan Zhu</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="2212.02314v1-abstract-short" style="display: inline;"> We formulate a passive quantum detector based on a quantum hypothesis testing framework under the setting of finite sample size. In particular, we exploit the fundamental limits of performance of the passive quantum detector asymptotically. Under the assumption that the attacker adopts separable optimal strategies, we derive that the worst-case average error bound converges to zero exponentially i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.02314v1-abstract-full').style.display = 'inline'; document.getElementById('2212.02314v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.02314v1-abstract-full" style="display: none;"> We formulate a passive quantum detector based on a quantum hypothesis testing framework under the setting of finite sample size. In particular, we exploit the fundamental limits of performance of the passive quantum detector asymptotically. Under the assumption that the attacker adopts separable optimal strategies, we derive that the worst-case average error bound converges to zero exponentially in terms of the number of repeated observations, which serves as a variation of quantum Sanov's theorem. We illustrate the general decaying results of miss rate numerically, depicting that the `naive' detector manages to achieve a miss rate and a false alarm rate both exponentially decaying to zero given infinitely many quantum states, although the miss rate decays to zero at a much slower rate than a quantum non-adversarial counterpart. Finally we adopt our formulations upon a case study of detection with quantum radars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.02314v1-abstract-full').style.display = 'none'; document.getElementById('2212.02314v1-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 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.11481">arXiv:2211.11481</a> <span> [<a href="https://arxiv.org/pdf/2211.11481">pdf</a>, <a href="https://arxiv.org/ps/2211.11481">ps</a>, <a href="https://arxiv.org/format/2211.11481">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> </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.107.013312">10.1103/PhysRevA.107.013312 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Magnetic monopole induced polarons in atomic superlattices </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Gao%2C+X">Xiang Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Cai%2C+Y">Ya-Fen Cai</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shao-Jun Li</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+S">Shou-Long Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Fang%2C+X">Xue-Ting Fang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qian-Ru Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+L">Lushuai Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Schmelcher%2C+P">Peter Schmelcher</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+Z">Zhong-Kun 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="2211.11481v1-abstract-short" style="display: inline;"> Magnetic monopoles have been realized as emergent quasiparticles in both condensed matter and ultracold atomic platforms, with growing interests in the coupling effects between the monopole and different magnetic quasiparticles. In this work, interaction effects between monopoles and magnons are investigated for an atomic pseudospin chain. We reveal that the monopole can excite a virtual magnon cl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.11481v1-abstract-full').style.display = 'inline'; document.getElementById('2211.11481v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.11481v1-abstract-full" style="display: none;"> Magnetic monopoles have been realized as emergent quasiparticles in both condensed matter and ultracold atomic platforms, with growing interests in the coupling effects between the monopole and different magnetic quasiparticles. In this work, interaction effects between monopoles and magnons are investigated for an atomic pseudospin chain. We reveal that the monopole can excite a virtual magnon cloud in the paramagnetic chain, thereby giving rise to a new type of polaron, the monopole-cored polaron (McP). The McP is composed of the monopole as the impurity core and the virtual magnon excitation as the dressing cloud. The magnon dressing facilitates the Dirac string excitation and impacts the monopole hopping. This induces an anti-trapping effect of the McP, which refers to the fact that the dressing enhances the mobility of the McP, in contrast to the self-trapping of the common polarons. Moreover, heterogeneous bipolarons are shown to exist under the simultaneous doping of a north and a south monopole. The heterogeneous bipolaron possesses an inner degree of freedom composed of two identical impurities. Our investigation sheds light on the understanding of how the coupling between the impurity core and the dressing cloud can engineer the property of the polaron <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.11481v1-abstract-full').style.display = 'none'; document.getElementById('2211.11481v1-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 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.09297">arXiv:2209.09297</a> <span> [<a href="https://arxiv.org/pdf/2209.09297">pdf</a>, <a href="https://arxiv.org/format/2209.09297">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> </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.130.210403">10.1103/PhysRevLett.130.210403 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Controlling local thermalization dynamics in a Floquet-engineered dipolar ensemble </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Martin%2C+L+S">Leigh S. Martin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+H">Hengyun Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Leitao%2C+N+T">Nathaniel T. Leitao</a>, <a href="/search/quant-ph?searchtype=author&query=Maskara%2C+N">Nishad Maskara</a>, <a href="/search/quant-ph?searchtype=author&query=Makarova%2C+O">Oksana Makarova</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+H">Haoyang Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qian-Ze Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Park%2C+M">Mincheol Park</a>, <a href="/search/quant-ph?searchtype=author&query=Tyler%2C+M">Matthew Tyler</a>, <a href="/search/quant-ph?searchtype=author&query=Park%2C+H">Hongkun Park</a>, <a href="/search/quant-ph?searchtype=author&query=Choi%2C+S">Soonwon Choi</a>, <a href="/search/quant-ph?searchtype=author&query=Lukin%2C+M+D">Mikhail D. Lukin</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2209.09297v2-abstract-short" style="display: inline;"> Understanding the microscopic mechanisms of thermalization in closed quantum systems is among the key challenges in modern quantum many-body physics. We demonstrate a method to probe local thermalization in a large-scale many-body system by exploiting its inherent disorder, and use this to uncover the thermalization mechanisms in a three-dimensional, dipolar-interacting spin system with tunable in… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.09297v2-abstract-full').style.display = 'inline'; document.getElementById('2209.09297v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.09297v2-abstract-full" style="display: none;"> Understanding the microscopic mechanisms of thermalization in closed quantum systems is among the key challenges in modern quantum many-body physics. We demonstrate a method to probe local thermalization in a large-scale many-body system by exploiting its inherent disorder, and use this to uncover the thermalization mechanisms in a three-dimensional, dipolar-interacting spin system with tunable interactions. Utilizing advanced Hamiltonian engineering techniques to explore a range of spin Hamiltonians, we observe a striking change in the characteristic shape and timescale of local correlation decay as we vary the engineered exchange anisotropy. We show that these observations originate from the system's intrinsic many-body dynamics and reveal the signatures of conservation laws within localized clusters of spins, which do not readily manifest using global probes. Our method provides an exquisite lens into the tunable nature of local thermalization dynamics, and enables detailed studies of scrambling, thermalization and hydrodynamics in strongly-interacting quantum systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.09297v2-abstract-full').style.display = 'none'; document.getElementById('2209.09297v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 4 figures main text</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 130, 210403 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.00459">arXiv:2206.00459</a> <span> [<a href="https://arxiv.org/pdf/2206.00459">pdf</a>, <a href="https://arxiv.org/ps/2206.00459">ps</a>, <a href="https://arxiv.org/format/2206.00459">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/PhysRevA.106.033315">10.1103/PhysRevA.106.033315 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Manifold formation and crossings of ultracold lattice spinor atoms in the intermediate interaction regime </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fang%2C+X">Xue-Ting Fang</a>, <a href="/search/quant-ph?searchtype=author&query=Dai%2C+Z">Zheng-Qi Dai</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+D">Di Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+S">Shou-Long Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shao-Jun Li</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+X">Xiang Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qian-Ru Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+X">Xing Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+L">Lushuai Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+Z">Zhong-Kun 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="2206.00459v1-abstract-short" style="display: inline;"> Ultracold spinor atoms in the weak and strong interaction regime have received extensive investigations, while the behavior in the intermediate regime is less understood. We numerically investigate ultracold spinor atomic ensembles of finite size in the intermediate interaction regime, and reveal the evolution of the eigenstates from the strong to the intermediate regime. In the strong interaction… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.00459v1-abstract-full').style.display = 'inline'; document.getElementById('2206.00459v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.00459v1-abstract-full" style="display: none;"> Ultracold spinor atoms in the weak and strong interaction regime have received extensive investigations, while the behavior in the intermediate regime is less understood. We numerically investigate ultracold spinor atomic ensembles of finite size in the intermediate interaction regime, and reveal the evolution of the eigenstates from the strong to the intermediate regime. In the strong interaction regime, it has been well known that the low-lying eigenenergy spectrum presents the well-gaped multi-manifold structure, and the energy gaps protect the categorization of the eigenstates. In the intermediate interaction regime, it is found that the categorization of the eigenstates is preserved, and the eigenenergy spectrum become quasi-continuum, with different manifolds becoming overlapped. The overlapping induces both direct and avoided crossings between close-lying manifolds, which is determined by the combined symmetries of the eigenstates involved in the crossing. A modified t-J model is derived to describe the low-lying eigenstates in the intermediate regime, which can capture the formation and crossings of the manifolds. State preparation through the avoided crossings is also investigated. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.00459v1-abstract-full').style.display = 'none'; document.getElementById('2206.00459v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages,6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> 106, 033315(2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.04598">arXiv:2203.04598</a> <span> [<a href="https://arxiv.org/pdf/2203.04598">pdf</a>, <a href="https://arxiv.org/format/2203.04598">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/AO.457662">10.1364/AO.457662 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Practical underwater quantum key distribution based on decoy-state BB84 protocol </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Dong%2C+S">Shanchuan Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+Y">Yonghe Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+S">Shangshuai Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qiming Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Gai%2C+L">Lei Gai</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+W">Wendong Li</a>, <a href="/search/quant-ph?searchtype=author&query=Gu%2C+Y">Yongjian Gu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.04598v1-abstract-short" style="display: inline;"> Polarization encoding quantum key distribution has been proven to be a reliable method to build a secure communication system. It has already been used in inter-city fiber channel and near-earth atmosphere channel, leaving underwater channel the last barrier to conquer. Here we demonstrate a decoy-state BB84 quantum key distribution system over a water channel with a compact system design for futu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.04598v1-abstract-full').style.display = 'inline'; document.getElementById('2203.04598v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.04598v1-abstract-full" style="display: none;"> Polarization encoding quantum key distribution has been proven to be a reliable method to build a secure communication system. It has already been used in inter-city fiber channel and near-earth atmosphere channel, leaving underwater channel the last barrier to conquer. Here we demonstrate a decoy-state BB84 quantum key distribution system over a water channel with a compact system design for future experiments in the ocean. In the system, a multiple-intensity modulated laser module is designed to produce the light pulses of quantum states, including signal state, decoy state and vacuum state. The classical communication and synchronization are realized by wireless optical transmission. Multiple filtering techniques and wavelength division multiplexing are further used to avoid crosstalk of different light. We test the performance of the system and obtain a final key rate of 245.6 bps with an average QBER of 1.91% over a 2.4m water channel, in which the channel attenuation is 16.35dB. Numerical simulation shows that the system can tolerate up to 21.7dB total channel loss and can still generate secure keys in 277.9m Jelov type 1 ocean channel. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.04598v1-abstract-full').style.display = 'none'; document.getElementById('2203.04598v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2202.06616">arXiv:2202.06616</a> <span> [<a href="https://arxiv.org/pdf/2202.06616">pdf</a>, <a href="https://arxiv.org/format/2202.06616">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/10.1088/0256-307X/39/3/030302">10.1088/0256-307X/39/3/030302 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Realization of fast all-microwave CZ gates with a tunable coupler </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+D">Daojin Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+X">Xiawei Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Guan%2C+H">Huijie Guan</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Yan%2C+K">Kai Yan</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+H">Haibin Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shiyu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Ying%2C+C">Chong Ying</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+J">Jiale Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</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="2202.06616v1-abstract-short" style="display: inline;"> The development of high-fidelity two-qubit quantum gates is essential for digital quantum computing. Here, we propose and realize an all-microwave parametric Controlled-Z (CZ) gates by coupling strength modulation in a superconducting Transmon qubit system with tunable couplers. After optimizing the design of the tunable coupler together with the control pulse numerically, we experimentally realiz… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.06616v1-abstract-full').style.display = 'inline'; document.getElementById('2202.06616v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2202.06616v1-abstract-full" style="display: none;"> The development of high-fidelity two-qubit quantum gates is essential for digital quantum computing. Here, we propose and realize an all-microwave parametric Controlled-Z (CZ) gates by coupling strength modulation in a superconducting Transmon qubit system with tunable couplers. After optimizing the design of the tunable coupler together with the control pulse numerically, we experimentally realized a 100 ns CZ gate with high fidelity of 99.38%$ \pm$0.34% and the control error being 0.1%. We note that our CZ gates are not affected by pulse distortion and do not need pulse correction, {providing a solution for the real-time pulse generation in a dynamic quantum feedback circuit}. With the expectation of utilizing our all-microwave control scheme to reduce the number of control lines through frequency multiplexing in the future, our scheme draws a blueprint for the high-integrable quantum hardware design. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2202.06616v1-abstract-full').style.display = 'none'; document.getElementById('2202.06616v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 February, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Chin. Phys. Lett.,39 (3): 030302 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.05957">arXiv:2201.05957</a> <span> [<a href="https://arxiv.org/pdf/2201.05957">pdf</a>, <a href="https://arxiv.org/format/2201.05957">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/10.1016/j.scib.2023.04.003">10.1016/j.scib.2023.04.003 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Quantum Neuronal Sensing of Quantum Many-Body States on a 61-Qubit Programmable Superconducting Processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shiyu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Chu Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Ying%2C+C">Chong Ying</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+J">Jiale Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+D">Daojin Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+D">Dachao Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Su%2C+H">Hong Su</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+K">Kaili Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+L">Lihua Sun</a> , et al. (11 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="2201.05957v2-abstract-short" style="display: inline;"> Classifying many-body quantum states with distinct properties and phases of matter is one of the most fundamental tasks in quantum many-body physics. However, due to the exponential complexity that emerges from the enormous numbers of interacting particles, classifying large-scale quantum states has been extremely challenging for classical approaches. Here, we propose a new approach called quantum… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.05957v2-abstract-full').style.display = 'inline'; document.getElementById('2201.05957v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.05957v2-abstract-full" style="display: none;"> Classifying many-body quantum states with distinct properties and phases of matter is one of the most fundamental tasks in quantum many-body physics. However, due to the exponential complexity that emerges from the enormous numbers of interacting particles, classifying large-scale quantum states has been extremely challenging for classical approaches. Here, we propose a new approach called quantum neuronal sensing. Utilizing a 61 qubit superconducting quantum processor, we show that our scheme can efficiently classify two different types of many-body phenomena: namely the ergodic and localized phases of matter. Our quantum neuronal sensing process allows us to extract the necessary information coming from the statistical characteristics of the eigenspectrum to distinguish these phases of matter by measuring only one qubit. Our work demonstrates the feasibility and scalability of quantum neuronal sensing for near-term quantum processors and opens new avenues for exploring quantum many-body phenomena in larger-scale systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.05957v2-abstract-full').style.display = 'none'; document.getElementById('2201.05957v2-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 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 3 figures in the main text, and 13 pages, 13 figures, and 1 table in supplementary materials</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science Bulletin, 68(9):906-912 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.13505">arXiv:2112.13505</a> <span> [<a href="https://arxiv.org/pdf/2112.13505">pdf</a>, <a href="https://arxiv.org/format/2112.13505">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.129.030501">10.1103/PhysRevLett.129.030501 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Realization of an Error-Correcting Surface Code with Superconducting Qubits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yiming Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+D">Dachao Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Guan%2C+H">Huijie Guan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Wei%2C+Z">Zuolin Wei</a>, <a href="/search/quant-ph?searchtype=author&query=He%2C+T">Tan He</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chung%2C+T">Tung-Hsun Chung</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+D">Daojin Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Cheng Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Han%2C+L">Lianchen Han</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+N">Na Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yuan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a> , et al. (14 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="2112.13505v2-abstract-short" style="display: inline;"> Quantum error correction is a critical technique for transitioning from noisy intermediate-scale quantum (NISQ) devices to fully fledged quantum computers. The surface code, which has a high threshold error rate, is the leading quantum error correction code for two-dimensional grid architecture. So far, the repeated error correction capability of the surface code has not been realized experimental… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.13505v2-abstract-full').style.display = 'inline'; document.getElementById('2112.13505v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.13505v2-abstract-full" style="display: none;"> Quantum error correction is a critical technique for transitioning from noisy intermediate-scale quantum (NISQ) devices to fully fledged quantum computers. The surface code, which has a high threshold error rate, is the leading quantum error correction code for two-dimensional grid architecture. So far, the repeated error correction capability of the surface code has not been realized experimentally. Here, we experimentally implement an error-correcting surface code, the distance-3 surface code which consists of 17 qubits, on the \textit{Zuchongzhi} 2.1 superconducting quantum processor. By executing several consecutive error correction cycles, the logical error can be significantly reduced after applying corrections, achieving the repeated error correction of surface code for the first time. This experiment represents a fully functional instance of an error-correcting surface code, providing a key step on the path towards scalable fault-tolerant quantum computing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.13505v2-abstract-full').style.display = 'none'; document.getElementById('2112.13505v2-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 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 129, 030501 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.03496">arXiv:2112.03496</a> <span> [<a href="https://arxiv.org/pdf/2112.03496">pdf</a>, <a href="https://arxiv.org/ps/2112.03496">ps</a>, <a href="https://arxiv.org/format/2112.03496">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/PhysRevA.105.053308">10.1103/PhysRevA.105.053308 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Interaction effects of pseudospin-based magnetic monopoles and kinks in a doped dipolar superlattice gas </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Gao%2C+X">Xiang Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shao-Jun Li</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+S">Shou-Long Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Fang%2C+X">Xue-Ting Fang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qian-Ru Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+X">Xing Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+L">Lushuai Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Schmelcher%2C+P">Peter Schmelcher</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+Z">Zhong-Kun 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="2112.03496v2-abstract-short" style="display: inline;"> Magnetic monopoles and kinks are topological excitations extensively investigated in quantum spin systems, but usually they are studied in different setups. We explore the conditions for the coexistence and the interaction effects of these quasiparticles in the pseudospin chain of the atomic dipolar superlattice gas. In this chain, the magnetic kink is the intrinsic quasiparticle, and the particle… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.03496v2-abstract-full').style.display = 'inline'; document.getElementById('2112.03496v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.03496v2-abstract-full" style="display: none;"> Magnetic monopoles and kinks are topological excitations extensively investigated in quantum spin systems, but usually they are studied in different setups. We explore the conditions for the coexistence and the interaction effects of these quasiparticles in the pseudospin chain of the atomic dipolar superlattice gas. In this chain, the magnetic kink is the intrinsic quasiparticle, and the particle/hole defect takes over the role of the north/south magnetic monopole, exerting monopolar magnetic fields to neighboring spins. A confinement effect between the monopole and kink is revealed, which renormalizes the dispersion of the kink. The corresponding dynamical deconfinement process is observed and arises due to the kink-antikink annihilation. The rich interaction effects of the two quasiparticles could stimulate corresponding investigations in bulk spin systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.03496v2-abstract-full').style.display = 'none'; document.getElementById('2112.03496v2-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.05680">arXiv:2109.05680</a> <span> [<a href="https://arxiv.org/pdf/2109.05680">pdf</a>, <a href="https://arxiv.org/format/2109.05680">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/10.1088/0256-307X/38/10/100301">10.1088/0256-307X/38/10/100301 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Realization of high-fidelity CZ gates in extensible superconducting qubits design with a tunable coupler </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+X">Xiawei Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shiyu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Cheng Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+L">Lihua Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+N">Na Li</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xiaobo Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Pan%2C+J">Jian-Wei Pan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.05680v1-abstract-short" style="display: inline;"> High-fidelity two-qubits gates are essential for the realization of large-scale quantum computation and simulation. Tunable coupler design is used to reduce the problem of parasitic coupling and frequency crowding in many-qubit systems and thus thought to be advantageous. Here we design a extensible 5-qubit system in which center transmon qubit can couple to every four near-neighbor qubit via a ca… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.05680v1-abstract-full').style.display = 'inline'; document.getElementById('2109.05680v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.05680v1-abstract-full" style="display: none;"> High-fidelity two-qubits gates are essential for the realization of large-scale quantum computation and simulation. Tunable coupler design is used to reduce the problem of parasitic coupling and frequency crowding in many-qubit systems and thus thought to be advantageous. Here we design a extensible 5-qubit system in which center transmon qubit can couple to every four near-neighbor qubit via a capacitive tunable coupler and experimentally demonstrate high-fidelity controlled-phase (CZ) gate by manipulating center qubit and one near-neighbor qubit. Speckle purity benchmarking (SPB) and cross entrophy benchmarking (XEB) are used to assess the purity fidelity and the fidelity of the CZ gate. The average purity fidelity of the CZ gate is 99.69$\pm$0.04\% and the average fidelity of the CZ gate is 99.65$\pm$0.04\% which means the control error is about 0.04\%. Our work will help resovle many chanllenges in the implementation of large scale quantum systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.05680v1-abstract-full').style.display = 'none'; document.getElementById('2109.05680v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 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/2109.03494">arXiv:2109.03494</a> <span> [<a href="https://arxiv.org/pdf/2109.03494">pdf</a>, <a href="https://arxiv.org/format/2109.03494">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 Computational Advantage via 60-Qubit 24-Cycle Random Circuit Sampling </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+M">Ming-Cheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+X">Xiawei Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chung%2C+T">Tung-Hsun Chung</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+Y">Yajie Du</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+D">Daojin Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Cheng Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Chu Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Han%2C+L">Lianchen Han</a>, <a href="/search/quant-ph?searchtype=author&query=Hong%2C+L">Linyin Hong</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Huo%2C+Y">Yong-Heng Huo</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+L">Liping Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+N">Na Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yuan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+C">Chun Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a> , et al. (28 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2109.03494v2-abstract-short" style="display: inline;"> To ensure a long-term quantum computational advantage, the quantum hardware should be upgraded to withstand the competition of continuously improved classical algorithms and hardwares. Here, we demonstrate a superconducting quantum computing systems \textit{Zuchongzhi} 2.1, which has 66 qubits in a two-dimensional array in a tunable coupler architecture. The readout fidelity of \textit{Zuchongzhi}… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.03494v2-abstract-full').style.display = 'inline'; document.getElementById('2109.03494v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.03494v2-abstract-full" style="display: none;"> To ensure a long-term quantum computational advantage, the quantum hardware should be upgraded to withstand the competition of continuously improved classical algorithms and hardwares. Here, we demonstrate a superconducting quantum computing systems \textit{Zuchongzhi} 2.1, which has 66 qubits in a two-dimensional array in a tunable coupler architecture. The readout fidelity of \textit{Zuchongzhi} 2.1 is considerably improved to an average of 97.74\%. The more powerful quantum processor enables us to achieve larger-scale random quantum circuit sampling, with a system scale of up to 60 qubits and 24 cycles. The achieved sampling task is about 6 orders of magnitude more difficult than that of Sycamore [Nature \textbf{574}, 505 (2019)] in the classic simulation, and 3 orders of magnitude more difficult than the sampling task on \textit{Zuchongzhi} 2.0 [arXiv:2106.14734 (2021)]. The time consumption of classically simulating random circuit sampling experiment using state-of-the-art classical algorithm and supercomputer is extended to tens of thousands of years (about $4.8\times 10^4$ years), while \textit{Zuchongzhi} 2.1 only takes about 4.2 hours, thereby significantly enhancing the quantum computational advantage. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.03494v2-abstract-full').style.display = 'none'; document.getElementById('2109.03494v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.07311">arXiv:2107.07311</a> <span> [<a href="https://arxiv.org/pdf/2107.07311">pdf</a>, <a href="https://arxiv.org/ps/2107.07311">ps</a>, <a href="https://arxiv.org/format/2107.07311">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.105.012418">10.1103/PhysRevA.105.012418 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Floquet Prethermal Phase Protected by U(1) Symmetry on a Superconducting Quantum Processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Ying%2C+C">Chong Ying</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+Q">Qihao Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+X">Xiu-Hao Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+C">Can Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shiyu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Peng%2C+C">Cheng-Zhi Peng</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+C">Chao-Yang Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+Z">Zhang-Qi Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xiaobo Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Pan%2C+J">Jian-Wei Pan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2107.07311v1-abstract-short" style="display: inline;"> Periodically driven systems, or Floquet systems, exhibit many novel dynamics and interesting out-of-equilibrium phases of matter. Those phases arising with the quantum systems' symmetries, such as global $U(1)$ symmetry, can even show dynamical stability with symmetry-protection. Here we experimentally demonstrate a $U(1)$ symmetry-protected prethermal phase, via performing a digital-analog quantu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.07311v1-abstract-full').style.display = 'inline'; document.getElementById('2107.07311v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.07311v1-abstract-full" style="display: none;"> Periodically driven systems, or Floquet systems, exhibit many novel dynamics and interesting out-of-equilibrium phases of matter. Those phases arising with the quantum systems' symmetries, such as global $U(1)$ symmetry, can even show dynamical stability with symmetry-protection. Here we experimentally demonstrate a $U(1)$ symmetry-protected prethermal phase, via performing a digital-analog quantum simulation on a superconducting quantum processor. The dynamical stability of this phase is revealed by its robustness against external perturbations. We also find that the spin glass order parameter in this phase is stabilized by the interaction between the spins. Our work reveals a promising prospect in discovering emergent quantum dynamical phases with digital-analog quantum simulators. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.07311v1-abstract-full').style.display = 'none'; document.getElementById('2107.07311v1-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 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 4 figures, and supplementary materials</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.14734">arXiv:2106.14734</a> <span> [<a href="https://arxiv.org/pdf/2106.14734">pdf</a>, <a href="https://arxiv.org/format/2106.14734">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.127.180501">10.1103/PhysRevLett.127.180501 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Strong quantum computational advantage using a superconducting quantum processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+W">Wan-Su Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+M">Ming-Cheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+X">Xiawei Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chung%2C+T">Tung-Hsun Chung</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+Y">Yajie Du</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+D">Daojin Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Cheng Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Chu Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Han%2C+L">Lianchen Han</a>, <a href="/search/quant-ph?searchtype=author&query=Hong%2C+L">Linyin Hong</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Huo%2C+Y">Yong-Heng Huo</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+L">Liping Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+N">Na Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yuan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+C">Chun Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a> , et al. (29 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="2106.14734v1-abstract-short" style="display: inline;"> Scaling up to a large number of qubits with high-precision control is essential in the demonstrations of quantum computational advantage to exponentially outpace the classical hardware and algorithmic improvements. Here, we develop a two-dimensional programmable superconducting quantum processor, \textit{Zuchongzhi}, which is composed of 66 functional qubits in a tunable coupling architecture. To… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.14734v1-abstract-full').style.display = 'inline'; document.getElementById('2106.14734v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.14734v1-abstract-full" style="display: none;"> Scaling up to a large number of qubits with high-precision control is essential in the demonstrations of quantum computational advantage to exponentially outpace the classical hardware and algorithmic improvements. Here, we develop a two-dimensional programmable superconducting quantum processor, \textit{Zuchongzhi}, which is composed of 66 functional qubits in a tunable coupling architecture. To characterize the performance of the whole system, we perform random quantum circuits sampling for benchmarking, up to a system size of 56 qubits and 20 cycles. The computational cost of the classical simulation of this task is estimated to be 2-3 orders of magnitude higher than the previous work on 53-qubit Sycamore processor [Nature \textbf{574}, 505 (2019)]. We estimate that the sampling task finished by \textit{Zuchongzhi} in about 1.2 hours will take the most powerful supercomputer at least 8 years. Our work establishes an unambiguous quantum computational advantage that is infeasible for classical computation in a reasonable amount of time. The high-precision and programmable quantum computing platform opens a new door to explore novel many-body phenomena and implement complex quantum algorithms. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.14734v1-abstract-full').style.display = 'none'; document.getElementById('2106.14734v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.13441">arXiv:2106.13441</a> <span> [<a href="https://arxiv.org/pdf/2106.13441">pdf</a>, <a href="https://arxiv.org/format/2106.13441">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.435079">10.1364/OE.435079 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental Demonstration of Underwater Decoy-state Quantum Key Distribution with All-optical Transmission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yu%2C+Y">Yonghe Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+W">Wendong Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wei%2C+Y">Yu Wei</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Y">Yang Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+S">Shanchuan Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+T">Tian Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shuo Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qiming Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+S">Shangshuai Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+X">Xinjian Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Gu%2C+Y">Yongjian Gu</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="2106.13441v1-abstract-short" style="display: inline;"> We demonstrate the underwater quantum key distribution (UWQKD) over a 10.4-meter Jerlov type III seawater channel by building a complete UWQKD system with all-optical transmission of quantum signals, synchronization signal and classical communication signal. The wavelength division multiplexing and the space-time-wavelength filtering technology are applied to ensure that the optical signals do not… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.13441v1-abstract-full').style.display = 'inline'; document.getElementById('2106.13441v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.13441v1-abstract-full" style="display: none;"> We demonstrate the underwater quantum key distribution (UWQKD) over a 10.4-meter Jerlov type III seawater channel by building a complete UWQKD system with all-optical transmission of quantum signals, synchronization signal and classical communication signal. The wavelength division multiplexing and the space-time-wavelength filtering technology are applied to ensure that the optical signals do not interfere with each other. The system is controlled by FPGA, and can be easily integrated into watertight cabins to perform field experiment. By using the decoy-state BB84 protocol with polarization encoding, we obtain a secure key rate of 1.82Kbps and an error rate of 1.55% at the attenuation of 13.26dB. We prove that the system can tolerate the channel loss up to 23.7dB, therefore may be used in the 300-meter-long Jerlov type I clean seawater channel. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.13441v1-abstract-full').style.display = 'none'; document.getElementById('2106.13441v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 7 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2102.08587">arXiv:2102.08587</a> <span> [<a href="https://arxiv.org/pdf/2102.08587">pdf</a>, <a href="https://arxiv.org/format/2102.08587">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.127.020602">10.1103/PhysRevLett.127.020602 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of strong and weak thermalization in a superconducting quantum processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+Z">Zheng-Hang Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yu-Ran Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+J">Jiale Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+L">Lihua Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Cheng Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+N">Na Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Peng%2C+C">Cheng-Zhi Peng</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+H">Heng Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xiaobo Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Pan%2C+J">Jian-Wei Pan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2102.08587v1-abstract-short" style="display: inline;"> We experimentally study the ergodic dynamics of a 1D array of 12 superconducting qubits with a transverse field, and identify the regimes of strong and weak thermalization with different initial states. We observe convergence of the local observable to its thermal expectation value in the strong-thermalizaion regime. For weak thermalization, the dynamics of local observable exhibits an oscillation… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.08587v1-abstract-full').style.display = 'inline'; document.getElementById('2102.08587v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2102.08587v1-abstract-full" style="display: none;"> We experimentally study the ergodic dynamics of a 1D array of 12 superconducting qubits with a transverse field, and identify the regimes of strong and weak thermalization with different initial states. We observe convergence of the local observable to its thermal expectation value in the strong-thermalizaion regime. For weak thermalization, the dynamics of local observable exhibits an oscillation around the thermal value, which can only be attained by the time average. We also demonstrate that the entanglement entropy and concurrence can characterize the regimes of strong and weak thermalization. Our work provides an essential step towards a generic understanding of thermalization in quantum systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.08587v1-abstract-full').style.display = 'none'; document.getElementById('2102.08587v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 February, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6+6 pages, 4+8 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 127, 020602 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2102.02573">arXiv:2102.02573</a> <span> [<a href="https://arxiv.org/pdf/2102.02573">pdf</a>, <a href="https://arxiv.org/format/2102.02573">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1126/science.abg7812">10.1126/science.abg7812 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Quantum walks on a programmable two-dimensional 62-qubit superconducting processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shiyu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+M">Ming-Cheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Ying%2C+C">Chong Ying</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+J">Jiale Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+D">Daojin Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+D">Dachao Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Su%2C+H">Hong Su</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+K">Kaili Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Sirui Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+L">Lihua Sun</a> , et al. (11 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="2102.02573v3-abstract-short" style="display: inline;"> Quantum walks are the quantum mechanical analogue of classical random walks and an extremely powerful tool in quantum simulations, quantum search algorithms, and even for universal quantum computing. In our work, we have designed and fabricated an 8x8 two-dimensional square superconducting qubit array composed of 62 functional qubits. We used this device to demonstrate high fidelity single and two… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.02573v3-abstract-full').style.display = 'inline'; document.getElementById('2102.02573v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2102.02573v3-abstract-full" style="display: none;"> Quantum walks are the quantum mechanical analogue of classical random walks and an extremely powerful tool in quantum simulations, quantum search algorithms, and even for universal quantum computing. In our work, we have designed and fabricated an 8x8 two-dimensional square superconducting qubit array composed of 62 functional qubits. We used this device to demonstrate high fidelity single and two particle quantum walks. Furthermore, with the high programmability of the quantum processor, we implemented a Mach-Zehnder interferometer where the quantum walker coherently traverses in two paths before interfering and exiting. By tuning the disorders on the evolution paths, we observed interference fringes with single and double walkers. Our work is an essential milestone in the field, brings future larger scale quantum applications closer to realization on these noisy intermediate-scale quantum processors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.02573v3-abstract-full').style.display = 'none'; document.getElementById('2102.02573v3-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 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 February, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 4 figures, and supplementary materials with 21 pages, 13 figures and 1 table</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science 372, 948-952 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.08031">arXiv:2101.08031</a> <span> [<a href="https://arxiv.org/pdf/2101.08031">pdf</a>, <a href="https://arxiv.org/format/2101.08031">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.128.160502">10.1103/PhysRevLett.128.160502 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of thermalization and information scrambling in a superconducting quantum processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+Z">Zheng-Hang Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+F">Fusheng Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yu-Ran Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+S">Shaojun Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Qian%2C+H">Haoran Qian</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+H">He-Liang Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+J">Jiale Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+L">Lihua Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Cheng Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+N">Na Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Peng%2C+C">Cheng-Zhi Peng</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+H">Heng Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xiaobo Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Pan%2C+J">Jian-Wei Pan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.08031v1-abstract-short" style="display: inline;"> Understanding various phenomena in non-equilibrium dynamics of closed quantum many-body systems, such as quantum thermalization, information scrambling, and nonergodic dynamics, is a crucial for modern physics. Using a ladder-type superconducting quantum processor, we perform analog quantum simulations of both the $XX$ ladder and one-dimensional (1D) $XX$ model. By measuring the dynamics of local… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.08031v1-abstract-full').style.display = 'inline'; document.getElementById('2101.08031v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.08031v1-abstract-full" style="display: none;"> Understanding various phenomena in non-equilibrium dynamics of closed quantum many-body systems, such as quantum thermalization, information scrambling, and nonergodic dynamics, is a crucial for modern physics. Using a ladder-type superconducting quantum processor, we perform analog quantum simulations of both the $XX$ ladder and one-dimensional (1D) $XX$ model. By measuring the dynamics of local observables, entanglement entropy and tripartite mutual information, we signal quantum thermalization and information scrambling in the $XX$ ladder. In contrast, we show that the $XX$ chain, as free fermions on a 1D lattice, fails to thermalize, and local information does not scramble in the integrable channel. Our experiments reveal ergodicity and scrambling in the controllable qubit ladder, and opens the door to further investigations on the thermodynamics and chaos in quantum many-body systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.08031v1-abstract-full').style.display = 'none'; document.getElementById('2101.08031v1-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 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 4 figures, and supplementary materials with 10 pages, 3 tables and 14 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 128, 160502 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.11521">arXiv:2012.11521</a> <span> [<a href="https://arxiv.org/pdf/2012.11521">pdf</a>, <a href="https://arxiv.org/format/2012.11521">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div 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/PhysRevResearch.3.033043">10.1103/PhysRevResearch.3.033043 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental characterization of quantum many-body localization transition </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Neto%2C+G+D+d+M">Gentil D. de Moraes Neto</a>, <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shiyu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Peng%2C+C">Cheng-Zhi Peng</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Bayat%2C+A">Abolfazl Bayat</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xiaobo Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Pan%2C+J">Jian-Wei Pan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2012.11521v1-abstract-short" style="display: inline;"> As strength of disorder enhances beyond a threshold value in many-body systems, a fundamental transformation happens through which the entire spectrum localizes, a phenomenon known as many-body localization. This has profound implications as it breaks down fundamental principles of statistical mechanics, such as thermalization and ergodicity. Due to the complexity of the problem, the investigation… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.11521v1-abstract-full').style.display = 'inline'; document.getElementById('2012.11521v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.11521v1-abstract-full" style="display: none;"> As strength of disorder enhances beyond a threshold value in many-body systems, a fundamental transformation happens through which the entire spectrum localizes, a phenomenon known as many-body localization. This has profound implications as it breaks down fundamental principles of statistical mechanics, such as thermalization and ergodicity. Due to the complexity of the problem, the investigation of the many-body localization transition has remained a big challenge. The experimental exploration of the transition point is even more challenging as most of the proposed quantities for studying such effect are practically infeasible. Here, we experimentally implement a scalable protocol for detecting the many-body localization transition point, using the dynamics of a $N=12$ superconducting qubit array. We show that the sensitivity of the dynamics to random samples becomes maximum at the transition point which leaves its fingerprints in all spatial scales. By exploiting three quantities, each with different spatial resolution, we identify the transition point with excellent match between simulation and experiment. In addition, one can detect the evidence of mobility edge through slight variation of the transition point as the initial state varies. The protocol is easily scalable and can be performed across various physical platforms. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.11521v1-abstract-full').style.display = 'none'; document.getElementById('2012.11521v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages and 4 figures together with supplementary materials</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Research 3, 033043 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2002.10877">arXiv:2002.10877</a> <span>  </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"> Generating lightwave-photon-and-magnon entanglement with a mechanical oscillator as a "cold reservoir" </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Z">Zhi-Bo Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+J">Jin-Song Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+H">Hua Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qing-Hao Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+H">Hong-Yu Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+A">Ai-Dong Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+R">Rong-Can Yang</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="2002.10877v2-abstract-short" style="display: inline;"> We present a scheme to implement a steady lightwave-photon-and-magnon entanglement in a hybrid photon-magnon system by adiabatically eliminating the auxiliary microwave cavity and effectively laser cooling a delocalized Bogoliubov mode. The system consists of magnons, lightwave and microwave photons, and phonons. The magnons are embodied by a collective motion of a large number of spins in a macro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.10877v2-abstract-full').style.display = 'inline'; document.getElementById('2002.10877v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.10877v2-abstract-full" style="display: none;"> We present a scheme to implement a steady lightwave-photon-and-magnon entanglement in a hybrid photon-magnon system by adiabatically eliminating the auxiliary microwave cavity and effectively laser cooling a delocalized Bogoliubov mode. The system consists of magnons, lightwave and microwave photons, and phonons. The magnons are embodied by a collective motion of a large number of spins in a macroscopic ferrimagnet. To achieve an entangling interaction between magnons and lightwave photons, we drive optical cavity and magnon at the red and blue sideband associated with the mechanical resonator. In particular, optimizing the relative ratio of effect couplings, rather than simply increasing their magnitudes, is essential for achieving strong entanglement. Unlike typical dissipative entanglement schemes, our results cannot be described by treating the effects of the entangling reservoir via a Linblad master equation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.10877v2-abstract-full').style.display = 'none'; document.getElementById('2002.10877v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">There are some great mistakes and problems on the contents, languages and references</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.09169">arXiv:2001.09169</a> <span> [<a href="https://arxiv.org/pdf/2001.09169">pdf</a>, <a href="https://arxiv.org/format/2001.09169">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Disordered Systems and Neural Networks">cond-mat.dis-nn</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.125.170503">10.1103/PhysRevLett.125.170503 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ergodic-localized junctions in a periodically-driven spin chain </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zha%2C+C">Chen Zha</a>, <a href="/search/quant-ph?searchtype=author&query=Bastidas%2C+V+M">V. M. Bastidas</a>, <a href="/search/quant-ph?searchtype=author&query=Gong%2C+M">Ming Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yulin Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+H">Hao Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+R">Rui Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+Y">Yangsen Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaowei Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qingling Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shiyu Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Youwei Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+F">Futian Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+J">Jin Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Peng%2C+C">Cheng-Zhi Peng</a>, <a href="/search/quant-ph?searchtype=author&query=Schmiedmayer%2C+J">Jorg Schmiedmayer</a>, <a href="/search/quant-ph?searchtype=author&query=Nemoto%2C+K">Kae Nemoto</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+H">Hui Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Munro%2C+W+J">W. J. Munro</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+X">Xiaobo Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Pan%2C+J">Jian-Wei Pan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2001.09169v3-abstract-short" style="display: inline;"> We report the analogue simulation of an ergodiclocalized junction by using an array of 12 coupled superconducting qubits. To perform the simulation, we fabricated a superconducting quantum processor that is divided into two domains: a driven domain representing an ergodic system, while the second is localized under the effect of disorder. Due to the overlap between localized and delocalized states… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.09169v3-abstract-full').style.display = 'inline'; document.getElementById('2001.09169v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.09169v3-abstract-full" style="display: none;"> We report the analogue simulation of an ergodiclocalized junction by using an array of 12 coupled superconducting qubits. To perform the simulation, we fabricated a superconducting quantum processor that is divided into two domains: a driven domain representing an ergodic system, while the second is localized under the effect of disorder. Due to the overlap between localized and delocalized states, for small disorder there is a proximity effect and localization is destroyed. To experimentally investigate this, we prepare a microwave excitation in the driven domain and explore how deep it can penetrate the disordered region by probing its dynamics. Furthermore, we performed an ensemble average over 50 realizations of disorder, which clearly shows the proximity effect. Our work opens a new avenue to build quantum simulators of driven-disordered systems with applications in condensed matter physics and material science <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.09169v3-abstract-full').style.display = 'none'; document.getElementById('2001.09169v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 125, 170503 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1909.00028">arXiv:1909.00028</a> <span> [<a href="https://arxiv.org/pdf/1909.00028">pdf</a>, <a href="https://arxiv.org/format/1909.00028">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="Chemical Physics">physics.chem-ph</span> </div> </div> <p class="title is-5 mathjax"> Discontinuous Galerkin discretization for quantum simulation of chemistry </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=McClean%2C+J+R">Jarrod R. McClean</a>, <a href="/search/quant-ph?searchtype=author&query=Faulstich%2C+F+M">Fabian M. Faulstich</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qinyi Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=O%27Gorman%2C+B">Bryan O'Gorman</a>, <a href="/search/quant-ph?searchtype=author&query=Qiu%2C+Y">Yiheng Qiu</a>, <a href="/search/quant-ph?searchtype=author&query=White%2C+S+R">Steven R. White</a>, <a href="/search/quant-ph?searchtype=author&query=Babbush%2C+R">Ryan Babbush</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+L">Lin Lin</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="1909.00028v1-abstract-short" style="display: inline;"> Methods for electronic structure based on Gaussian and molecular orbital discretizations offer a well established, compact representation that forms much of the foundation of correlated quantum chemistry calculations on both classical and quantum computers. Despite their ability to describe essential physics with relatively few basis functions, these representations can suffer from a quartic growt… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.00028v1-abstract-full').style.display = 'inline'; document.getElementById('1909.00028v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1909.00028v1-abstract-full" style="display: none;"> Methods for electronic structure based on Gaussian and molecular orbital discretizations offer a well established, compact representation that forms much of the foundation of correlated quantum chemistry calculations on both classical and quantum computers. Despite their ability to describe essential physics with relatively few basis functions, these representations can suffer from a quartic growth of the number of integrals. Recent results have shown that, for some quantum and classical algorithms, moving to representations with diagonal two-body operators can result in dramatically lower asymptotic costs, even if the number of functions required increases significantly. We introduce a way to interpolate between the two regimes in a systematic and controllable manner, such that the number of functions is minimized while maintaining a block diagonal structure of the two-body operator and desirable properties of an original, primitive basis. Techniques are analyzed for leveraging the structure of this new representation on quantum computers. Empirical results for hydrogen chains suggest a scaling improvement from $O(N^{4.5})$ in molecular orbital representations to $O(N^{2.6})$ in our representation for quantum evolution in a fault-tolerant setting, and exhibit a constant factor crossover at 15 to 20 atoms. Moreover, we test these methods using modern density matrix renormalization group methods classically, and achieve excellent accuracy with respect to the complete basis set limit with a speedup of 1-2 orders of magnitude with respect to using the primitive or Gaussian basis sets alone. These results suggest our representation provides significant cost reductions while maintaining accuracy relative to molecular orbital or strictly diagonal approaches for modest-sized systems in both classical and quantum computation for correlated systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.00028v1-abstract-full').style.display = 'none'; document.getElementById('1909.00028v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 August, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1807.07470">arXiv:1807.07470</a> <span> [<a href="https://arxiv.org/pdf/1807.07470">pdf</a>, <a href="https://arxiv.org/format/1807.07470">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"> Machine learning study of the relationship between the geometric and entropy discord </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qin-Sheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xiao-Yu Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+M">Ming-Zheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+Y">Yi-Ming Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+H">Hao Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+S">Shao-Yi Wu</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="1807.07470v3-abstract-short" style="display: inline;"> As an important resource to realize quantum information, quantum correlation displays different behaviors, freezing phenomenon and non-localization, which are dissimilar to the entanglement and classical correlation, respectively. In our setup, the ordering of quantum correlation is represented for different quantization methods by considering an open quantum system scenario. The machine learning… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1807.07470v3-abstract-full').style.display = 'inline'; document.getElementById('1807.07470v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1807.07470v3-abstract-full" style="display: none;"> As an important resource to realize quantum information, quantum correlation displays different behaviors, freezing phenomenon and non-localization, which are dissimilar to the entanglement and classical correlation, respectively. In our setup, the ordering of quantum correlation is represented for different quantization methods by considering an open quantum system scenario. The machine learning method (neural network method) is then adopted to train for the construction of a bridge between the R猫nyi discord ($伪=2$) and the geometric discord (Bures distance) for $X$ form states. Our results clearly demonstrate that the machine learning method is useful for studying the differences and commonalities of different quantizing methods of quantum correlation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1807.07470v3-abstract-full').style.display = 'none'; document.getElementById('1807.07470v3-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 December, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 July, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2018. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1804.02791">arXiv:1804.02791</a> <span> [<a href="https://arxiv.org/pdf/1804.02791">pdf</a>, <a href="https://arxiv.org/ps/1804.02791">ps</a>, <a href="https://arxiv.org/format/1804.02791">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"> The freezing R猫nyi quantum discord </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xiao-Yu Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qin-Sheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+M">Ming-Zheng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+H">Hao Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+S">Shao-Yi Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+M">Ming-Chuan Zhu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1804.02791v1-abstract-short" style="display: inline;"> As a universal quantum character of quantum correlation, the freezing phenomenon is researched by geometry and quantum discord methods, respectively. In this paper, the properties of R`enyi discord is studied for two independent Dimer System coupled to two correlated Fermi-spin environments under the non-Markovian condition. We further demonstrate that the freezing behaviors still exist for R`enyi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.02791v1-abstract-full').style.display = 'inline'; document.getElementById('1804.02791v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1804.02791v1-abstract-full" style="display: none;"> As a universal quantum character of quantum correlation, the freezing phenomenon is researched by geometry and quantum discord methods, respectively. In this paper, the properties of R`enyi discord is studied for two independent Dimer System coupled to two correlated Fermi-spin environments under the non-Markovian condition. We further demonstrate that the freezing behaviors still exist for R`enyi discord and study the effects of different parameters on this behaviors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.02791v1-abstract-full').style.display = 'none'; document.getElementById('1804.02791v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 April, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 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/1712.01501">arXiv:1712.01501</a> <span> [<a href="https://arxiv.org/pdf/1712.01501">pdf</a>, <a href="https://arxiv.org/ps/1712.01501">ps</a>, <a href="https://arxiv.org/format/1712.01501">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/PhysRevA.97.063620">10.1103/PhysRevA.97.063620 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Generating scalable entanglement of ultracold bosons in superlattices through resonant shaking </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cao%2C+L">Lushuai Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+X">Xing Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qian-Ru Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+X">Xiao-Fan Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Fang%2C+X">Xue-Ting Fang</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+X">Xiang Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Schmelcher%2C+P">Peter Schmelcher</a>, <a href="/search/quant-ph?searchtype=author&query=Hu%2C+Z">Zhong-Kun 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="1712.01501v1-abstract-short" style="display: inline;"> Based on a one-dimensional double-well superlattice with a unit filling of ultracold atoms per site, we propose a scheme to generate scalable entangled states in the superlattice through resonant lattice shakings. Our scheme utilizes periodic lattice modulations to entangle two atoms in each unit cell with respect to their orbital degree of freedom, and the complete atomic system in the superlatti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1712.01501v1-abstract-full').style.display = 'inline'; document.getElementById('1712.01501v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1712.01501v1-abstract-full" style="display: none;"> Based on a one-dimensional double-well superlattice with a unit filling of ultracold atoms per site, we propose a scheme to generate scalable entangled states in the superlattice through resonant lattice shakings. Our scheme utilizes periodic lattice modulations to entangle two atoms in each unit cell with respect to their orbital degree of freedom, and the complete atomic system in the superlattice becomes a cluster of bipartite entangled atom pairs. To demonstrate this we perform $ab \ initio$ quantum dynamical simulations using the Multi-Layer Multi-Configuration Time-Dependent Hartree Method for Bosons, which accounts for all correlations among the atoms. The proposed clusters of bipartite entanglements manifest as an essential resource for various quantum applications, such as measurement based quantum computation. The lattice shaking scheme to generate this cluster possesses advantages such as a high scalability, fast processing speed, rich controllability on the target entangled states, and accessibility with current experimental techniques. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1712.01501v1-abstract-full').style.display = 'none'; document.getElementById('1712.01501v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 December, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A 97, 063620 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1512.03488">arXiv:1512.03488</a> <span> [<a href="https://arxiv.org/pdf/1512.03488">pdf</a>, <a href="https://arxiv.org/ps/1512.03488">ps</a>, <a href="https://arxiv.org/format/1512.03488">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/PhysRevE.90.052142">10.1103/PhysRevE.90.052142 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Re-examining the self-contained quantum refrigerator in the strong-coupling regime </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yu%2C+C">Chang-shui Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qing-yao Zhu</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="1512.03488v1-abstract-short" style="display: inline;"> We revisit the self-contained quantum refrigerator in the strong-internal-coupling regime by employing the quantum optical master equation. It is shown that strong internal coupling reduces the cooling ability of the refrigerator. In contrast to the weak-coupling case, strong internal coupling could lead to quite different and even converse thermodynamic behaviors. </span> <span class="abstract-full has-text-grey-dark mathjax" id="1512.03488v1-abstract-full" style="display: none;"> We revisit the self-contained quantum refrigerator in the strong-internal-coupling regime by employing the quantum optical master equation. It is shown that strong internal coupling reduces the cooling ability of the refrigerator. In contrast to the weak-coupling case, strong internal coupling could lead to quite different and even converse thermodynamic behaviors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1512.03488v1-abstract-full').style.display = 'none'; document.getElementById('1512.03488v1-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 December, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 6 figures, Physical Review E 90, 052142 (2014)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1507.00786">arXiv:1507.00786</a> <span> [<a href="https://arxiv.org/pdf/1507.00786">pdf</a>, <a href="https://arxiv.org/ps/1507.00786">ps</a>, <a href="https://arxiv.org/format/1507.00786">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/10.1088/0953-4075/49/1/015303">10.1088/0953-4075/49/1/015303 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Stationary states and quantum quench dynamics of Bose-Einstein condensates in a double-well potential </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wen%2C+L">Linghua Wen</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qizhong Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+T">Tianfu Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Jing%2C+X">Xili Jing</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+C">Chengshi 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="1507.00786v2-abstract-short" style="display: inline;"> We consider the properties of stationary states and the dynamics of Bose-Einstein condensates (BECs) in a double-well (DW) potential with pair tunneling by using a full quantum-mechanical treatment. Furthermore, we study the quantum quench dynamics of the DW system subjected to a sudden change of the Peierls phase. It is shown that strong pair tunneling evidently influences the energy spectrum str… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1507.00786v2-abstract-full').style.display = 'inline'; document.getElementById('1507.00786v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1507.00786v2-abstract-full" style="display: none;"> We consider the properties of stationary states and the dynamics of Bose-Einstein condensates (BECs) in a double-well (DW) potential with pair tunneling by using a full quantum-mechanical treatment. Furthermore, we study the quantum quench dynamics of the DW system subjected to a sudden change of the Peierls phase. It is shown that strong pair tunneling evidently influences the energy spectrum structure of the stationary states. For relatively weak repulsive interatomic interactions, the dynamics of the DW system with a maximal initial population difference evolves from Josephson oscillations to quantum self-trapping as one increases the pair tunneling strength, while for large repulsion the strong pair tunneling inhibits the quantum self-trapping. In the case of attractive interatomic interactions, strong pair tunneling tends to destroy the Josephson oscillations and quantum self-trapping, and the system eventually enters a symmetric regime of zero population difference. Finally, the effect of the Peierls phase on the quantum quench dynamics of the system is analyzed and discussed. These new features are remarkably different from the usual dynamical behaviors of a BEC in a DW potential. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1507.00786v2-abstract-full').style.display = 'none'; document.getElementById('1507.00786v2-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 November, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 July, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages,7 figures,accepted for publication in Journal of Physics B</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Journal of Physics B 49, 015303 (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1309.1391">arXiv:1309.1391</a> <span> [<a href="https://arxiv.org/pdf/1309.1391">pdf</a>, <a href="https://arxiv.org/ps/1309.1391">ps</a>, <a href="https://arxiv.org/format/1309.1391">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/10.1088/0256-307X/31/2/020301">10.1088/0256-307X/31/2/020301 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Quantum speed limit of a photon under non-Markovian dynamics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Z+Y">Z. Y. Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+S+Q">S. Q. Zhu</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="1309.1391v1-abstract-short" style="display: inline;"> Quantum speed limit (QSL) under noise has drawn considerable attention in real quantum computational processes and quantum communication. Though non-Markovian noise is proven to be able to accelerate quantum evolution for a damped Jaynes-Cummings model, in this work we show that non-Markovianity may even slow down the quantum evolution of an experimentally controllable photon system. As an importa… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1309.1391v1-abstract-full').style.display = 'inline'; document.getElementById('1309.1391v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1309.1391v1-abstract-full" style="display: none;"> Quantum speed limit (QSL) under noise has drawn considerable attention in real quantum computational processes and quantum communication. Though non-Markovian noise is proven to be able to accelerate quantum evolution for a damped Jaynes-Cummings model, in this work we show that non-Markovianity may even slow down the quantum evolution of an experimentally controllable photon system. As an important application, QSL time of a photon can be well controlled by regulating the relevant environment parameter properly, which is close to reach the currently available photonic experimental technology. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1309.1391v1-abstract-full').style.display = 'none'; document.getElementById('1309.1391v1-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, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 2 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Chin. Phys. Lett. 31, 020301 (2014) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1210.2505">arXiv:1210.2505</a> <span> [<a href="https://arxiv.org/pdf/1210.2505">pdf</a>, <a href="https://arxiv.org/ps/1210.2505">ps</a>, <a href="https://arxiv.org/format/1210.2505">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/PhysRevA.86.053609">10.1103/PhysRevA.86.053609 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measurement of phase fluctuations of Bose-Einstein condensates in an optical lattice </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+B">Bing Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qiang Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+H">Hailong Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Xiong%2C+D">Dezhi Xiong</a>, <a href="/search/quant-ph?searchtype=author&query=Xiong%2C+H">Hongwei Xiong</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+B">Baolong Lu</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="1210.2505v1-abstract-short" style="display: inline;"> Even at zero temperature, there exist phase fluctuations associated with an array of Bose-Einstein condensates confined in a one-dimensional optical lattice. We demonstrate a method to measure the phase fluctuations based on the Fourier spectrum of the atomic density for a condensate released from the optical lattice. The phase variance is extracted from the relative intensities of different peaks… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1210.2505v1-abstract-full').style.display = 'inline'; document.getElementById('1210.2505v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1210.2505v1-abstract-full" style="display: none;"> Even at zero temperature, there exist phase fluctuations associated with an array of Bose-Einstein condensates confined in a one-dimensional optical lattice. We demonstrate a method to measure the phase fluctuations based on the Fourier spectrum of the atomic density for a condensate released from the optical lattice. The phase variance is extracted from the relative intensities of different peaks in the Fourier spectrum. This method works even for high lattice strength where interference peaks disappear in the atomic density distribution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1210.2505v1-abstract-full').style.display = 'none'; document.getElementById('1210.2505v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 October, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2012. </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/1210.0182">arXiv:1210.0182</a> <span> [<a href="https://arxiv.org/pdf/1210.0182">pdf</a>, <a href="https://arxiv.org/ps/1210.0182">ps</a>, <a href="https://arxiv.org/format/1210.0182">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/10.1063/1.4771988">10.1063/1.4771988 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Quantum-memory-assisted entropic uncertainty relation with a single nitrogen-vacancy center in diamond </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Z+Y">Z. Y. Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+S+Q">S. Q. Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+W+L">W. L. Yang</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="1210.0182v2-abstract-short" style="display: inline;"> The limitation of simultaneous measurements of noncommuting observables can be eliminated when the measured particle is maximally entangled with a quantum memory. We present a proposal for testing this quantum-memory-assisted entropic uncertainty relation in a single nitrogen-vacancy (N-V) center in diamond only by local electronic measurements. As an application, this entropic uncertainty relatio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1210.0182v2-abstract-full').style.display = 'inline'; document.getElementById('1210.0182v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1210.0182v2-abstract-full" style="display: none;"> The limitation of simultaneous measurements of noncommuting observables can be eliminated when the measured particle is maximally entangled with a quantum memory. We present a proposal for testing this quantum-memory-assisted entropic uncertainty relation in a single nitrogen-vacancy (N-V) center in diamond only by local electronic measurements. As an application, this entropic uncertainty relation is used to witness entanglement between the electron and nuclear spins of the N-V center, which is close to the reach of currently available technology. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1210.0182v2-abstract-full').style.display = 'none'; document.getElementById('1210.0182v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 December, 2012; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 September, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2012. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">3 pages, 3 figures, published version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Appl. Phys. Lett. 101, 244105 (2012) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0811.4216">arXiv:0811.4216</a> <span> [<a href="https://arxiv.org/pdf/0811.4216">pdf</a>, <a href="https://arxiv.org/ps/0811.4216">ps</a>, <a href="https://arxiv.org/format/0811.4216">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"> Exact coherent matter-wave soliton induced and controlled by laser field </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hai%2C+W">Wenhua Hai</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Q">Qiongtao Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qianquan Zhu</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="0811.4216v2-abstract-short" style="display: inline;"> We find a set of exact solutions of coherent bright solitons in the quasi-one-dimensional (1D) Bose-Einstein condensate (BEC) trapped in a harmonic potential, by using a Gaussian laser well (barrier) with oscillating position to balance the repulsive (attractive) interatomic interaction. The bright solitons do not deform in propagation and are controlled accurately by the laser driving which res… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0811.4216v2-abstract-full').style.display = 'inline'; document.getElementById('0811.4216v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0811.4216v2-abstract-full" style="display: none;"> We find a set of exact solutions of coherent bright solitons in the quasi-one-dimensional (1D) Bose-Einstein condensate (BEC) trapped in a harmonic potential, by using a Gaussian laser well (barrier) with oscillating position to balance the repulsive (attractive) interatomic interaction. The bright solitons do not deform in propagation and are controlled accurately by the laser driving which resonates with the trapping potential. The solitonic motion is more stable for the repulsive BEC than that of the attractive BEC. The results reveal a different kind of soliton trains compared to that reported recently in Phys. Rev. Lett. 100, 164102 (2008) and suggest an experimental scheme for generating and controlling the coherent matter-wave solitons. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0811.4216v2-abstract-full').style.display = 'none'; document.getElementById('0811.4216v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 November, 2008; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 November, 2008; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2008. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 4figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0806.3806">arXiv:0806.3806</a> <span> [<a href="https://arxiv.org/pdf/0806.3806">pdf</a>, <a href="https://arxiv.org/ps/0806.3806">ps</a>, <a href="https://arxiv.org/format/0806.3806">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="Chaotic Dynamics">nlin.CD</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.79.023603">10.1103/PhysRevA.79.023603 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Chaotic shock waves of a Bose-Einstein condensate </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hai%2C+W">Wenhua Hai</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qianquan Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+S">Shiguang Rong</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="0806.3806v2-abstract-short" style="display: inline;"> It is demonstrated that the well-known Smale-horseshoe chaos exists in the time evolution of the one-dimensional Bose-Einstein condensate (BEC) driven by the time-periodic harmonic or inverted-harmonic potential. A formally exact solution of the time-dependent Gross-Pitaevskii equation is constructed, which describes the matter shock waves with chaotic or periodic amplitudes and phases. When the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0806.3806v2-abstract-full').style.display = 'inline'; document.getElementById('0806.3806v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0806.3806v2-abstract-full" style="display: none;"> It is demonstrated that the well-known Smale-horseshoe chaos exists in the time evolution of the one-dimensional Bose-Einstein condensate (BEC) driven by the time-periodic harmonic or inverted-harmonic potential. A formally exact solution of the time-dependent Gross-Pitaevskii equation is constructed, which describes the matter shock waves with chaotic or periodic amplitudes and phases. When the periodic driving is switched off and the number of condensed atoms is conserved, we obtained the exact stationary states and non-stationary states. The former contains the stable non-propagated shock wave, and in the latter the shock wave alternately collapses and grows for the harmonic trapping or propagates with exponentially increased shock-front speed for the antitrapping. It is revealed that existence of chaos play a role for suppressing the blast of matter wave. The results suggest a method for preparing the exponentially accelerated BEC shock waves or the stable stationary states. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0806.3806v2-abstract-full').style.display = 'none'; document.getElementById('0806.3806v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 February, 2009; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 June, 2008; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2008. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 1 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 79, 023603 (2009) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0804.0906">arXiv:0804.0906</a> <span> [<a href="https://arxiv.org/pdf/0804.0906">pdf</a>, <a href="https://arxiv.org/ps/0804.0906">ps</a>, <a href="https://arxiv.org/format/0804.0906">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/PhysRevE.80.016203">10.1103/PhysRevE.80.016203 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Controlling transition probability from matter-wave soliton to chaos </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qianquan Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Hai%2C+W">Wenhua Hai</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+S">Shiguang Rong</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="0804.0906v1-abstract-short" style="display: inline;"> For a Bose-Einstein condensate loaded into a weak traveling optical superlattice it is demonstrated that under a stochastic initial set and in a given parameter region the solitonic chaos appears with a certain probability. Effects of the lattice depths and wave vectors on the chaos probability are investigated analytically and numerically, and different chaotic regions associated with different… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0804.0906v1-abstract-full').style.display = 'inline'; document.getElementById('0804.0906v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0804.0906v1-abstract-full" style="display: none;"> For a Bose-Einstein condensate loaded into a weak traveling optical superlattice it is demonstrated that under a stochastic initial set and in a given parameter region the solitonic chaos appears with a certain probability. Effects of the lattice depths and wave vectors on the chaos probability are investigated analytically and numerically, and different chaotic regions associated with different chaos probabilities are found. The results suggest a feasible method for eliminating or strengthening chaos by modulating the moving superlattice experimentally. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0804.0906v1-abstract-full').style.display = 'none'; document.getElementById('0804.0906v1-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 April, 2008; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2008. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 2 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. E 80, 016203 (2009) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0705.0058">arXiv:0705.0058</a> <span> [<a href="https://arxiv.org/pdf/0705.0058">pdf</a>, <a href="https://arxiv.org/ps/0705.0058">ps</a>, <a href="https://arxiv.org/format/0705.0058">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/10.1088/0953-4075/41/9/095301">10.1088/0953-4075/41/9/095301 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Exact Floquet states of a driven condensate and their stabilities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hai%2C+W">Wenhua Hai</a>, <a href="/search/quant-ph?searchtype=author&query=Lee%2C+C">Chaohong Lee</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+Q">Qianquan Zhu</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="0705.0058v2-abstract-short" style="display: inline;"> We investigate the Gross-Pitaevskii equation for a classically chaotic system, which describes an atomic Bose-Einstein condensate confined in an optical lattice and driven by a spatiotemporal periodic laser field. It is demonstrated that the exact Floquet states appear when the external time-dependent potential is balanced by the nonlinear mean-field interaction. The balance region of parameters… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0705.0058v2-abstract-full').style.display = 'inline'; document.getElementById('0705.0058v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0705.0058v2-abstract-full" style="display: none;"> We investigate the Gross-Pitaevskii equation for a classically chaotic system, which describes an atomic Bose-Einstein condensate confined in an optical lattice and driven by a spatiotemporal periodic laser field. It is demonstrated that the exact Floquet states appear when the external time-dependent potential is balanced by the nonlinear mean-field interaction. The balance region of parameters is divided into a phase-continuing region and a phase-jumping one. In the latter region, the Floquet states are spatiotemporal vortices of nontrivial phase structures and zero-density cores. Due to the velocity singularities of vortex cores and the blowing-up of perturbed solutions, the spatiotemporal vortices are unstable periodic states embedded in chaos. The stability and instability of these Floquet states are numerically explored by the time evolution of fidelity between the exact and numerical solutions. It is numerically illustrated that the stable Floquet states could be prepared from the uniformly initial states by slow growth of the external potential. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0705.0058v2-abstract-full').style.display = 'none'; document.getElementById('0705.0058v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 April, 2008; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 April, 2007; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2007. </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, 3 eps figures, final version accepted for publication in J. Phys. B</span> </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" aria-label="Secondary">  <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/about">About</a></li> <li><a href="https://info.arxiv.org/help">Help</a></li> </ul> </div> <div class="column"> <ul class="nav-spaced"> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>contact arXiv</title><desc>Click here to contact arXiv</desc><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg> <a href="https://info.arxiv.org/help/contact.html"> Contact</a> </li> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>subscribe to arXiv mailings</title><desc>Click here to subscribe</desc><path d="M476 3.2L12.5 270.6c-18.1 10.4-15.8 35.6 2.2 43.2L121 358.4l287.3-253.2c5.5-4.9 13.3 2.6 8.6 8.3L176 407v80.5c0 23.6 28.5 32.9 42.5 15.8L282 426l124.6 52.2c14.2 6 30.4-2.9 33-18.2l72-432C515 7.8 493.3-6.8 476 3.2z"/></svg> <a href="https://info.arxiv.org/help/subscribe"> Subscribe</a> </li> </ul> </div> </div> </div>   <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/license/index.html">Copyright</a></li> <li><a href="https://info.arxiv.org/help/policies/privacy_policy.html">Privacy Policy</a></li> </ul> </div> <div class="column sorry-app-links"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/web_accessibility.html">Web Accessibility Assistance</a></li> <li> <p class="help"> <a class="a11y-main-link" href="https://status.arxiv.org" target="_blank">arXiv Operational Status <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 256 512" class="icon filter-dark_grey" role="presentation"><path d="M224.3 273l-136 136c-9.4 9.4-24.6 9.4-33.9 0l-22.6-22.6c-9.4-9.4-9.4-24.6 0-33.9l96.4-96.4-96.4-96.4c-9.4-9.4-9.4-24.6 0-33.9L54.3 103c9.4-9.4 24.6-9.4 33.9 0l136 136c9.5 9.4 9.5 24.6.1 34z"/></svg></a><br> Get status notifications via <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/email/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg>email</a> or <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/slack/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512" class="icon filter-black" role="presentation"><path d="M94.12 315.1c0 25.9-21.16 47.06-47.06 47.06S0 341 0 315.1c0-25.9 21.16-47.06 47.06-47.06h47.06v47.06zm23.72 0c0-25.9 21.16-47.06 47.06-47.06s47.06 21.16 47.06 47.06v117.84c0 25.9-21.16 47.06-47.06 47.06s-47.06-21.16-47.06-47.06V315.1zm47.06-188.98c-25.9 0-47.06-21.16-47.06-47.06S139 32 164.9 32s47.06 21.16 47.06 47.06v47.06H164.9zm0 23.72c25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06H47.06C21.16 243.96 0 222.8 0 196.9s21.16-47.06 47.06-47.06H164.9zm188.98 47.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06h-47.06V196.9zm-23.72 0c0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06V79.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06V196.9zM283.1 385.88c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06v-47.06h47.06zm0-23.72c-25.9 0-47.06-21.16-47.06-47.06 0-25.9 21.16-47.06 47.06-47.06h117.84c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06H283.1z"/></svg>slack</a> </p> </li> </ul> </div> </div> </div>  </div> </footer> <script src="https://static.arxiv.org/static/base/1.0.0a5/js/member_acknowledgement.js"></script> </body> </html>

CINXE.COM

Search | arXiv e-print repository