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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="Fu, Y"> <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/2411.09390">arXiv:2411.09390</a> <span> [<a href="https://arxiv.org/pdf/2411.09390">pdf</a>, <a href="https://arxiv.org/format/2411.09390">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="High Energy Physics - Theory">hep-th</span> </div> </div> <p class="title is-5 mathjax"> Statistics and Complexity of Wavefunction Spreading in Quantum Dynamical Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yichao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Kim%2C+K">Keun-Young Kim</a>, <a href="/search/quant-ph?searchtype=author&query=Pal%2C+K">Kunal Pal</a>, <a href="/search/quant-ph?searchtype=author&query=Pal%2C+K">Kuntal Pal</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.09390v1-abstract-short" style="display: inline;"> We consider the statistics of the results of a measurement of the spreading operator in the Krylov basis generated by the Hamiltonian of a quantum system starting from a specified initial pure state. We first obtain the probability distribution of the results of measurements of this spreading operator at a certain instant of time, and compute the characteristic function of this distribution. We sh… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09390v1-abstract-full').style.display = 'inline'; document.getElementById('2411.09390v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.09390v1-abstract-full" style="display: none;"> We consider the statistics of the results of a measurement of the spreading operator in the Krylov basis generated by the Hamiltonian of a quantum system starting from a specified initial pure state. We first obtain the probability distribution of the results of measurements of this spreading operator at a certain instant of time, and compute the characteristic function of this distribution. We show that the moments of this characteristic function are related to the so-called generalised spread complexities, and obtain expressions for them in several cases when the Hamiltonian is an element of a Lie algebra. Furthermore, by considering a continuum limit of the Krylov basis, we show that the generalised spread complexities of higher orders have a peak in the time evolution for a random matrix Hamiltonian belonging to the Gaussian unitary ensemble. We also obtain an upper bound in the change in generalised spread complexity at an arbitrary time in terms of the operator norm of the Hamiltonian and discuss the significance of these results. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09390v1-abstract-full').style.display = 'none'; document.getElementById('2411.09390v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.01538">arXiv:2411.01538</a> <span> [<a href="https://arxiv.org/pdf/2411.01538">pdf</a>, <a href="https://arxiv.org/format/2411.01538">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"> Observation of freezing phenomenon in high-dimensional quantum correlation dynamics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yue Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wenquan Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yunhan Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Duan%2C+C">Chang-Kui Duan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+B">Bo Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yeliang Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+X">Xing 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="2411.01538v1-abstract-short" style="display: inline;"> Quantum information processing (QIP) based on high-dimensional quantum systems provides unique advantages and new potentials where high-dimensional quantum correlations (QCs) play vital roles. Exploring the resistance of QCs against noises is crucial as QCs are fragile due to complex and unavoidable system-environment interactions. In this study, we investigate the performance of high-dimensional… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.01538v1-abstract-full').style.display = 'inline'; document.getElementById('2411.01538v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.01538v1-abstract-full" style="display: none;"> Quantum information processing (QIP) based on high-dimensional quantum systems provides unique advantages and new potentials where high-dimensional quantum correlations (QCs) play vital roles. Exploring the resistance of QCs against noises is crucial as QCs are fragile due to complex and unavoidable system-environment interactions. In this study, we investigate the performance of high-dimensional QCs under local dephasing noise using a single nitrogen-vacancy center in diamond. A freezing phenomenon in the high-dimensional quantum discord dynamics was observed, showing discord is robust against local dephasing noise. Utilizing a robustness metric known as freezing index, we found that the discord of qutrits outperforms their qubits counterpart when confronted with dephasing noise. Furthermore, we developed a geometric picture to explain this intriguing freezing phenomenon phenomenon. Our findings highlight the potential of utilizing discord as a physical resource for advancing QIP in high-dimensional quantum settings. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.01538v1-abstract-full').style.display = 'none'; document.getElementById('2411.01538v1-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 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.16462">arXiv:2407.16462</a> <span> [<a href="https://arxiv.org/pdf/2407.16462">pdf</a>, <a href="https://arxiv.org/format/2407.16462">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OL.527857">10.1364/OL.527857 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Source-independent quantum secret sharing with entangled photon pair networks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xiao%2C+Y">Yi-Ran Xiao</a>, <a href="/search/quant-ph?searchtype=author&query=Jia%2C+Z">Zhao-Ying Jia</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+Y">Yu-Chen Song</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Y">Yu Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2407.16462v1-abstract-short" style="display: inline;"> The large-scale deployment of quantum secret sharing (QSS) in quantum networks is currently challenging due to the requirements for the generation and distribution of multipartite entanglement states. Here we present an efficient source-independent QSS protocol utilizing entangled photon pairs in quantum networks. Through the post-matching method, which means the measurement events in the same bas… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.16462v1-abstract-full').style.display = 'inline'; document.getElementById('2407.16462v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.16462v1-abstract-full" style="display: none;"> The large-scale deployment of quantum secret sharing (QSS) in quantum networks is currently challenging due to the requirements for the generation and distribution of multipartite entanglement states. Here we present an efficient source-independent QSS protocol utilizing entangled photon pairs in quantum networks. Through the post-matching method, which means the measurement events in the same basis are matched, the key rate is almost independent of the number of participants. In addition, the unconditional security of our QSS against internal and external eavesdroppers can be proved by introducing an equivalent virtual protocol. Our protocol has great performance and technical advantages in future quantum networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.16462v1-abstract-full').style.display = 'none'; document.getElementById('2407.16462v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 9 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Optics Letters 49, 4210 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.15954">arXiv:2407.15954</a> <span> [<a href="https://arxiv.org/pdf/2407.15954">pdf</a>, <a href="https://arxiv.org/format/2407.15954">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> </div> </div> <p class="title is-5 mathjax"> Residue imaginary velocity induces many-body delocalization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hu%2C+S">Shi-Xin Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yong-Xu Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yi Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2407.15954v1-abstract-short" style="display: inline;"> Localization and delocalization are historic topics central to quantum and condensed matter physics. We discover a new delocalization mechanism attributed to a residue imaginary (part of) velocity $\operatorname{Im}(v)$, feasible for ground states or low-temperature states of non-Hermitian quantum systems under periodic boundary conditions. Interestingly, a disorder field contributing to… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.15954v1-abstract-full').style.display = 'inline'; document.getElementById('2407.15954v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.15954v1-abstract-full" style="display: none;"> Localization and delocalization are historic topics central to quantum and condensed matter physics. We discover a new delocalization mechanism attributed to a residue imaginary (part of) velocity $\operatorname{Im}(v)$, feasible for ground states or low-temperature states of non-Hermitian quantum systems under periodic boundary conditions. Interestingly, a disorder field contributing to $\operatorname{Im}(v)$ may allow strong-disorder-limit delocalization when $\operatorname{Im}(v)$ prevails over the Anderson localization. We demonstrate such delocalization with correlation and entanglement behaviors, as well as its many-body nature and generalizability to finite temperatures and interactions. Thus, the nontrivial physics of $\operatorname{Im}(v)$ significantly enriches our understanding of delocalization and breeds useful applications, e.g., in quantum adiabatic processes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.15954v1-abstract-full').style.display = 'none'; document.getElementById('2407.15954v1-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 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.00897">arXiv:2407.00897</a> <span> [<a href="https://arxiv.org/pdf/2407.00897">pdf</a>, <a href="https://arxiv.org/format/2407.00897">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"> Multi-field quantum conferencing overcomes the network capacity limit </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Y">Yu-Shuo Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2407.00897v1-abstract-short" style="display: inline;"> Quantum conferencing enables multiple nodes within a quantum network to share a secure group key for private message broadcasting. The key rate, however, is limited by the repeaterless capacity to distribute multiparticle entangled states across the network. Currently, in the finite-size regime, no feasible schemes utilizing existing experimental techniques can overcome the fundamental rate-distan… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.00897v1-abstract-full').style.display = 'inline'; document.getElementById('2407.00897v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.00897v1-abstract-full" style="display: none;"> Quantum conferencing enables multiple nodes within a quantum network to share a secure group key for private message broadcasting. The key rate, however, is limited by the repeaterless capacity to distribute multiparticle entangled states across the network. Currently, in the finite-size regime, no feasible schemes utilizing existing experimental techniques can overcome the fundamental rate-distance limit of quantum conferencing in quantum networks without repeaters. Here, we propose a practical, multi-field scheme that breaks this limit, involving virtually establishing Greenberger-Horne-Zeilinger states through post-measurement coincidence matching. This proposal features a measurement-device-independent characteristic and can directly scale to support any number of users. Simulations show that the fundamental limitation on the group key rate can be overcome in a reasonable running time of sending $10^{14}$ pulses. We predict that it offers an efficient design for long-distance broadcast communication in future quantum networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.00897v1-abstract-full').style.display = 'none'; document.getElementById('2407.00897v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 June, 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">20 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.17267">arXiv:2406.17267</a> <span> [<a href="https://arxiv.org/pdf/2406.17267">pdf</a>, <a href="https://arxiv.org/format/2406.17267">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.527862">10.1364/OE.527862 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Efficient source-independent quantum conference key agreement </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Y">Yu Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Xiao%2C+Y">Yi-Ran Xiao</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+Y">Yu-Chen Song</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+X">Xiao-Yu Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2406.17267v1-abstract-short" style="display: inline;"> Quantum conference key agreement (QCKA) enables the unconditional secure distribution of conference keys among multiple participants. Due to challenges in high-fidelity preparation and long-distance distribution of multi-photon entanglement, entanglement-based QCKA is facing severe limitations in both key rate and scalability. Here, we propose a source-independent QCKA scheme utilizing the post-ma… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.17267v1-abstract-full').style.display = 'inline'; document.getElementById('2406.17267v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.17267v1-abstract-full" style="display: none;"> Quantum conference key agreement (QCKA) enables the unconditional secure distribution of conference keys among multiple participants. Due to challenges in high-fidelity preparation and long-distance distribution of multi-photon entanglement, entanglement-based QCKA is facing severe limitations in both key rate and scalability. Here, we propose a source-independent QCKA scheme utilizing the post-matching method, feasible within the entangled photon pair distribution network. We introduce an equivalent distributing virtual multi-photon entanglement protocol for providing the unconditional security proof even in the case of coherent attacks. For the symmetry star-network, comparing with previous $n$-photon entanglement protocol, the conference key rate is improved from $O(畏^{n})$ to $O(畏^{2})$, where $畏$ is the transmittance from the entanglement source to one participant. Simulation results show that the performance of our protocol has multiple orders of magnitude advantages in the intercity distance. We anticipate that our approach will demonstrate its potential in the implementation of quantum networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.17267v1-abstract-full').style.display = 'none'; document.getElementById('2406.17267v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Optics Express 32, 24629 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.15853">arXiv:2406.15853</a> <span> [<a href="https://arxiv.org/pdf/2406.15853">pdf</a>, <a href="https://arxiv.org/format/2406.15853">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"> Repeater-Like Asynchronous Measurement-Device-Independent Quantum Conference Key Agreement </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Y">Yu-Shuo Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2406.15853v1-abstract-short" style="display: inline;"> Quantum conference key agreement facilitates secure communication among multiple parties through multipartite entanglement and is anticipated to be an important cryptographic primitive for future quantum networks. However, the experimental complexity and low efficiency associated with the synchronous detection of multipartite entangled states have significantly hindered their practical application… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.15853v1-abstract-full').style.display = 'inline'; document.getElementById('2406.15853v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.15853v1-abstract-full" style="display: none;"> Quantum conference key agreement facilitates secure communication among multiple parties through multipartite entanglement and is anticipated to be an important cryptographic primitive for future quantum networks. However, the experimental complexity and low efficiency associated with the synchronous detection of multipartite entangled states have significantly hindered their practical application. In this work, we propose a measurement-device-independent conference key agreement protocol that utilizes asynchronous Greenberger-Horne-Zeilinger state measurement.This approach achieves a linear scaling of the conference key rate among multiple parties, exhibiting performance similar to that of the single-repeater scheme in quantum networks. The asynchronous measurement strategy bypasses the need for complex global phase locking technologies, concurrently extending the intercity transmission distance with composable security in the finite key regime. Additionally, our work also showcases the advantages of the asynchronous pairing concept in multiparty quantum entanglement. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.15853v1-abstract-full').style.display = 'none'; document.getElementById('2406.15853v1-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 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 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/2406.03365">arXiv:2406.03365</a> <span> [<a href="https://arxiv.org/pdf/2406.03365">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Optical read and write of spin states in organic diradicals </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Chowdhury%2C+R">Rituparno Chowdhury</a>, <a href="/search/quant-ph?searchtype=author&query=Murto%2C+P">Petri Murto</a>, <a href="/search/quant-ph?searchtype=author&query=Panjwani%2C+N+A">Naitik A. Panjwani</a>, <a href="/search/quant-ph?searchtype=author&query=Sun%2C+Y">Yan Sun</a>, <a href="/search/quant-ph?searchtype=author&query=Ghosh%2C+P">Pratyush Ghosh</a>, <a href="/search/quant-ph?searchtype=author&query=Boeije%2C+Y">Yorrick Boeije</a>, <a href="/search/quant-ph?searchtype=author&query=Derkach%2C+V">Vadim Derkach</a>, <a href="/search/quant-ph?searchtype=author&query=Woo%2C+S">Seung-Je Woo</a>, <a href="/search/quant-ph?searchtype=author&query=Millington%2C+O">Oliver Millington</a>, <a href="/search/quant-ph?searchtype=author&query=Congrave%2C+D+G">Daniel G. Congrave</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Mustafa%2C+T+B+E">Tarig B. E. Mustafa</a>, <a href="/search/quant-ph?searchtype=author&query=Monteverde%2C+M">Miguel Monteverde</a>, <a href="/search/quant-ph?searchtype=author&query=Cerd%C3%A1%2C+J">Jes煤s Cerd谩</a>, <a href="/search/quant-ph?searchtype=author&query=Behrends%2C+J">Jan Behrends</a>, <a href="/search/quant-ph?searchtype=author&query=Rao%2C+A">Akshay Rao</a>, <a href="/search/quant-ph?searchtype=author&query=Beljonne%2C+D">David Beljonne</a>, <a href="/search/quant-ph?searchtype=author&query=Chepelianskii%2C+A">Alexei Chepelianskii</a>, <a href="/search/quant-ph?searchtype=author&query=Bronstein%2C+H">Hugo Bronstein</a>, <a href="/search/quant-ph?searchtype=author&query=Friend%2C+R+H">Richard H. Friend</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.03365v1-abstract-short" style="display: inline;"> Optical control and read-out of the ground state spin structure has been demonstrated for defect states in crystalline semiconductors, including the diamond NV- center, and these are promising systems for quantum technologies. Molecular organic semiconductors offer synthetic control of spin placement, in contrast to current limitations in these crystalline systems. Here we report the discovery of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.03365v1-abstract-full').style.display = 'inline'; document.getElementById('2406.03365v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.03365v1-abstract-full" style="display: none;"> Optical control and read-out of the ground state spin structure has been demonstrated for defect states in crystalline semiconductors, including the diamond NV- center, and these are promising systems for quantum technologies. Molecular organic semiconductors offer synthetic control of spin placement, in contrast to current limitations in these crystalline systems. Here we report the discovery of spin-optical addressability in a diradical molecule that comprises two trityl radical groups coupled via a fluorene bridge. We demonstrate the three important properties that enable operation as a spin-photon interface: (i) triplet and singlet spin states show photoluminescence peaked at 640 and 700 nm respectively; this allows easy optical measurement of ground state spin. (ii) the ground state spin exchange is small (~60 渭eV) that allows preparation of ground state spin population. This can be achieved by spin-selective excited state intersystem crossing, and we report up to 8% microwave-driven contrast in photoluminescence. (iii) both singlet and triplet manifolds have near-unity photoluminescence quantum yield, which is in contrast to the near-zero quantum yields in prior reports of molecular diradicals. Our results establish these tuneable open-shell organic molecules as a platform to engineer tailor-made spin-optical interfaces. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.03365v1-abstract-full').style.display = 'none'; document.getElementById('2406.03365v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.15144">arXiv:2405.15144</a> <span> [<a href="https://arxiv.org/pdf/2405.15144">pdf</a>, <a href="https://arxiv.org/format/2405.15144">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="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Ultra-sensitive solid-state organic molecular microwave quantum receiver </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+B">Bo Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Han%2C+Y">Yuchen Han</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+H">Hong-Liang Wu</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+S">Shuo Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Oxborrow%2C+M">Mark Oxborrow</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Q">Qing Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yue Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+W">Weibin Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yeliang Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+D">Dezhi Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Jun Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.15144v1-abstract-short" style="display: inline;"> High-accuracy microwave sensing is widely demanded in various fields, ranging from cosmology to microwave quantum technology. Quantum receivers based on inorganic solid-state spin systems are promising candidates for such purpose because of the stability and compatibility, but their best sensitivity is currently limited to a few pT/$\sqrt{\rm{Hz}}$. Here, by utilising an enhanced readout scheme wi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.15144v1-abstract-full').style.display = 'inline'; document.getElementById('2405.15144v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.15144v1-abstract-full" style="display: none;"> High-accuracy microwave sensing is widely demanded in various fields, ranging from cosmology to microwave quantum technology. Quantum receivers based on inorganic solid-state spin systems are promising candidates for such purpose because of the stability and compatibility, but their best sensitivity is currently limited to a few pT/$\sqrt{\rm{Hz}}$. Here, by utilising an enhanced readout scheme with the state-of-the-art solid-state maser technology, we develop a robust microwave quantum receiver functioned by organic molecular spins at ambient conditions. Owing to the maser amplification, the sensitivity of the receiver achieves 6.14 $\pm$ 0.17 fT/$\sqrt{\rm{Hz}}$ which exceeds three orders of magnitude than that of the inorganic solid-state quantum receivers. The heterodyne detection without additional local oscillators improves bandwidth of the receiver and allows frequency detection. The scheme can be extended to other solid-state spin systems without complicated control pulses and thus enables practical applications such as electron spin resonance spectroscopy, dark matter searches, and astronomical observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.15144v1-abstract-full').style.display = 'none'; document.getElementById('2405.15144v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 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/2404.17463">arXiv:2404.17463</a> <span> [<a href="https://arxiv.org/pdf/2404.17463">pdf</a>, <a href="https://arxiv.org/format/2404.17463">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.528683">10.1364/OE.528683 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Superresolution imaging of two incoherent optical sources with unequal brightnesses </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Jian-Dong Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yiwen Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Hou%2C+L">Lili Hou</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Shuai Wang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.17463v1-abstract-short" style="display: inline;"> Resolving the separation between two incoherent optical sources with high precision is of great significance for fluorescence imaging and astronomical observations. In this paper, we focus on a more general scenario where two sources have unequal brightnesses. We give the ultimate precision limit with respect to separation by using the quantum Fisher information. Through the calculation of the cla… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.17463v1-abstract-full').style.display = 'inline'; document.getElementById('2404.17463v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.17463v1-abstract-full" style="display: none;"> Resolving the separation between two incoherent optical sources with high precision is of great significance for fluorescence imaging and astronomical observations. In this paper, we focus on a more general scenario where two sources have unequal brightnesses. We give the ultimate precision limit with respect to separation by using the quantum Fisher information. Through the calculation of the classical Fisher information, we analyze and compare several specific measurement schemes including direct measurement, Gaussian mode measurement and zero-photon measurement. The results indicate that Gaussian mode measurement is the nearly optimal for a small separation. Our work provides a positive complement to the aspect of superresolution imaging of incoherent sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.17463v1-abstract-full').style.display = 'none'; document.getElementById('2404.17463v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Opt. Express 32, 26147-26156 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.10110">arXiv:2309.10110</a> <span> [<a href="https://arxiv.org/pdf/2309.10110">pdf</a>, <a href="https://arxiv.org/format/2309.10110">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Fluid Dynamics">physics.flu-dyn</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/PhysRevResearch.6.023273">10.1103/PhysRevResearch.6.023273 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Topological modes and spectral flows in inhomogeneous PT-symmetric continuous media </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yichen Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Qin%2C+H">Hong Qin</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.10110v2-abstract-short" style="display: inline;"> In classical Hermitian continuous media, the spectral-flow index of topological modes is linked to the bulk topology via index theorem. However, the interface between two bulks is usually non-Hermitian due to the inhomogeneities of system parameters. We show that the connection between topological modes and bulk topology still exists despite the non-Hermiticity at the interface if the system is en… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.10110v2-abstract-full').style.display = 'inline'; document.getElementById('2309.10110v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.10110v2-abstract-full" style="display: none;"> In classical Hermitian continuous media, the spectral-flow index of topological modes is linked to the bulk topology via index theorem. However, the interface between two bulks is usually non-Hermitian due to the inhomogeneities of system parameters. We show that the connection between topological modes and bulk topology still exists despite the non-Hermiticity at the interface if the system is endowed with PT symmetry. The theoretical framework developed is applied to the Hall magnetohydrodynamic model to identify a topological mode called topological Alfv茅n-sound wave in magnetized plasmas. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.10110v2-abstract-full').style.display = 'none'; document.getElementById('2309.10110v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Research 6, 023273 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.08821">arXiv:2308.08821</a> <span> [<a href="https://arxiv.org/pdf/2308.08821">pdf</a>, <a href="https://arxiv.org/format/2308.08821">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1126/sciadv.adk3258">10.1126/sciadv.adk3258 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental quantum e-commerce </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cao%2C+X">Xiao-Yu Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+B">Bing-Hong Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yang Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2308.08821v2-abstract-short" style="display: inline;"> E-commerce, a type of trading that occurs at a high frequency on the Internet, requires guaranteeing the integrity, authentication and non-repudiation of messages through long distance. As current e-commerce schemes are vulnerable to computational attacks, quantum cryptography, ensuring information-theoretic security against adversary's repudiation and forgery, provides a solution to this problem.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.08821v2-abstract-full').style.display = 'inline'; document.getElementById('2308.08821v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.08821v2-abstract-full" style="display: none;"> E-commerce, a type of trading that occurs at a high frequency on the Internet, requires guaranteeing the integrity, authentication and non-repudiation of messages through long distance. As current e-commerce schemes are vulnerable to computational attacks, quantum cryptography, ensuring information-theoretic security against adversary's repudiation and forgery, provides a solution to this problem. However, quantum solutions generally have much lower performance compared to classical ones. Besides, when considering imperfect devices, the performance of quantum schemes exhibits a significant decline. Here, for the first time, we demonstrate the whole e-commerce process of involving the signing of a contract and payment among three parties by proposing a quantum e-commerce scheme, which shows resistance of attacks from imperfect devices. Results show that with a maximum attenuation of 25 dB among participants, our scheme can achieve a signature rate of 0.82 times per second for an agreement size of approximately 0.428 megabit. This proposed scheme presents a promising solution for providing information-theoretic security for e-commerce. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.08821v2-abstract-full').style.display = 'none'; document.getElementById('2308.08821v2-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 5 figures, 5 tables</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science Advances 10, eadk3258 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.01260">arXiv:2307.01260</a> <span> [<a href="https://arxiv.org/pdf/2307.01260">pdf</a>, <a href="https://arxiv.org/format/2307.01260">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevB.108.245114">10.1103/PhysRevB.108.245114 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Nontrivial worldline winding in non-Hermitian quantum systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hu%2C+S">Shi-Xin Hu</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yongxu Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yi Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.01260v2-abstract-short" style="display: inline;"> Amid the growing interest in non-Hermitian quantum systems, non-interacting models have received the most attention. Here, through the stochastic series expansion quantum Monte Carlo method, we investigate non-Hermitian physics in interacting quantum systems, e.g., various non-Hermitian quantum spin chains. While calculations yield consistent numerical results under open boundary conditions, non-H… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.01260v2-abstract-full').style.display = 'inline'; document.getElementById('2307.01260v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.01260v2-abstract-full" style="display: none;"> Amid the growing interest in non-Hermitian quantum systems, non-interacting models have received the most attention. Here, through the stochastic series expansion quantum Monte Carlo method, we investigate non-Hermitian physics in interacting quantum systems, e.g., various non-Hermitian quantum spin chains. While calculations yield consistent numerical results under open boundary conditions, non-Hermitian quantum systems under periodic boundary conditions observe an unusual concentration of imaginary-time worldlines over nontrivial winding and require enhanced ergodicity between winding-number sectors for proper convergences. Such nontrivial worldline winding is an emergent physical phenomenon that also exists in other non-Hermitian models and analytical approaches. Alongside the non-Hermitian skin effect and the point-gap spectroscopy, it largely extends the identification and analysis of non-Hermitian topological phenomena to quantum systems with interactions, finite temperatures, biorthogonal basis, and periodic boundary conditions in a novel and controlled fashion. Finally, we study the direct physical implications of such nontrivial worldline winding, which bring additional, potentially quasi-long-range contributions to the entanglement entropy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.01260v2-abstract-full').style.display = 'none'; document.getElementById('2307.01260v2-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 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> Physical Review B, 108, 245114(2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.04569">arXiv:2304.04569</a> <span> [<a href="https://arxiv.org/pdf/2304.04569">pdf</a>, <a href="https://arxiv.org/ps/2304.04569">ps</a>, <a href="https://arxiv.org/format/2304.04569">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OL.491511">10.1364/OL.491511 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Asynchronous measurement-device-independent quantum key distribution with hybrid source </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Bai%2C+J">Jun-Lin Bai</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2304.04569v3-abstract-short" style="display: inline;"> The linear constraint of secret key rate capacity is overcome by the tiwn-field quantum key distribution (QKD). However, the complex phase-locking and phase-tracking technique requirements throttle the real-life applications of twin-field protocol. The asynchronous measurement-device-independent (AMDI) QKD or called mode-pairing QKD protocol can relax the technical requirements and keep the simila… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.04569v3-abstract-full').style.display = 'inline'; document.getElementById('2304.04569v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.04569v3-abstract-full" style="display: none;"> The linear constraint of secret key rate capacity is overcome by the tiwn-field quantum key distribution (QKD). However, the complex phase-locking and phase-tracking technique requirements throttle the real-life applications of twin-field protocol. The asynchronous measurement-device-independent (AMDI) QKD or called mode-pairing QKD protocol can relax the technical requirements and keep the similar performance of twin-field protocol. Here, we propose an AMDI-QKD protocol with a nonclassical light source by changing the phase-randomized weak coherent state to a phase-randomized coherent-state superposition in the signal state time window. Simulation results show that our proposed hybrid source protocol significantly enhances the key rate of the AMDI-QKD protocol, while exhibiting robustness to imperfect modulation of nonclassical light sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.04569v3-abstract-full').style.display = 'none'; document.getElementById('2304.04569v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Opt. Lett. 48, 3551 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.14622">arXiv:2303.14622</a> <span> [<a href="https://arxiv.org/pdf/2303.14622">pdf</a>, <a href="https://arxiv.org/ps/2303.14622">ps</a>, <a href="https://arxiv.org/format/2303.14622">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> </div> <div 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/10.1007/s11433-023-2105-7">10.1007/s11433-023-2105-7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental quantum secret sharing based on phase encoding of coherent states </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Shen%2C+A">Ao Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+X">Xiao-Yu Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yang Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Gu%2C+J">Jie Gu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wen-Bo Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Weng%2C+C">Chen-Xun Weng</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2303.14622v2-abstract-short" style="display: inline;"> Quantum secret sharing (QSS) is one of the basic communication primitives in future quantum networks which addresses part of the basic cryptographic tasks of multiparty communication and computation. Nevertheless, it is a challenge to provide a practical QSS protocol with security against general attacks. A QSS protocol that balances security and practicality is still lacking. Here, we propose a Q… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.14622v2-abstract-full').style.display = 'inline'; document.getElementById('2303.14622v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.14622v2-abstract-full" style="display: none;"> Quantum secret sharing (QSS) is one of the basic communication primitives in future quantum networks which addresses part of the basic cryptographic tasks of multiparty communication and computation. Nevertheless, it is a challenge to provide a practical QSS protocol with security against general attacks. A QSS protocol that balances security and practicality is still lacking. Here, we propose a QSS protocol with simple phase encoding of coherent states among three parties. Removing the requirement of impractical entangled resources and the need for phase randomization, our protocol can be implemented with accessible technology. We provide the finite-key analysis against coherent attacks and implement a proof-of-principle experiment to demonstrate our scheme's feasibility. Our scheme achieves a key rate of 85.3 bps under a 35 dB channel loss. Combined with security against general attacks and accessible technology, our protocol is a promising candidate for practical multiparty quantum communication networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.14622v2-abstract-full').style.display = 'none'; document.getElementById('2303.14622v2-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 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 5 figures, 3 tables, accepted by Sci. China-Phys. Mech. Astron</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Sci. China-Phys. Mech. Astron. 66, 260311 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.11585">arXiv:2303.11585</a> <span> [<a href="https://arxiv.org/pdf/2303.11585">pdf</a>, <a href="https://arxiv.org/ps/2303.11585">ps</a>, <a href="https://arxiv.org/format/2303.11585">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevApplied.20.024046">10.1103/PhysRevApplied.20.024046 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Phase-Matching Quantum Key Distribution without Intensity Modulation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Shao%2C+S">Shan-Feng Shao</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+X">Xiao-Yu Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Gu%2C+J">Jie Gu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wen-Bo Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2303.11585v3-abstract-short" style="display: inline;"> Quantum key distribution provides a promising solution for sharing secure keys between two distant parties with unconditional security. Nevertheless, quantum key distribution is still severely threatened by the imperfections of devices. In particular, the classical pulse correlation threatens security when sending decoy states. To address this problem and simplify experimental requirements, we pro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.11585v3-abstract-full').style.display = 'inline'; document.getElementById('2303.11585v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.11585v3-abstract-full" style="display: none;"> Quantum key distribution provides a promising solution for sharing secure keys between two distant parties with unconditional security. Nevertheless, quantum key distribution is still severely threatened by the imperfections of devices. In particular, the classical pulse correlation threatens security when sending decoy states. To address this problem and simplify experimental requirements, we propose a phase-matching quantum key distribution protocol without intensity modulation. Instead of using decoy states, we propose a novel method to estimate the theoretical upper bound on the phase error rate contributed by even-photon-number components. Simulation results show that the transmission distance of our protocol could reach 305 km in telecommunication fiber. Furthermore, we perform a proof-of-principle experiment to demonstrate the feasibility of our protocol, and the key rate reaches 22.5 bps under a 45 dB channel loss. Addressing the security loophole of pulse intensity correlation and replacing continuous random phase with 6 or 8 slices random phase, our protocol provides a promising solution for constructing quantum networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.11585v3-abstract-full').style.display = 'none'; document.getElementById('2303.11585v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Comments are welcome! 12 pages, 6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Applied 20, 024046 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.01132">arXiv:2301.01132</a> <span> [<a href="https://arxiv.org/pdf/2301.01132">pdf</a>, <a href="https://arxiv.org/format/2301.01132">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevApplied.20.044011">10.1103/PhysRevApplied.20.044011 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> One-Time Universal Hashing Quantum Digital Signatures without Perfect Keys </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+B">Bing-Hong Li</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+X">Xiao-Yu Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chen-Long Li</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2301.01132v4-abstract-short" style="display: inline;"> Quantum digital signatures (QDS), generating correlated bit strings among three remote parties for signatures through quantum law, can guarantee non-repudiation, authenticity, and integrity of messages. Recently, one-time universal hashing QDS framework, exploiting the quantum asymmetric encryption and universal hash functions, has been proposed to significantly improve the signature rate and ensu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.01132v4-abstract-full').style.display = 'inline'; document.getElementById('2301.01132v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.01132v4-abstract-full" style="display: none;"> Quantum digital signatures (QDS), generating correlated bit strings among three remote parties for signatures through quantum law, can guarantee non-repudiation, authenticity, and integrity of messages. Recently, one-time universal hashing QDS framework, exploiting the quantum asymmetric encryption and universal hash functions, has been proposed to significantly improve the signature rate and ensure unconditional security by directly signing the hash value of long messages. However, similar to quantum key distribution, this framework utilizes keys with perfect secrecy by performing privacy amplification that introduces cumbersome matrix operations, thereby consuming large computational resources, causing delays and increasing failure probability. Here, we prove that, different from private communication, imperfect quantum keys with limited information leakage can be used for digital signatures and authentication without compromising the security while having eight orders of magnitude improvement on signature rate for signing a megabit message compared with conventional single-bit schemes. This study significantly reduces the delay for data postprocessing and is compatible with any quantum key generation protocols. In our simulation, taking two-photon twin-field key generation protocol as an example, QDS can be practically implemented over a fiber distance of 650 km between the signer and receiver. For the first time, this study offers a cryptographic application of quantum keys with imperfect secrecy and paves a way for the practical and agile implementation of digital signatures in a future quantum network. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.01132v4-abstract-full').style.display = 'none'; document.getElementById('2301.01132v4-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 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">20 pages, 7 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Applied 20, 044011(2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.06148">arXiv:2212.06148</a> <span> [<a href="https://arxiv.org/pdf/2212.06148">pdf</a>, <a href="https://arxiv.org/format/2212.06148">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> </div> <div 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.5.033077">10.1103/PhysRevResearch.5.033077 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Breaking Rate-Distance Limitation of Measurement-Device-Independent Quantum Secret Sharing </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chen-Long Li</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wen-Bo Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+B">Bing-Hong Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+M">Min-Gang Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2212.06148v3-abstract-short" style="display: inline;"> Currently most progresses on quantum secret sharing suffer from rate-distance bound, and thus the key rates are limited. In addition to the limited key rate, the technical difficulty and the corresponding cost together prevent large-scale deployment. Furthermore, the performance of most existing protocols is analyzed in the asymptotic regime without considering participant attacks. Here we report… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.06148v3-abstract-full').style.display = 'inline'; document.getElementById('2212.06148v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.06148v3-abstract-full" style="display: none;"> Currently most progresses on quantum secret sharing suffer from rate-distance bound, and thus the key rates are limited. In addition to the limited key rate, the technical difficulty and the corresponding cost together prevent large-scale deployment. Furthermore, the performance of most existing protocols is analyzed in the asymptotic regime without considering participant attacks. Here we report a measurement-device-independent quantum secret sharing protocol with improved key rate and transmission distance. Based on spatial multiplexing, our protocol shows it can break rate-distance bounds over network under at least ten communication parties. Compared with other protocols, our work improves the secret key rate by more than two orders of magnitude and has a longer transmission distance. We analyze the security of our protocol in the composable framework considering participant attacks and evaluate its performance in the finite-size regime. In addition, we investigate applying our protocol to digital signatures where the signature rate is improved more than $10^7$ times compared with existing protocols. We anticipate that our quantum secret sharing protocol will provide a solid future for multiparty applications on the quantum network. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.06148v3-abstract-full').style.display = 'none'; document.getElementById('2212.06148v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 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">14 pages, 6 figs, arXiv admin note: text overlap with arXiv:2212.05226</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Research 5, 033077 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.05226">arXiv:2212.05226</a> <span> [<a href="https://arxiv.org/pdf/2212.05226">pdf</a>, <a href="https://arxiv.org/format/2212.05226">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s42005-023-01238-5">10.1038/s42005-023-01238-5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Breaking universal limitations on quantum conference key agreement without quantum memory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chen-Long Li</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wen-Bo Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+B">Bing-Hong Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+M">Min-Gang Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2212.05226v2-abstract-short" style="display: inline;"> Quantum conference key agreement is an important cryptographic primitive for future quantum network. Realizing this primitive requires high-brightness and robust multiphoton entanglement sources, which is challenging in experiment and unpractical in application because of limited transmission distance caused by channel loss. Here we report a measurement-device-independent quantum conference key ag… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.05226v2-abstract-full').style.display = 'inline'; document.getElementById('2212.05226v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.05226v2-abstract-full" style="display: none;"> Quantum conference key agreement is an important cryptographic primitive for future quantum network. Realizing this primitive requires high-brightness and robust multiphoton entanglement sources, which is challenging in experiment and unpractical in application because of limited transmission distance caused by channel loss. Here we report a measurement-device-independent quantum conference key agreement protocol with enhanced transmission efficiency over lossy channel. With spatial multiplexing nature and adaptive operation, our protocol can break key rate bounds on quantum communication over quantum network without quantum memory. Compared with previous work, our protocol shows superiority in key rate and transmission distance within the state-of-the-art technology. Furthermore, we analyse the security of our protocol in the composable framework and evaluate its performance in the finite-size regime to show practicality. Based on our results, we anticipate that our protocol will play an indispensable role in constructing multipartite quantum network. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.05226v2-abstract-full').style.display = 'none'; document.getElementById('2212.05226v2-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 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 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">9 pages, 4 figures, 1 table</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Communications Physics 6, 122 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.05224">arXiv:2212.05224</a> <span> [<a href="https://arxiv.org/pdf/2212.05224">pdf</a>, <a href="https://arxiv.org/format/2212.05224">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OL.482287">10.1364/OL.482287 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> All-Photonic Quantum Repeater for Multipartite Entanglement Generation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chen-Long Li</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wen-Bo Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+B">Bing-Hong Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+M">Min-Gang Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2212.05224v1-abstract-short" style="display: inline;"> Quantum network applications like distributed quantum computing and quantum secret sharing present a promising future network equipped with quantum resources. Entanglement generation and distribution over long distances is critical and unavoidable to utilize quantum technology in a fully-connected network. The distribution of bipartite entanglement over long distances has seen some progresses, whi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.05224v1-abstract-full').style.display = 'inline'; document.getElementById('2212.05224v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.05224v1-abstract-full" style="display: none;"> Quantum network applications like distributed quantum computing and quantum secret sharing present a promising future network equipped with quantum resources. Entanglement generation and distribution over long distances is critical and unavoidable to utilize quantum technology in a fully-connected network. The distribution of bipartite entanglement over long distances has seen some progresses, while the distribution of multipartite entanglement over long distances remains unsolved. Here we report a two-dimensional quantum repeater protocol for the generation of multipartite entanglement over long distances with all-photonic framework to fill this gap. The yield of the proposed protocol shows long transmission distance under various numbers of network users. With the improved efficiency and flexibility of extending the number of users, we anticipate that our protocol can work as a significant building block for quantum networks in the future. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.05224v1-abstract-full').style.display = 'none'; document.getElementById('2212.05224v1-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, 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">Journal ref:</span> Opt. Lett. 48, 1244 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.09896">arXiv:2210.09896</a> <span> [<a href="https://arxiv.org/pdf/2210.09896">pdf</a>, <a href="https://arxiv.org/format/2210.09896">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevB.107.165127">10.1103/PhysRevB.107.165127 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Efficient calculation of three-dimensional tensor networks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yang%2C+L">Li-Ping Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y+F">Y. F. Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Z+Y">Z. Y. Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+T">T. Xiang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2210.09896v2-abstract-short" style="display: inline;"> We have proposed an efficient algorithm to calculate physical quantities in the translational invariant three-dimensional tensor networks, which is particularly relevant to the study of the three-dimensional classical statistical models and the (2+1)-dimensional quantum lattice models. In the context of a classical model, we determine the partition function by solving the dominant eigenvalue probl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.09896v2-abstract-full').style.display = 'inline'; document.getElementById('2210.09896v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.09896v2-abstract-full" style="display: none;"> We have proposed an efficient algorithm to calculate physical quantities in the translational invariant three-dimensional tensor networks, which is particularly relevant to the study of the three-dimensional classical statistical models and the (2+1)-dimensional quantum lattice models. In the context of a classical model, we determine the partition function by solving the dominant eigenvalue problem of the transfer matrix, whose left and right dominant eigenvectors are represented by two projected entangled simplex states. These two projected entangled simplex states are not Hermitian conjugate to each other but are appropriately arranged so that their inner product can be computed much more efficiently than in the usual prescription. For the three-dimensional Ising model, the calculated internal energy and spontaneous magnetization agree with the published results in the literature. The possible improvement and extension to other models are also discussed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.09896v2-abstract-full').style.display = 'none'; document.getElementById('2210.09896v2-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 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> <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, 10 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 107, 165127 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.05618">arXiv:2208.05618</a> <span> [<a href="https://arxiv.org/pdf/2208.05618">pdf</a>, <a href="https://arxiv.org/format/2208.05618">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.129.100501">10.1103/PhysRevLett.129.100501 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental investigation of quantum correlations in a two-qutrit spin system </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yue Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wenquan Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Ye%2C+X">Xiangyu Ye</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Ya Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chengjie Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Duan%2C+C">Chang-Kui Duan</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+X">Xing Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+J">Jiangfeng Du</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.05618v1-abstract-short" style="display: inline;"> We report an experimental investigation of quantum correlations in a two-qutrit spin system in a single nitrogen-vacancy center in diamond at room temperatures. Quantum entanglement between two qutrits was observed at room temperature and the existence of non-classical correlations beyond entanglement in the qutrit case has been revealed. Our work demonstrates the potential of the NV centers as th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.05618v1-abstract-full').style.display = 'inline'; document.getElementById('2208.05618v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.05618v1-abstract-full" style="display: none;"> We report an experimental investigation of quantum correlations in a two-qutrit spin system in a single nitrogen-vacancy center in diamond at room temperatures. Quantum entanglement between two qutrits was observed at room temperature and the existence of non-classical correlations beyond entanglement in the qutrit case has been revealed. Our work demonstrates the potential of the NV centers as the multi-qutrit system to execute quantum information tasks and provides a powerful experimental platform for studying fundamental physics of high-dimensional quantum systems in future. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.05618v1-abstract-full').style.display = 'none'; document.getElementById('2208.05618v1-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 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.00296">arXiv:2207.00296</a> <span> [<a href="https://arxiv.org/pdf/2207.00296">pdf</a>, <a href="https://arxiv.org/format/2207.00296">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"> Sharing tripartite nonlocality sequentially by arbitrarily many independent observers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y+X+M+L+L">Ya Xi Mao-Sheng Li Libin Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+Z">Zhu-Jun Zheng</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.00296v2-abstract-short" style="display: inline;"> There exist bipartite entangled states whose violations of Clauser-Horne-Shimony-Holt (CHSH) Bell inequality can be observed by a single Alice and arbitrarily many sequential Bobs [Phys. Rev. Lett. 125, 090401 (2020)]. Here we consider its analogues for tripartite systems: a tripartite entangled state is shared among Alice, Bob and multiple Charlies. The first Charlie measures his qubit and then p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.00296v2-abstract-full').style.display = 'inline'; document.getElementById('2207.00296v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.00296v2-abstract-full" style="display: none;"> There exist bipartite entangled states whose violations of Clauser-Horne-Shimony-Holt (CHSH) Bell inequality can be observed by a single Alice and arbitrarily many sequential Bobs [Phys. Rev. Lett. 125, 090401 (2020)]. Here we consider its analogues for tripartite systems: a tripartite entangled state is shared among Alice, Bob and multiple Charlies. The first Charlie measures his qubit and then passes his qubit to the next Charlie who measures again with other measurements and so on. The goal is to maximize the number of Charlies that can observe some kind of nonlocality with the single Alice and Bob. It has been shown that at most two Charlies could share genuine nonlocality of the Greenberger-Horne-Zeilinger (GHZ) state via the violation of Svetlichny inequality with Alice and Bob [Quantum Inf. Process. 18, 42 (2019) and Phys. Rev. A 103, 032216 (2021)]. In this work, we show that arbitrarily many Charlies can have standard nonlocality (via violations of Mermin inequality) and some other kind of genuine nonlocality (which is known as genuinely nonsignal nonlocality) with the single Alice and single Bob. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.00296v2-abstract-full').style.display = 'none'; document.getElementById('2207.00296v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 2figure</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Physical Review A 107, 062419 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.12156">arXiv:2204.12156</a> <span> [<a href="https://arxiv.org/pdf/2204.12156">pdf</a>, <a href="https://arxiv.org/ps/2204.12156">ps</a>, <a href="https://arxiv.org/format/2204.12156">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> </div> <div 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.481832">10.1364/OE.481832 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Source-independent quantum random number generator against tailored detector blinding attacks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wen-Bo Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Y">Yu-Shuo Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+S">Si-Cheng Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+Z">Ze-Jie Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+K">Kun Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2204.12156v2-abstract-short" style="display: inline;"> Randomness, mainly in the form of random numbers, is the fundamental prerequisite for the security of many cryptographic tasks. Quantum randomness can be extracted even if adversaries are fully aware of the protocol and even control the randomness source. However, an adversary can further manipulate the randomness via tailored detector blinding attacks, which are hacking attacks suffered by protoc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.12156v2-abstract-full').style.display = 'inline'; document.getElementById('2204.12156v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.12156v2-abstract-full" style="display: none;"> Randomness, mainly in the form of random numbers, is the fundamental prerequisite for the security of many cryptographic tasks. Quantum randomness can be extracted even if adversaries are fully aware of the protocol and even control the randomness source. However, an adversary can further manipulate the randomness via tailored detector blinding attacks, which are hacking attacks suffered by protocols with trusted detectors. Here, by treating no-click events as valid events, we propose a quantum random number generation protocol that can simultaneously address source vulnerability and ferocious tailored detector blinding attacks. The method can be extended to high-dimensional random number generation. We experimentally demonstrate the ability of our protocol to generate random numbers for two-dimensional measurement with a generation speed of 0.1 bit per pulse. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.12156v2-abstract-full').style.display = 'none'; document.getElementById('2204.12156v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 6 figures, 6 tables, comments are welcome</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Opt. Express 31, 11292 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.08323">arXiv:2204.08323</a> <span> [<a href="https://arxiv.org/pdf/2204.08323">pdf</a>, <a href="https://arxiv.org/ps/2204.08323">ps</a>, <a href="https://arxiv.org/format/2204.08323">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> </div> <div 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.2022.10.010">10.1016/j.scib.2022.10.010 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental measurement-device-independent type quantum key distribution with flawed and correlated sources </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Gu%2C+J">Jie Gu</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+X">Xiao-Yu Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=He%2C+Z">Zong-Wu He</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+Z">Ze-Jie Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2204.08323v3-abstract-short" style="display: inline;"> The security of quantum key distribution (QKD) is severely threatened by discrepancies between realistic devices and theoretical assumptions. Recently, a significant framework called the reference technique was proposed to provide security against arbitrary source flaws under current technology such as state preparation flaws, side channels caused by mode dependencies, the Trojan horse atttacks an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.08323v3-abstract-full').style.display = 'inline'; document.getElementById('2204.08323v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.08323v3-abstract-full" style="display: none;"> The security of quantum key distribution (QKD) is severely threatened by discrepancies between realistic devices and theoretical assumptions. Recently, a significant framework called the reference technique was proposed to provide security against arbitrary source flaws under current technology such as state preparation flaws, side channels caused by mode dependencies, the Trojan horse atttacks and pulse correlations. Here, we adopt the reference technique to prove security of an efficient four-phase measurement-device-independent QKD using laser pulses against potential source imperfections. We present a characterization of source flaws and connect them to experiments, together with a finite-key analysis against coherent attacks. In addition, we demonstrate the feasibility of our protocol through a proof-of-principle experimental implementation and achieve a secure key rate of 253 bps with a 20 dB channel loss. Compared with previous QKD protocols with imperfect devices, our study considerably improves both the secure key rate and the transmission distance, and shows application potential in the practical deployment of secure QKD with device imperfections. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.08323v3-abstract-full').style.display = 'none'; document.getElementById('2204.08323v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 7 figures, 6 tables. Comments are welcome!</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Science Bulletin 67, 2167-2175 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.11635">arXiv:2112.11635</a> <span> [<a href="https://arxiv.org/pdf/2112.11635">pdf</a>, <a href="https://arxiv.org/format/2112.11635">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PRXQuantum.3.020315">10.1103/PRXQuantum.3.020315 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Breaking the Rate-Loss Bound of Quantum Key Distribution with Asynchronous Two-Photon Interference </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Y">Yu-Shuo Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Weng%2C+C">Chen-Xun Weng</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+X">Xiao-Yu Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Jia%2C+Z">Zhao-Ying Jia</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Y">Yu Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yang Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2112.11635v3-abstract-short" style="display: inline;"> Twin-field quantum key distribution can overcome the secret key capacity of repeaterless quantum key distribution via single-photon interference. However, to compensate for the channel fluctuations and lock the laser fluctuations, the techniques of phase tracking and phase locking are indispensable in experiment, which drastically increase experimental complexity and hinder free-space realization.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.11635v3-abstract-full').style.display = 'inline'; document.getElementById('2112.11635v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.11635v3-abstract-full" style="display: none;"> Twin-field quantum key distribution can overcome the secret key capacity of repeaterless quantum key distribution via single-photon interference. However, to compensate for the channel fluctuations and lock the laser fluctuations, the techniques of phase tracking and phase locking are indispensable in experiment, which drastically increase experimental complexity and hinder free-space realization. Inspired by the duality in entanglement, we herein present an asynchronous measurement-device-independent quantum key distribution protocol that can surpass the secret key capacity even without phase tracking and phase locking. Leveraging the concept of time multiplexing, asynchronous two-photon Bell-state measurement is realized by postmatching two interference detection events. For a 1 GHz system, the new protocol reaches a transmission distance of 450 km without phase tracking. After further removing phase locking, our protocol is still capable of breaking the capacity at 270 km. Intriguingly, when using the same experimental techniques, our protocol has a higher key rate than the phase-matching-type twin-field protocol. In the presence of imperfect intensity modulation, it also has a significant advantage in terms of the transmission distance over the sending-or-not-sending type twin-field protocol. With high key rates and accessible technology, our work provides a promising candidate for practical scalable quantum communication networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.11635v3-abstract-full').style.display = 'none'; document.getElementById('2112.11635v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 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">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 10 figures. arXiv admin note: text overlap with arXiv:2112.11165</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> PRX Quantum 3, 020315 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.11165">arXiv:2112.11165</a> <span> [<a href="https://arxiv.org/pdf/2112.11165">pdf</a>, <a href="https://arxiv.org/format/2112.11165">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Cryptography and Security">cs.CR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Networking and Internet Architecture">cs.NI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.107.042603">10.1103/PhysRevA.107.042603 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Scalable High-Rate Twin-Field Quantum Key Distribution Networks without Constraint of Probability and Intensity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Weng%2C+C">Chen-Xun Weng</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Y">Yu-Shuo Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yang Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2112.11165v3-abstract-short" style="display: inline;"> Implementation of a twin-field quantum key distribution network faces limitations, including the low tolerance of interference errors for phase-matching type protocols and the strict constraint regarding intensity and probability for sending-or-not-sending type protocols. Here, we propose a two-photon twin-field quantum key distribution protocol and achieve twin-field-type two-photon interference… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.11165v3-abstract-full').style.display = 'inline'; document.getElementById('2112.11165v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.11165v3-abstract-full" style="display: none;"> Implementation of a twin-field quantum key distribution network faces limitations, including the low tolerance of interference errors for phase-matching type protocols and the strict constraint regarding intensity and probability for sending-or-not-sending type protocols. Here, we propose a two-photon twin-field quantum key distribution protocol and achieve twin-field-type two-photon interference through post-matching phase-correlated single-photon interference events. We exploit the non-interference mode as the code mode to highly tolerate interference errors, and the two-photon interference naturally removes the intensity and probability constraint. Therefore, our protocol can transcend the abovementioned limitations while breaking the secret key capacity of repeaterless quantum key distribution. Simulations show that for a four-user networks, under which each node with fixed system parameters can dynamically switch different attenuation links, the key rates of our protocol for all six links can either exceed or approach the secret key capacity. However, the key rates of all links are lower than the key capacity when using phase-matching type protocols. Additionally, four of the links could not extract the key when using sending-or-not-sending type protocols. We anticipate that our protocol can facilitate the development of practical and efficient quantum networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.11165v3-abstract-full').style.display = 'none'; document.getElementById('2112.11165v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 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">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 6 figures, 3 tables, Accepted for Publication in Phys. Rev. A</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A 107, 042603 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.07884">arXiv:2112.07884</a> <span> [<a href="https://arxiv.org/pdf/2112.07884">pdf</a>, <a href="https://arxiv.org/format/2112.07884">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="Computational Complexity">cs.CC</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</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/10.34133/2022/9798679">10.34133/2022/9798679 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental quantum advantage with quantum coupon collector </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+M">Min-Gang Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+X">Xiao-Yu Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Y">Yu-Shuo Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yang Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Bao%2C+Y">Yu Bao</a>, <a href="/search/quant-ph?searchtype=author&query=Jia%2C+Z">Zhao-Ying Jia</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2112.07884v2-abstract-short" style="display: inline;"> An increasing number of communication and computational schemes with quantum advantages have recently been proposed, which implies that quantum technology has fertile application prospects. However, demonstrating these schemes experimentally continues to be a central challenge because of the difficulty in preparing high-dimensional states or highly entangled states. In this study, we introduce and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.07884v2-abstract-full').style.display = 'inline'; document.getElementById('2112.07884v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.07884v2-abstract-full" style="display: none;"> An increasing number of communication and computational schemes with quantum advantages have recently been proposed, which implies that quantum technology has fertile application prospects. However, demonstrating these schemes experimentally continues to be a central challenge because of the difficulty in preparing high-dimensional states or highly entangled states. In this study, we introduce and analyse a quantum coupon collector protocol by employing coherent states and simple linear optical elements, which was successfully demonstrated using realistic experimental equipment. We showed that our protocol can significantly reduce the number of samples needed to learn a specific set compared with the classical limit of the coupon collector problem. We also discuss the potential values and expansions of the quantum coupon collector by constructing a quantum blind box game. The information transmitted by the proposed game also broke the classical limit. These results strongly prove the advantages of quantum mechanics in machine learning and communication complexity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.07884v2-abstract-full').style.display = 'none'; document.getElementById('2112.07884v2-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 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 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">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 3 figures, 3 tables, Accepted by Research</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Research 2022, 9798679 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.13717">arXiv:2109.13717</a> <span> [<a href="https://arxiv.org/pdf/2109.13717">pdf</a>, <a href="https://arxiv.org/format/2109.13717">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Other Condensed Matter">cond-mat.other</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.127.147401">10.1103/PhysRevLett.127.147401 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimentally Detecting Quantized Zak Phases without Chiral Symmetry in Photonic Lattices </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Jiao%2C+Z">Zhi-Qiang Jiao</a>, <a href="/search/quant-ph?searchtype=author&query=Longhi%2C+S">Stefano Longhi</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xiao-Wei Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+J">Jun Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+W">Wen-Hao Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yao Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yu-Xuan Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+L">Li Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+R">Ruo-Jing Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Qiao%2C+L">Lu-Feng Qiao</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+X">Xian-Min Jin</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="2109.13717v1-abstract-short" style="display: inline;"> Symmetries play a major role in identifying topological phases of matter and in establishing a direct connection between protected edge states and topological bulk invariants via the bulk-boundary correspondence. One-dimensional lattices are deemed to be protected by chiral symmetry, exhibiting quantized Zak phases and protected edge states, but not for all cases. Here, we experimentally realize a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.13717v1-abstract-full').style.display = 'inline'; document.getElementById('2109.13717v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.13717v1-abstract-full" style="display: none;"> Symmetries play a major role in identifying topological phases of matter and in establishing a direct connection between protected edge states and topological bulk invariants via the bulk-boundary correspondence. One-dimensional lattices are deemed to be protected by chiral symmetry, exhibiting quantized Zak phases and protected edge states, but not for all cases. Here, we experimentally realize an extended Su-Schrieffer-Heeger model with broken chiral symmetry by engineering one-dimensional zigzag photonic lattices, where the long-range hopping breaks chiral symmetry but ensures the existence of inversion symmetry. By the averaged mean displacement method, we detect topological invariants directly in the bulk through the continuous-time quantum walk of photons. Our results demonstrate that inversion symmetry protects the quantized Zak phase, but edge states can disappear in the topological nontrivial phase, thus breaking the conventional bulk-boundary correspondence. Our photonic lattice provides a useful platform to study the interplay among topological phases, symmetries, and the bulk-boundary correspondence. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.13717v1-abstract-full').style.display = 'none'; document.getElementById('2109.13717v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 September, 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, 4 figures, 53 references, 1 supplemental materials</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, 147401 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.02578">arXiv:2108.02578</a> <span> [<a href="https://arxiv.org/pdf/2108.02578">pdf</a>, <a href="https://arxiv.org/format/2108.02578">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/s41598-022-12647-x">10.1038/s41598-022-12647-x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Neural network-based prediction of the secret-key rate of quantum key distribution </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+M">Min-Gang Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zhi-Ping Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wen-Bo Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chen-Long Li</a>, <a href="/search/quant-ph?searchtype=author&query=Bai%2C+J">Jun-Lin Bai</a>, <a href="/search/quant-ph?searchtype=author&query=Xue%2C+Y">Yi-Ran Xue</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2108.02578v3-abstract-short" style="display: inline;"> Numerical methods are widely used to calculate the secure key rate of many quantum key distribution protocols in practice, but they consume many computing resources and are too time-consuming. In this work, we take the homodyne detection discrete-modulated continuous-variable quantum key distribution (CV-QKD) as an example, and construct a neural network that can quickly predict the secure key rat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.02578v3-abstract-full').style.display = 'inline'; document.getElementById('2108.02578v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.02578v3-abstract-full" style="display: none;"> Numerical methods are widely used to calculate the secure key rate of many quantum key distribution protocols in practice, but they consume many computing resources and are too time-consuming. In this work, we take the homodyne detection discrete-modulated continuous-variable quantum key distribution (CV-QKD) as an example, and construct a neural network that can quickly predict the secure key rate based on the experimental parameters and experimental results. Compared to traditional numerical methods, the speed of the neural network is improved by several orders of magnitude. Importantly, the predicted key rates are not only highly accurate but also highly likely to be secure. This allows the secure key rate of discrete-modulated CV-QKD to be extracted in real time on a low-power platform. Furthermore, our method is versatile and can be extended to quickly calculate the complex secure key rates of various other unstructured quantum key distribution protocols. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.02578v3-abstract-full').style.display = 'none'; document.getElementById('2108.02578v3-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 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 5 figures, 2 tables</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Sci. Rep. 12, 8879 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.14089">arXiv:2107.14089</a> <span> [<a href="https://arxiv.org/pdf/2107.14089">pdf</a>, <a href="https://arxiv.org/ps/2107.14089">ps</a>, <a href="https://arxiv.org/format/2107.14089">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/10.1093/nsr/nwac228">10.1093/nsr/nwac228 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental quantum secure network with digital signatures and encryption </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+C">Chen-Long Li</a>, <a href="/search/quant-ph?searchtype=author&query=Weng%2C+C">Chen-Xun Weng</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+B">Bing-Hong Li</a>, <a href="/search/quant-ph?searchtype=author&query=Gu%2C+J">Jie Gu</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+Y">Yu-Shuo Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+S">Shan Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2107.14089v4-abstract-short" style="display: inline;"> Cryptography promises four information security objectives, namely, confidentiality, integrity, authenticity, and non-repudiation, to support trillions of transactions annually in the digital economy. Efficient digital signatures, ensuring the integrity, authenticity, and non-repudiation of data with information-theoretical security are highly urgent and intractable open problems in cryptography.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.14089v4-abstract-full').style.display = 'inline'; document.getElementById('2107.14089v4-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.14089v4-abstract-full" style="display: none;"> Cryptography promises four information security objectives, namely, confidentiality, integrity, authenticity, and non-repudiation, to support trillions of transactions annually in the digital economy. Efficient digital signatures, ensuring the integrity, authenticity, and non-repudiation of data with information-theoretical security are highly urgent and intractable open problems in cryptography. Here, we propose a protocol of high-efficiency quantum digital signatures using secret sharing, one-time universal$_2$ hashing, and the one-time pad. We just need to use a 384-bit key to sign documents of up to $2^{64}$ lengths with a security bound of $10^{-19}$. If one-megabit document is signed, the signature efficiency is improved by more than $10^8$ times compared with previous quantum digital signature protocols. Furthermore, we build the first all-in-one quantum secure network integrating information-theoretically secure communication, digital signatures, secret sharing, and conference key agreement and experimentally demonstrate this signature efficiency advantage. Our work completes the cryptography toolbox of the four information security objectives. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.14089v4-abstract-full').style.display = 'none'; document.getElementById('2107.14089v4-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 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 29 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">19 pages, 7 figures, 4 tables. Quantum digital signatures and quantum private communication maintain a consistent level of practicality</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Natl. Sci. Rev. 10, nwac228 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.10321">arXiv:2104.10321</a> <span> [<a href="https://arxiv.org/pdf/2104.10321">pdf</a>, <a href="https://arxiv.org/ps/2104.10321">ps</a>, <a href="https://arxiv.org/format/2104.10321">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.440365">10.1364/OE.440365 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Secure Quantum Secret Sharing without Signal Disturbance Monitoring </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Gu%2C+J">Jie Gu</a>, <a href="/search/quant-ph?searchtype=author&query=Xie%2C+Y">Yuan-Mei Xie</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W">Wen-Bo Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="2104.10321v2-abstract-short" style="display: inline;"> Quantum secret sharing (QSS) is an essential primitive for the future quantum internet, which promises secure multiparty communication. However, developing a large-scale QSS network is a huge challenge due to the channel loss and the requirement of multiphoton interference or high-fidelity multipartite entanglement distribution. Here, we propose a three-user QSS protocol without monitoring signal… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.10321v2-abstract-full').style.display = 'inline'; document.getElementById('2104.10321v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.10321v2-abstract-full" style="display: none;"> Quantum secret sharing (QSS) is an essential primitive for the future quantum internet, which promises secure multiparty communication. However, developing a large-scale QSS network is a huge challenge due to the channel loss and the requirement of multiphoton interference or high-fidelity multipartite entanglement distribution. Here, we propose a three-user QSS protocol without monitoring signal disturbance, which is capable of ensuring the unconditional security. The final key rate of our protocol can be demonstrated to break the Pirandola-Laurenza-Ottaviani-Banchi bound of quantum channel and its simulated transmission distance can approach over 600 km using current techniques. Our results pave the way to realizing high-rate and large-scale QSS networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.10321v2-abstract-full').style.display = 'none'; document.getElementById('2104.10321v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">8 pages, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Opt. Express 29, 32244 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.03967">arXiv:2012.03967</a> <span> [<a href="https://arxiv.org/pdf/2012.03967">pdf</a>, <a href="https://arxiv.org/format/2012.03967">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Quantum Advantage with Timestamp Membosonsampling </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Gao%2C+J">Jun Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xiao-Wei Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+W">Wen-Hao Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Jiao%2C+Z">Zhi-Qiang Jiao</a>, <a href="/search/quant-ph?searchtype=author&query=Ren%2C+R">Ruo-Jing Ren</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yu-Xuan Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Qiao%2C+L">Lu-Feng Qiao</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+X">Xiao-Yun Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chao-Ni Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Pang%2C+X">Xiao-Ling Pang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yao Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+X">Xian-Min Jin</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="2012.03967v1-abstract-short" style="display: inline;"> Quantum computer, harnessing quantum superposition to boost a parallel computational power, promises to outperform its classical counterparts and offer an exponentially increased scaling. The term "quantum advantage" was proposed to mark the key point when people can solve a classically intractable problem by artificially controlling a quantum system in an unprecedented scale, even without error c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.03967v1-abstract-full').style.display = 'inline'; document.getElementById('2012.03967v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.03967v1-abstract-full" style="display: none;"> Quantum computer, harnessing quantum superposition to boost a parallel computational power, promises to outperform its classical counterparts and offer an exponentially increased scaling. The term "quantum advantage" was proposed to mark the key point when people can solve a classically intractable problem by artificially controlling a quantum system in an unprecedented scale, even without error correction or known practical applications. Boson sampling, a problem about quantum evolutions of multi-photons on multimode photonic networks, as well as its variants, has been considered as a promising candidate to reach this milestone. However, the current photonic platforms suffer from the scaling problems, both in photon numbers and circuit modes. Here, we propose a new variant of the problem, timestamp membosonsampling, exploiting the timestamp information of single photons as free resources, and the scaling of the problem can be in principle extended to infinitely large. We experimentally verify the scheme on a self-looped photonic chip inspired by memristor, and obtain multi-photon registrations up to 56-fold in 750,000 modes with a Hilbert space up to $10^{254}$. Our work exhibits an integrated and cost-efficient shortcut stepping into the "quantum advantage" regime in a photonic system far beyond previous scenarios, and provide a scalable and controllable platform for quantum information processing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.03967v1-abstract-full').style.display = 'none'; document.getElementById('2012.03967v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 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">30 pages, 10 figures, under review (submitted 16th Oct). We demonstrate quantum advantage in an integrated and cost-efficient fashion</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2010.10230">arXiv:2010.10230</a> <span> [<a href="https://arxiv.org/pdf/2010.10230">pdf</a>, <a href="https://arxiv.org/format/2010.10230">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/PhysRevApplied.18.L051001">10.1103/PhysRevApplied.18.L051001 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Time-Delayed Magnetic Control and Narrowing of X-Ray frequency Spectra in Two-Target Nuclear Forward Scattering </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Lin%2C+P">Po-Han Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yen-Yu Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Liao%2C+W">Wen-Te Liao</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="2010.10230v2-abstract-short" style="display: inline;"> Controlling and narrowing x-ray frequency spectra in magnetically perturbed two-target nuclear forward scattering is theoretically studied. We show that different hard-x-ray spectral redistributions can be achieved by single or multiple switching of magnetic field in nuclear targets. Our scheme can generate x-ray spectral lines with tenfold intensity enhancement and spectral width narrower than fo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.10230v2-abstract-full').style.display = 'inline'; document.getElementById('2010.10230v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.10230v2-abstract-full" style="display: none;"> Controlling and narrowing x-ray frequency spectra in magnetically perturbed two-target nuclear forward scattering is theoretically studied. We show that different hard-x-ray spectral redistributions can be achieved by single or multiple switching of magnetic field in nuclear targets. Our scheme can generate x-ray spectral lines with tenfold intensity enhancement and spectral width narrower than four times the nuclear natural linewidth. The present results pave the way towards a brighter and flexible x-ray source for precision spectroscopy of nuclear resonances using modern synchrotron radiation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.10230v2-abstract-full').style.display = 'none'; document.getElementById('2010.10230v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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">5 pages, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Applied 18, L051001 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2010.09620">arXiv:2010.09620</a> <span> [<a href="https://arxiv.org/pdf/2010.09620">pdf</a>, <a href="https://arxiv.org/ps/2010.09620">ps</a>, <a href="https://arxiv.org/format/2010.09620">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="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.104.015215">10.1103/PhysRevE.104.015215 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Spontaneous and explicit parity-time-symmetry breaking in drift wave instabilities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Qin%2C+H">Hong Qin</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yichen Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Glasser%2C+A+S">Alexander S. Glasser</a>, <a href="/search/quant-ph?searchtype=author&query=Yahalom%2C+A">Asher Yahalom</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="2010.09620v1-abstract-short" style="display: inline;"> A method of Parity-Time (PT)-symmetry analysis is introduced to study the high dimensional, complicated parameter space of drift wave instabilities. We show that spontaneous PT-symmetry breaking leads to the Ion Temperature Gradient (ITG) instability of drift waves, and the collisional instability is the result of explicit PT-symmetry breaking. A new unstable drift wave induced by finite collision… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.09620v1-abstract-full').style.display = 'inline'; document.getElementById('2010.09620v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.09620v1-abstract-full" style="display: none;"> A method of Parity-Time (PT)-symmetry analysis is introduced to study the high dimensional, complicated parameter space of drift wave instabilities. We show that spontaneous PT-symmetry breaking leads to the Ion Temperature Gradient (ITG) instability of drift waves, and the collisional instability is the result of explicit PT-symmetry breaking. A new unstable drift wave induced by finite collisionality is identified. It is also found that gradients of ion temperature and density can destabilize the ion cyclotron waves when PT symmetry is explicitly broken by a finite collisionality. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.09620v1-abstract-full').style.display = 'none'; document.getElementById('2010.09620v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. E 104, 015215 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1805.12007">arXiv:1805.12007</a> <span> [<a href="https://arxiv.org/pdf/1805.12007">pdf</a>, <a href="https://arxiv.org/ps/1805.12007">ps</a>, <a href="https://arxiv.org/format/1805.12007">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/s41598-018-36366-4">10.1038/s41598-018-36366-4 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Phase self-aligned continuous-variable measurement-device-independent quantum key distribution </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+W">Wei Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1805.12007v2-abstract-short" style="display: inline;"> Continuous-variable measurement-independent-device quantum key distribution (CV-MDI-QKD) can offer high secure key rate at metropolitan distance and remove all side channel loopholes of detection as well. However, there is no complete experimental demonstration of CV-MDI-QKD due to the remote distance phase-locking techniques challenge. Here, we present a new optical scheme to overcome this diffic… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.12007v2-abstract-full').style.display = 'inline'; document.getElementById('1805.12007v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1805.12007v2-abstract-full" style="display: none;"> Continuous-variable measurement-independent-device quantum key distribution (CV-MDI-QKD) can offer high secure key rate at metropolitan distance and remove all side channel loopholes of detection as well. However, there is no complete experimental demonstration of CV-MDI-QKD due to the remote distance phase-locking techniques challenge. Here, we present a new optical scheme to overcome this difficulty and also removes the requirement of two identical independent lasers. We anticipate that our new scheme can be used to demonstrate the in-field CV-MDI-QKD experiment and build the CV-MDI-QKD network with untrusted source. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.12007v2-abstract-full').style.display = 'none'; document.getElementById('1805.12007v2-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 January, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 May, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">26 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Scientific Reports 9, 49 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1805.12004">arXiv:1805.12004</a> <span> [<a href="https://arxiv.org/pdf/1805.12004">pdf</a>, <a href="https://arxiv.org/ps/1805.12004">ps</a>, <a href="https://arxiv.org/format/1805.12004">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/s41598-019-39454-1">10.1038/s41598-019-39454-1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Measurement-Device-Independent Twin-Field Quantum Key Distribution </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1805.12004v3-abstract-short" style="display: inline;"> The ultimate aim of quantum key distribution (QKD) is improving the performance of transmission distance and key generation speed. Unfortunately, it is believed to be limited by the secret-key capacity of quantum channel without quantum repeater. Recently, a novel twin-field QKD (TFQKD) [Nature 557, 400 (2018)] is proposed to break through the limit, where the key rate is proportional to the squar… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.12004v3-abstract-full').style.display = 'inline'; document.getElementById('1805.12004v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1805.12004v3-abstract-full" style="display: none;"> The ultimate aim of quantum key distribution (QKD) is improving the performance of transmission distance and key generation speed. Unfortunately, it is believed to be limited by the secret-key capacity of quantum channel without quantum repeater. Recently, a novel twin-field QKD (TFQKD) [Nature 557, 400 (2018)] is proposed to break through the limit, where the key rate is proportional to the square-root of channel transmittance. Here, by using the vacuum and one-photon state as a qubit, we show that the TF-QKD can be regarded as a measurement-device-independent QKD (MDI-QKD) with single-photon Bell state measurement. Therefore, the MDI property of TF-QKD can be understood clearly. Importantly, the universal security proof theories can be directly used for the TF-QKD, such as BB84, six-state and reference-frame-independent schemes. Furthermore, we propose a feasible experimental scheme for the proof-of-principle experimental demonstration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.12004v3-abstract-full').style.display = 'none'; document.getElementById('1805.12004v3-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 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 May, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">29 pages, 4 figures, The security of TF-QKD with single-photon Bell state measurement</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Scientific Reports 9, 3045 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1706.09259">arXiv:1706.09259</a> <span> [<a href="https://arxiv.org/pdf/1706.09259">pdf</a>, <a href="https://arxiv.org/format/1706.09259">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> </div> </div> <p class="title is-5 mathjax"> Experimental protection of the coherence of a molecular qubit exceeding a millisecond </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Dai%2C+Y">Yingqiu Dai</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+Z">Zhifu Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yue Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Qin%2C+X">Xi Qin</a>, <a href="/search/quant-ph?searchtype=author&query=Mu%2C+S">Shiwei Mu</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Yang Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Su%2C+J">Ji-Hu Su</a>, <a href="/search/quant-ph?searchtype=author&query=Qin%2C+L">Lei Qin</a>, <a href="/search/quant-ph?searchtype=author&query=Zhai%2C+Y">Yuan-Qi Zhai</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+Y">Yi-Fei Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Rong%2C+X">Xing Rong</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+J">Jiangfeng Du</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1706.09259v1-abstract-short" style="display: inline;"> There are several important solid-state systems, such as defects in solids, superconducting circuits and molecular qubits, for attractive candidates of quantum computations. Molecular qubits, which benefit from the power of chemistry for the tailored and inexpensive synthesis of new systems, face the challenge from decoherence effect. The decoherence effect is due to the molecular qubits' inevitab… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1706.09259v1-abstract-full').style.display = 'inline'; document.getElementById('1706.09259v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1706.09259v1-abstract-full" style="display: none;"> There are several important solid-state systems, such as defects in solids, superconducting circuits and molecular qubits, for attractive candidates of quantum computations. Molecular qubits, which benefit from the power of chemistry for the tailored and inexpensive synthesis of new systems, face the challenge from decoherence effect. The decoherence effect is due to the molecular qubits' inevitable interactions to their environment. Strategies to overcome decoherence effect have been developed, such as designing a nuclear spin free environment and working at atomic clock transitions. These chemical approaches, however, have some fundamental limitations. For example, chemical approach restricts the ligand selection and design to ligands with zero nuclear magnetic dipole moment, such as carbon, oxygen, and sulfur. Herein, a physical approach, named Dynamical decoupling (DD), is utilized to combat decoherence, while the limitations of the chemical approaches can be avoided. The phase memory time $T_2$ for a transition metal complex has been prolonged to exceed one millisecond ($1.4~$ms) by employing DD. The single qubit figure of merit $Q_M $ reaches $ 1.4\times 10^5$, which is $40$ times better than that previously reported value for such system. Our results show that molecular qubits, with milliseconds $T_2$, are promising candidates for quantum information processing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1706.09259v1-abstract-full').style.display = 'none'; document.getElementById('1706.09259v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 June, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2017. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1608.01086">arXiv:1608.01086</a> <span> [<a href="https://arxiv.org/pdf/1608.01086">pdf</a>, <a href="https://arxiv.org/ps/1608.01086">ps</a>, <a href="https://arxiv.org/format/1608.01086">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.95.032334">10.1103/PhysRevA.95.032334 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental Quantum Digital Signature over 102 km </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+H">Hui Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Tang%2C+Q">Qi-Jie Tang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jian Wang</a>, <a href="/search/quant-ph?searchtype=author&query=You%2C+L">Li-Xing You</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+W">Wei-Jun Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+S">Si-Jing Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Zhen Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Q">Qiang Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+T">Teng-Yun Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing Chen</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="1608.01086v1-abstract-short" style="display: inline;"> Quantum digital signature (QDS) is an approach to guarantee the nonrepudiation, unforgeability and transferability of a signature with the information-theoretical security. All previous experimental realizations of QDS relied on an unrealistic assumption of secure channels and the longest distance is only several kilometers. Here, we have experimentally demonstrated a recently proposed QDS protoco… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.01086v1-abstract-full').style.display = 'inline'; document.getElementById('1608.01086v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1608.01086v1-abstract-full" style="display: none;"> Quantum digital signature (QDS) is an approach to guarantee the nonrepudiation, unforgeability and transferability of a signature with the information-theoretical security. All previous experimental realizations of QDS relied on an unrealistic assumption of secure channels and the longest distance is only several kilometers. Here, we have experimentally demonstrated a recently proposed QDS protocol without any secure channel. Exploiting the decoy state modulation, we have successfully signed one bit message through up to 102 km optical fiber. Furthermore, we continuously run the system to sign the longer message "USTC" with 32 bit at the distance of 51 km. Our results pave the way towards the practical application of QDS. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.01086v1-abstract-full').style.display = 'none'; document.getElementById('1608.01086v1-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 August, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5+5 page, 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 95, 032334 (2017) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1607.02366">arXiv:1607.02366</a> <span> [<a href="https://arxiv.org/pdf/1607.02366">pdf</a>, <a href="https://arxiv.org/ps/1607.02366">ps</a>, <a href="https://arxiv.org/format/1607.02366">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/srep29482">10.1038/srep29482 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Security of quantum key distribution with multiphoton components </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Mao%2C+Y">Yingqiu Mao</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="1607.02366v1-abstract-short" style="display: inline;"> Most qubit-based quantum key distribution (QKD) protocols extract the secure key merely from single-photon component of the attenuated lasers. However, with the Scarani-Acin-Ribordy-Gisin 2004 (SARG04) QKD protocol, the unconditionally secure key can be extracted from the two-photon component by modifying the classical post-processing procedure in the BB84 protocol. Employing the merits of SARG04… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1607.02366v1-abstract-full').style.display = 'inline'; document.getElementById('1607.02366v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1607.02366v1-abstract-full" style="display: none;"> Most qubit-based quantum key distribution (QKD) protocols extract the secure key merely from single-photon component of the attenuated lasers. However, with the Scarani-Acin-Ribordy-Gisin 2004 (SARG04) QKD protocol, the unconditionally secure key can be extracted from the two-photon component by modifying the classical post-processing procedure in the BB84 protocol. Employing the merits of SARG04 QKD protocol and six-state preparation, one can extract secure key from the components of single photon up to four photons. In this paper, we provide the exact relations between the secure key rate and the bit error rate in a six-state SARG04 protocol with single-photon, two-photon, three-photon, and four-photon sources. By restricting the mutual information between the phase error and bit error, we obtain a higher secure bit error rate threshold of the multiphoton components than previous works. Besides, we compare the performances of the six-state SARG04 with other prepare-and-measure QKD protocols using decoy states. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1607.02366v1-abstract-full').style.display = 'none'; document.getElementById('1607.02366v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 July, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">24 pages 2 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Scientific Reports 6, 29482 (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1602.07385">arXiv:1602.07385</a> <span> [<a href="https://arxiv.org/pdf/1602.07385">pdf</a>, <a href="https://arxiv.org/ps/1602.07385">ps</a>, <a href="https://arxiv.org/format/1602.07385">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.93.022330">10.1103/PhysRevA.93.022330 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Detector-decoy quantum key distribution without monitoring signal disturbance </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Mao%2C+Y">Yingqiu Mao</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="1602.07385v1-abstract-short" style="display: inline;"> The round-robin differential phase-shift quantum key distribution protocol provides a secure way to exchange private information without monitoring conventional disturbances and still maintains a high tolerance of noise, making it desirable for practical implementations of quantum key distribution. However, photon number resolving detectors are required to ensure that the detected signals are sing… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1602.07385v1-abstract-full').style.display = 'inline'; document.getElementById('1602.07385v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1602.07385v1-abstract-full" style="display: none;"> The round-robin differential phase-shift quantum key distribution protocol provides a secure way to exchange private information without monitoring conventional disturbances and still maintains a high tolerance of noise, making it desirable for practical implementations of quantum key distribution. However, photon number resolving detectors are required to ensure that the detected signals are single photons in the original protocol. Here, we adopt the detector-decoy method and give the bounds to the fraction of detected events from single photons. Utilizing the advantages of the protocol, we provide a practical method of performing the protocol with desirable performances requiring only threshold single-photon detectors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1602.07385v1-abstract-full').style.display = 'none'; document.getElementById('1602.07385v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 February, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A 93, 022330 (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1507.03333">arXiv:1507.03333</a> <span> [<a href="https://arxiv.org/pdf/1507.03333">pdf</a>, <a href="https://arxiv.org/ps/1507.03333">ps</a>, <a href="https://arxiv.org/format/1507.03333">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.93.032316">10.1103/PhysRevA.93.032316 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Practical Quantum Digital Signature </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="1507.03333v3-abstract-short" style="display: inline;"> Guaranteeing nonrepudiation, unforgeability as well as transferability of a signature is one of the most vital safeguards in today's e-commerce era. Based on fundamental laws of quantum physics, quantum digital signature (QDS) aims to provide information-theoretic security for this cryptographic task. However, up to date, the previously proposed QDS protocols are impractical due to various challen… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1507.03333v3-abstract-full').style.display = 'inline'; document.getElementById('1507.03333v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1507.03333v3-abstract-full" style="display: none;"> Guaranteeing nonrepudiation, unforgeability as well as transferability of a signature is one of the most vital safeguards in today's e-commerce era. Based on fundamental laws of quantum physics, quantum digital signature (QDS) aims to provide information-theoretic security for this cryptographic task. However, up to date, the previously proposed QDS protocols are impractical due to various challenging problems and most importantly, the requirement of authenticated (secure) quantum channels between participants. Here, we present the first quantum digital signature protocol that removes the assumption of authenticated quantum channels while remaining secure against the collective attacks. Besides, our QDS protocol can be practically implemented over more than 100 km under current mature technology as used in quantum key distribution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1507.03333v3-abstract-full').style.display = 'none'; document.getElementById('1507.03333v3-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 March, 2016; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 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">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 93, 032316 (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1412.0832">arXiv:1412.0832</a> <span> [<a href="https://arxiv.org/pdf/1412.0832">pdf</a>, <a href="https://arxiv.org/ps/1412.0832">ps</a>, <a href="https://arxiv.org/format/1412.0832">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.114.090501">10.1103/PhysRevLett.114.090501 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Long-Distance Measurement-Device-Independent Multiparty Quantum Communication </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+T">Teng-Yun Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="1412.0832v2-abstract-short" style="display: inline;"> The Greenberger-Horne-Zeilinger (GHZ) entanglement, originally introduced to uncover the extreme violation of local realism against quantum mechanics, is an important resource for multiparty quantum communication tasks. But the low intensity and fragility of the GHZ entanglement source in current conditions have made the practical applications of these multiparty tasks an experimental challenge. H… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1412.0832v2-abstract-full').style.display = 'inline'; document.getElementById('1412.0832v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1412.0832v2-abstract-full" style="display: none;"> The Greenberger-Horne-Zeilinger (GHZ) entanglement, originally introduced to uncover the extreme violation of local realism against quantum mechanics, is an important resource for multiparty quantum communication tasks. But the low intensity and fragility of the GHZ entanglement source in current conditions have made the practical applications of these multiparty tasks an experimental challenge. Here we propose a feasible scheme for practically distributing the post-selected GHZ entanglement over a distance of more than 100 km for experimentally accessible parameter regimes. Combining the decoy-state and measurement-device-independent protocols for quantum key distribution, we anticipate that our proposal suggests an important avenue for practical multiparty quantum communication. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1412.0832v2-abstract-full').style.display = 'none'; document.getElementById('1412.0832v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 March, 2015; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 December, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> PRL 114, 090501 (2015) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1409.5728">arXiv:1409.5728</a> <span> [<a href="https://arxiv.org/pdf/1409.5728">pdf</a>, <a href="https://arxiv.org/ps/1409.5728">ps</a>, <a href="https://arxiv.org/format/1409.5728">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OL.39.005451">10.1364/OL.39.005451 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Long distance measurement-device-independent quantum key distribution with coherent-state superpositions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+W">Wen-Fei Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Tang%2C+Y">Yan-Lin Tang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yang Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+T">Teng-Yun Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="1409.5728v1-abstract-short" style="display: inline;"> Measurement-device-independent quantum key distribution (MDI-QKD) with decoy-state method is believed to be securely applied to defeat various hacking attacks in practical quantum key distribution systems. Recently, the coherent-state superpositions (CSS) have emerged as an alternative to single-photon qubits for quantum information processing and metrology. Here, in this Letter, CSS are exploited… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1409.5728v1-abstract-full').style.display = 'inline'; document.getElementById('1409.5728v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1409.5728v1-abstract-full" style="display: none;"> Measurement-device-independent quantum key distribution (MDI-QKD) with decoy-state method is believed to be securely applied to defeat various hacking attacks in practical quantum key distribution systems. Recently, the coherent-state superpositions (CSS) have emerged as an alternative to single-photon qubits for quantum information processing and metrology. Here, in this Letter, CSS are exploited as the source in MDI-QKD. We present an analytical method which gives two tight formulas to estimate the lower bound of yield and the upper bound of bit error rate. We exploit the standard statistical analysis and Chernoff bound to perform the parameter estimation. Chernoff bound can provide good bounds in the long distance MDI-QKD. Our results show that with CSS, both the security transmission distance and secure key rate are significantly improved compared with those of the weak coherent states in the finite-data case. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1409.5728v1-abstract-full').style.display = 'none'; document.getElementById('1409.5728v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 September, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Opt. Lett. 39, 5451(2014) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1409.0437">arXiv:1409.0437</a> <span> [<a href="https://arxiv.org/pdf/1409.0437">pdf</a>, <a href="https://arxiv.org/ps/1409.0437">ps</a>, <a href="https://arxiv.org/format/1409.0437">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.90.022124">10.1103/PhysRevA.90.022124 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Violations of entropic Bell inequalities with coarse-grained quadrature measurements for continuous-variable states </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Yu-Kang Zhao</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="1409.0437v1-abstract-short" style="display: inline;"> It is a long-standing belief, as pointed out by Bell in 1986, that it is impossible to use a two-mode Gaussian state possessing a positive-definite Wigner function to demonstrate nonlocality as the Wigner function itself provides a local hidden-variable model. In particular, when one performs continuous-variable (CV) quadrature measurements upon a routinely generated CV entanglement, namely, the t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1409.0437v1-abstract-full').style.display = 'inline'; document.getElementById('1409.0437v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1409.0437v1-abstract-full" style="display: none;"> It is a long-standing belief, as pointed out by Bell in 1986, that it is impossible to use a two-mode Gaussian state possessing a positive-definite Wigner function to demonstrate nonlocality as the Wigner function itself provides a local hidden-variable model. In particular, when one performs continuous-variable (CV) quadrature measurements upon a routinely generated CV entanglement, namely, the two-mode squeezed vacuum (TMSV) state, the resulting Wigner function is positive-definite and as such, the TMSV state cannot violate any Bell inequality using CV quadrature measurements. We show here, however, that a Bell inequality for CV states in terms of entropies can be quantum mechanically violated by the TMSV state with two coarse-grained quadrature measurements per site within experimentally accessible parameter regime. The proposed CV entropic Bell inequality is advantageous for an experimental test, especially for a possible loophole-free test of nonlocality, as the quadrature measurements can be implemented with homodyne detections of nearly 100\% detection efficiency under current technology. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1409.0437v1-abstract-full').style.display = 'none'; document.getElementById('1409.0437v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 September, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A. 90, 022124 (2014) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1407.7375">arXiv:1407.7375</a> <span> [<a href="https://arxiv.org/pdf/1407.7375">pdf</a>, <a href="https://arxiv.org/ps/1407.7375">ps</a>, <a href="https://arxiv.org/format/1407.7375">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"> Measurement-device-independent quantum key distribution based on Bell's inequality </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Yin%2C+H">Hua-Lei Yin</a>, <a href="/search/quant-ph?searchtype=author&query=Fu%2C+Y">Yao Fu</a>, <a href="/search/quant-ph?searchtype=author&query=Tang%2C+Y">Yan-Lin Tang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yuan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+T">Teng-Yun Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+Z">Zeng-Bing 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="1407.7375v1-abstract-short" style="display: inline;"> We propose two quantum key distribution (QKD) protocols based on Bell's inequality, which can be considered as modified time-reversed E91 protocol. Similar to the measurement-device-independent quantum key distribution (MDI-QKD) protocol, the first scheme requires the assumption that Alice and Bob perfectly characterize the encoded quantum states. However, our second protocol does not require this… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1407.7375v1-abstract-full').style.display = 'inline'; document.getElementById('1407.7375v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1407.7375v1-abstract-full" style="display: none;"> We propose two quantum key distribution (QKD) protocols based on Bell's inequality, which can be considered as modified time-reversed E91 protocol. Similar to the measurement-device-independent quantum key distribution (MDI-QKD) protocol, the first scheme requires the assumption that Alice and Bob perfectly characterize the encoded quantum states. However, our second protocol does not require this assumption, which can defeat more known and unknown source-side attacks compared with the MDI-QKD. The two protocols are naturally immune to all hacking attacks with respect to detections. Therefore, the security of the two protocols can be proven based on the violation of Bell's inequality with measurement data under fair-sampling assumption. In our simulation, the results of both protocols show that long-distance quantum key distribution over 200 km remains secure with conventional lasers in the asymptotic-data case. We present a new technique to estimate the Bell's inequality violation, which can also be applied to other fields of quantum information processing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1407.7375v1-abstract-full').style.display = 'none'; document.getElementById('1407.7375v1-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 July, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2014. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 4 figures</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> 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