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class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.10398">arXiv:2411.10398</a> <span> [<a href="https://arxiv.org/pdf/2411.10398">pdf</a>, <a href="https://arxiv.org/format/2411.10398">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="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Nonlinearity-Driven Morphing and Control of Topological Modes in Non-Hermitian Systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cai%2C+Z">Zhao-Fan Cai</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yu-Chun Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.10398v1-abstract-short" style="display: inline;"> Non-Hermitian skin effect (NHSE) and nonlinearity can each delocalize topological zero modes (TZMs) from the boundary. To overcome the challenge of precise parameter tuning imposed by the NHSE-induced delocalization and to enhance the capacity of TZMs limited by nonlinearity-induced partial delocalization in Hermitian systems, we develop non-Hermitian nonlinear topological interface models. This m… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.10398v1-abstract-full').style.display = 'inline'; document.getElementById('2411.10398v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.10398v1-abstract-full" style="display: none;"> Non-Hermitian skin effect (NHSE) and nonlinearity can each delocalize topological zero modes (TZMs) from the boundary. To overcome the challenge of precise parameter tuning imposed by the NHSE-induced delocalization and to enhance the capacity of TZMs limited by nonlinearity-induced partial delocalization in Hermitian systems, we develop non-Hermitian nonlinear topological interface models. This model consists of both Hermitian and non-Hermitian Su-Schrieffer-Heeger (SSH) chains, incorporating nonreciprocal hopping and nonlinearity. When the nonlinearity is applied to both chains, the TZM becomes fully delocalized, extending across the entire lattice of two chains without the need for precise parameter tuning. By adjusting nonlinear coefficients in both chains, the wavefunction profile and plateaus across the entire lattice can be effectively controlled and customized through inherent configuration and intensity of the nonlinearity. Furthermore, the spectral localizer is utilized to demonstrate the topological protection of these extended non-Hermitian TZMs, confirming their robustness against disorder. Their dynamical stability under external pumping is also validated. Our findings provide a deeper insight into how nonlinearity and NHSE affect the behavior of topological modes, opening new possibilities for enhancing their capacity and performance in compact devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.10398v1-abstract-full').style.display = 'none'; document.getElementById('2411.10398v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 figures in the main text</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.09067">arXiv:2411.09067</a> <span> [<a href="https://arxiv.org/pdf/2411.09067">pdf</a>, <a href="https://arxiv.org/format/2411.09067">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="Quantum Gases">cond-mat.quant-gas</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Critical states exhibit invariance in both position and momentum spaces </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.09067v2-abstract-short" style="display: inline;"> The critical states of disordered systems are intriguing subjects within the realm of condensed matter physics and complex systems. These states manifest in materials where disorder plays a significant role, and are distinguished by their multifractal structure and self-similarity. However, accurately characterizing critical states continues to pose a significant challenge. In this study, we argue… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09067v2-abstract-full').style.display = 'inline'; document.getElementById('2411.09067v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.09067v2-abstract-full" style="display: none;"> The critical states of disordered systems are intriguing subjects within the realm of condensed matter physics and complex systems. These states manifest in materials where disorder plays a significant role, and are distinguished by their multifractal structure and self-similarity. However, accurately characterizing critical states continues to pose a significant challenge. In this study, we argue that critical states exhibit a certain invariance in both position and momentum spaces, leading to their delocalization in both domains. More specifically, it is expected that typical physical quantities characterizing critical states, such as the inverse participation ratio and information entropy, should exhibit invariance in both position space and momentum space. Subsequent numerical simulations validate the correctness of this invariance, thereby establishing a robust foundation for future experimental validation of critical states. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.09067v2-abstract-full').style.display = 'none'; document.getElementById('2411.09067v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Comments are welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.23562">arXiv:2410.23562</a> <span> [<a href="https://arxiv.org/pdf/2410.23562">pdf</a>, <a href="https://arxiv.org/format/2410.23562">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 Secret Sharing Networks with Linear Bell-State Analysis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tianqi Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Lai%2C+J">Jiancheng Lai</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Z">Zhenhua Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tao Li</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.23562v1-abstract-short" style="display: inline;"> Quantum secret sharing (QSS) plays a pivotal role in multiparty quantum communication, ensuring the secure distribution of private information among multiple parties. However, the security of QSS schemes can be compromised by attacks exploiting imperfections in measurement devices. Here, we propose a reconfigurable approach to implement QSS based on measurement-device-independent (MDI) principles,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.23562v1-abstract-full').style.display = 'inline'; document.getElementById('2410.23562v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.23562v1-abstract-full" style="display: none;"> Quantum secret sharing (QSS) plays a pivotal role in multiparty quantum communication, ensuring the secure distribution of private information among multiple parties. However, the security of QSS schemes can be compromised by attacks exploiting imperfections in measurement devices. Here, we propose a reconfigurable approach to implement QSS based on measurement-device-independent (MDI) principles, utilizing linear two-photon Bell state analysis.By employing single-qubit conjugate operations for encoding private information, our approach offers reconfigurability, allowing for the inclusion of additional quantum network nodes without sacrificing efficiency. Furthermore, we demonstrate the robust security of our MDI-QSS scheme against inter-eavesdropping by dishonest participants and establish lower bounds for secure communication among three legitimate parties. This work presents a flexible configuration for implementing multiparty secure quantum communication with imperfect measurement devices and represents a significant advancement in the development of secure quantum communication technologies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.23562v1-abstract-full').style.display = 'none'; document.getElementById('2410.23562v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 3 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.15061">arXiv:2410.15061</a> <span> [<a href="https://arxiv.org/pdf/2410.15061">pdf</a>, <a href="https://arxiv.org/format/2410.15061">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Classifying extended, localized and critical states in quasiperiodic lattices via unsupervised learning </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+B">Bohan Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+S">Siyu Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+X">Xingping Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.15061v1-abstract-short" style="display: inline;"> Classification of quantum phases is one of the most important areas of research in condensed matter physics. In this work, we obtain the phase diagram of one-dimensional quasiperiodic models via unsupervised learning. Firstly, we choose two advanced unsupervised learning algorithms, Density-Based Spatial Clustering of Applications with Noise (DBSCAN) and Ordering Points To Identify the Clustering… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15061v1-abstract-full').style.display = 'inline'; document.getElementById('2410.15061v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.15061v1-abstract-full" style="display: none;"> Classification of quantum phases is one of the most important areas of research in condensed matter physics. In this work, we obtain the phase diagram of one-dimensional quasiperiodic models via unsupervised learning. Firstly, we choose two advanced unsupervised learning algorithms, Density-Based Spatial Clustering of Applications with Noise (DBSCAN) and Ordering Points To Identify the Clustering Structure (OPTICS), to explore the distinct phases of Aubry-Andr茅-Harper model and quasiperiodic p-wave model. The unsupervised learning results match well with traditional numerical diagonalization. Finally, we compare the similarity of different algorithms and find that the highest similarity between the results of unsupervised learning algorithms and those of traditional algorithms has exceeded 98\%. Our work sheds light on applications of unsupervised learning for phase classification. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.15061v1-abstract-full').style.display = 'none'; document.getElementById('2410.15061v1-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.16748">arXiv:2409.16748</a> <span> [<a href="https://arxiv.org/pdf/2409.16748">pdf</a>, <a href="https://arxiv.org/format/2409.16748">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"> Fast unconditional reset and leakage reduction in fixed-frequency transmon qubits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Chen%2C+L">Liangyu Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Fors%2C+S+P">Simon Pettersson Fors</a>, <a href="/search/quant-ph?searchtype=author&query=Yan%2C+Z">Zixian Yan</a>, <a href="/search/quant-ph?searchtype=author&query=Ali%2C+A">Anaida Ali</a>, <a href="/search/quant-ph?searchtype=author&query=Abad%2C+T">Tahereh Abad</a>, <a href="/search/quant-ph?searchtype=author&query=Osman%2C+A">Amr Osman</a>, <a href="/search/quant-ph?searchtype=author&query=Moschandreou%2C+E">Eleftherios Moschandreou</a>, <a href="/search/quant-ph?searchtype=author&query=Lienhard%2C+B">Benjamin Lienhard</a>, <a href="/search/quant-ph?searchtype=author&query=Kosen%2C+S">Sandoko Kosen</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hang-Xi Li</a>, <a href="/search/quant-ph?searchtype=author&query=Shiri%2C+D">Daryoush Shiri</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Hill%2C+S">Stefan Hill</a>, <a href="/search/quant-ph?searchtype=author&query=Amin%2C+A">Abdullah-Al Amin</a>, <a href="/search/quant-ph?searchtype=author&query=Rehammar%2C+R">Robert Rehammar</a>, <a href="/search/quant-ph?searchtype=author&query=Dahiya%2C+M">Mamta Dahiya</a>, <a href="/search/quant-ph?searchtype=author&query=Nylander%2C+A">Andreas Nylander</a>, <a href="/search/quant-ph?searchtype=author&query=Rommel%2C+M">Marcus Rommel</a>, <a href="/search/quant-ph?searchtype=author&query=Roudsari%2C+A+F">Anita Fadavi Roudsari</a>, <a href="/search/quant-ph?searchtype=author&query=Caputo%2C+M">Marco Caputo</a>, <a href="/search/quant-ph?searchtype=author&query=Leif%2C+G">Gr枚nberg Leif</a>, <a href="/search/quant-ph?searchtype=author&query=Govenius%2C+J">Joonas Govenius</a>, <a href="/search/quant-ph?searchtype=author&query=Dobsicek%2C+M">Miroslav Dobsicek</a>, <a href="/search/quant-ph?searchtype=author&query=Giannelli%2C+M+F">Michele Faucci Giannelli</a>, <a href="/search/quant-ph?searchtype=author&query=Kockum%2C+A+F">Anton Frisk Kockum</a> , et al. (2 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2409.16748v2-abstract-short" style="display: inline;"> The realization of fault-tolerant quantum computing requires the execution of quantum error-correction (QEC) schemes, to mitigate the fragile nature of qubits. In this context, to ensure the success of QEC, a protocol capable of implementing both qubit reset and leakage reduction is highly desirable. We demonstrate such a protocol in an architecture consisting of fixed-frequency transmon qubits pa… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.16748v2-abstract-full').style.display = 'inline'; document.getElementById('2409.16748v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.16748v2-abstract-full" style="display: none;"> The realization of fault-tolerant quantum computing requires the execution of quantum error-correction (QEC) schemes, to mitigate the fragile nature of qubits. In this context, to ensure the success of QEC, a protocol capable of implementing both qubit reset and leakage reduction is highly desirable. We demonstrate such a protocol in an architecture consisting of fixed-frequency transmon qubits pair-wise coupled via tunable couplers -- an architecture that is compatible with the surface code. We use tunable couplers to transfer any undesired qubit excitation to the readout resonator of the qubit, from which this excitation decays into the feedline. In total, the combination of qubit reset, leakage reduction, and coupler reset takes only 83ns to complete. Our reset scheme is fast, unconditional, and achieves fidelities well above 99%, thus enabling fixed-frequency qubit architectures as future implementations of fault-tolerant quantum computers. Our protocol also provides a means to both reduce QEC cycle runtime and improve algorithmic fidelity on quantum computers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.16748v2-abstract-full').style.display = 'none'; document.getElementById('2409.16748v2-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 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.15379">arXiv:2409.15379</a> <span> [<a href="https://arxiv.org/pdf/2409.15379">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Irreversible Diagonalization of Mechanical Quantities and the EPR Paradox </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2409.15379v1-abstract-short" style="display: inline;"> The closure relation of quantum mechanical projection operators is not entirely true; it can be strictly falsified under unitary transformations in Fock states. The angular momentum $J_x$, $J_y$ and $J_z$ are simultaneously diagonalized under the orthonormal set $\{|蠁_n\rangle\}$ of continuous rotation transformations in Fock states. $\{|蠁_n\rangle\}$'s time reversal… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.15379v1-abstract-full').style.display = 'inline'; document.getElementById('2409.15379v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.15379v1-abstract-full" style="display: none;"> The closure relation of quantum mechanical projection operators is not entirely true; it can be strictly falsified under unitary transformations in Fock states. The angular momentum $J_x$, $J_y$ and $J_z$ are simultaneously diagonalized under the orthonormal set $\{|蠁_n\rangle\}$ of continuous rotation transformations in Fock states. $\{|蠁_n\rangle\}$'s time reversal $\{ \mathcal{T} |蠁_n\rangle \}$ is the zero point of coordinates q and momentum p, and its arbitrary translation transformation $\{ \mathcal{D} \mathcal{T} |蠁_n\rangle \}$ diagonalizes both coordinates and momentum simultaneously. The abstract representation of the Dirac state vector implies the symmetry breaking of the non-Abelian group unit matrix $\{ \mathcal{U}^ \mathcal{H} \mathcal{U} \neq \mathcal{U} \mathcal{U} ^\mathcal{H} \}$. The EPR paradox is merely a fallacy under the reversible diagonalization of physical reality, it is resolved under irreversible diagonalization. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.15379v1-abstract-full').style.display = 'none'; document.getElementById('2409.15379v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2409.12581">arXiv:2409.12581</a> <span> [<a href="https://arxiv.org/pdf/2409.12581">pdf</a>, <a href="https://arxiv.org/format/2409.12581">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Quantum synchronization in one-dimensional topological systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2409.12581v1-abstract-short" style="display: inline;"> The phenomenon of synchronization, where entities exhibit stable oscillations with aligned frequencies and phases, has been detected in diverse areas of natural science. It plays a crucial role in achieving frequency locking in multiple applications such as microwave communication and signal processing. The study of synchronization in quantum systems has gained significant interest, particularly i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.12581v1-abstract-full').style.display = 'inline'; document.getElementById('2409.12581v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.12581v1-abstract-full" style="display: none;"> The phenomenon of synchronization, where entities exhibit stable oscillations with aligned frequencies and phases, has been detected in diverse areas of natural science. It plays a crucial role in achieving frequency locking in multiple applications such as microwave communication and signal processing. The study of synchronization in quantum systems has gained significant interest, particularly in developing robust methods for synchronizing distant objects. Here, we demonstrate that synchronization between the boundary sites of one-dimensional generalized Aubry-Andr茅-Harper models can be induced through applying dissipation on the central sites. Two types of synchronization, stemming from the topological edge states, are characterized by the off-diagonal or diagonal correlations between the boundary sites. We analyze the relaxation rate to realize the synchronization and its acceleration with bulk dissipation. Remarkably, the synchronous oscillations maintain steady amplitude and frequency in the thermodynamic limit. Moreover, we show that the synchronization is robust against the perturbations in the Hamiltonian and initial states, highlighting its potential for practical implementation in quantum networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.12581v1-abstract-full').style.display = 'none'; document.getElementById('2409.12581v1-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.16205">arXiv:2408.16205</a> <span> [<a href="https://arxiv.org/pdf/2408.16205">pdf</a>, <a href="https://arxiv.org/format/2408.16205">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"> Demonstrating two-particle interference with a one-dimensional delta potential well </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Deng%2C+Z+J">Zhi Jiao Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+X">Xin Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Shen%2C+Y">Yong Shen</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+W+T">Wei Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+P+X">Ping Xing 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="2408.16205v1-abstract-short" style="display: inline;"> In quantum mechanics, the exchange symmetry of wave functions for identical particles has observable effects, including the widely studied Hong-Ou-Mandel (HOM) effect. A theoretical description using second quantization is elegant but abstract. In contrast, this paper describes a simple model of two-particle interference using a one-dimensional delta potential well as a beam splitter. The conditio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.16205v1-abstract-full').style.display = 'inline'; document.getElementById('2408.16205v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.16205v1-abstract-full" style="display: none;"> In quantum mechanics, the exchange symmetry of wave functions for identical particles has observable effects, including the widely studied Hong-Ou-Mandel (HOM) effect. A theoretical description using second quantization is elegant but abstract. In contrast, this paper describes a simple model of two-particle interference using a one-dimensional delta potential well as a beam splitter. The conditions for the HOM effect are derived from the perspective of wave packet evolution. Furthermore, the interference processes of bosons, fermions and distinguishable particles are demonstrated and compared in detail. The method presented here is concrete, easy to visualize, and can help students to better understand the effects arising from the exchange symmetry of wave functions. The main results can be animated for classroom teaching or developed into an undergraduate seminar topic. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.16205v1-abstract-full').style.display = 'none'; document.getElementById('2408.16205v1-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 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.12451">arXiv:2408.12451</a> <span> [<a href="https://arxiv.org/pdf/2408.12451">pdf</a>, <a href="https://arxiv.org/format/2408.12451">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Gases">cond-mat.quant-gas</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <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"> Dissipation and Interaction-Controlled Non-Hermitian Skin Effects </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Cai%2C+Z">Zhao-Fan Cai</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Nori%2C+F">Franco Nori</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.12451v2-abstract-short" style="display: inline;"> Non-Hermitian skin effects (NHSEs) have recently been investigated extensively at the single-particle level. When many-body interactions become dominant, novel non-Hermitian physical phenomena can emerge. In this work, we theoretically study NHSEs controlled by dissipation and interaction. We consider a 1D zigzag Bose-Hubbard lattice, subject to magnetic flux, staggered onsite single-particle loss… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.12451v2-abstract-full').style.display = 'inline'; document.getElementById('2408.12451v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.12451v2-abstract-full" style="display: none;"> Non-Hermitian skin effects (NHSEs) have recently been investigated extensively at the single-particle level. When many-body interactions become dominant, novel non-Hermitian physical phenomena can emerge. In this work, we theoretically study NHSEs controlled by dissipation and interaction. We consider a 1D zigzag Bose-Hubbard lattice, subject to magnetic flux, staggered onsite single-particle loss, and uniform onsite two-particle loss. When the two-particle loss is small, two-body bound eigenstates (i.e., doublons) are all localized at the same boundary due to the interplay of the magnetic flux and staggered single-particle loss. While, for strong two-particle loss, the localization direction of doublons is unexpectedly reversed. This is attributed to the effective strong nonreciprocal hopping of doublons contributing from the virtual second-order and third-order hopping processes of particle pairs in combination with the magnetic flux, the strong two-particle loss, and the many-body interaction. Moreover, a two-particle gain can induce the same skin-localization of doublons, which can be utilized to dynamically observe the NHSE and its reversal of doublons controlled by interactions. Our results open up a new avenue for exploring novel non-Hermitian phenomena in many-body systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.12451v2-abstract-full').style.display = 'none'; document.getElementById('2408.12451v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 9 figures; Comments are welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.07603">arXiv:2408.07603</a> <span> [<a href="https://arxiv.org/pdf/2408.07603">pdf</a>, <a href="https://arxiv.org/format/2408.07603">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"> Chiral-Extended Photon-Emitter Dressed States in Non-Hermitian Topological Baths </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cai%2C+Z">Zhao-Fan Cai</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+Z">Zi-Xuan Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Nori%2C+F">Franco Nori</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.07603v2-abstract-short" style="display: inline;"> The interplay of quantum emitters and non-Hermitian structured baths has received increasing attention in recent years. Here, we predict unconventional quantum optical behaviors of quantum emitters coupled to a non-Hermitian topological bath, which is realized in a 1D Su-Schrieffer-Heeger photonic chain subjected to nonlocal dissipation. In addition to the Hermitian-like chiral bound states in the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07603v2-abstract-full').style.display = 'inline'; document.getElementById('2408.07603v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.07603v2-abstract-full" style="display: none;"> The interplay of quantum emitters and non-Hermitian structured baths has received increasing attention in recent years. Here, we predict unconventional quantum optical behaviors of quantum emitters coupled to a non-Hermitian topological bath, which is realized in a 1D Su-Schrieffer-Heeger photonic chain subjected to nonlocal dissipation. In addition to the Hermitian-like chiral bound states in the middle line gap and skin-mode-like hidden bound states inside the point gap, we identify peculiar in-gap chiral and extended photon-emitter dressed states. This is due to the competition of topological-edge localization and non-Hermitian skin-mode localization in combination with the non-Bloch bulk-boundary correspondence. Furthermore, when two emitters are coupled to the same bath, such in-gap dressed states can mediate the nonreciprocal long-range emitter-emitter interactions, with the interaction range limited only by the dissipation of the bath. Our work opens the door to further study rich quantum optical phenomena and exotic many-body physics utilizing quantum emitters coupled to non-Hermitian topological baths. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.07603v2-abstract-full').style.display = 'none'; document.getElementById('2408.07603v2-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 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">22 pages, 10 figures; Comments are welcome</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.04876">arXiv:2408.04876</a> <span> [<a href="https://arxiv.org/pdf/2408.04876">pdf</a>, <a href="https://arxiv.org/format/2408.04876">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Gases">cond-mat.quant-gas</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Entanglement Witness for Indistinguishable Electrons using Solid-State Spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tongtong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+L">Luogen Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+J">Jiarui Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yao 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="2408.04876v1-abstract-short" style="display: inline;"> Characterizing entanglement in quantum materials is crucial for advancing next-generation quantum technologies. Despite recent strides in witnessing entanglement in magnetic materials with distinguishable spin modes, quantifying entanglement in systems formed by indistinguishable electrons remains a formidable challenge. To solve this problem, we introduce a method to extract various four-fermion… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.04876v1-abstract-full').style.display = 'inline'; document.getElementById('2408.04876v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.04876v1-abstract-full" style="display: none;"> Characterizing entanglement in quantum materials is crucial for advancing next-generation quantum technologies. Despite recent strides in witnessing entanglement in magnetic materials with distinguishable spin modes, quantifying entanglement in systems formed by indistinguishable electrons remains a formidable challenge. To solve this problem, we introduce a method to extract various four-fermion correlations by analyzing the nonlinearity in resonant inelastic X-ray scattering (RIXS) spectra. These correlations constitute the primary components of the cumulant two-particle reduced density matrix (RDM). We further derive bounds for its eigenvalues and demonstrate the linear scaling with fermionic entanglement depth, providing a reliable witness for entanglement. Using the material-relevant strongly correlated models as examples, we show how this this entanglement witness can efficiently quantify multipartite entanglement across different phase regions, highlighting its advantage over quantum Fisher information (QFI). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.04876v1-abstract-full').style.display = 'none'; document.getElementById('2408.04876v1-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 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">28 pages, 15 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.01155">arXiv:2408.01155</a> <span> [<a href="https://arxiv.org/pdf/2408.01155">pdf</a>, <a href="https://arxiv.org/format/2408.01155">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Efficient conversion from fermionic Gaussian states to matrix product states </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+Y">Ying-Hai Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Tu%2C+H">Hong-Hao Tu</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+T">Tao 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="2408.01155v1-abstract-short" style="display: inline;"> Fermionic Gaussian states are eigenstates of quadratic Hamiltonians and widely used in quantum many-body problems. We propose a highly efficient algorithm that converts fermionic Gaussian states to matrix product states. It can be formulated for finite-size systems without translation invariance, but becomes particularly appealing when applied to infinite systems with translation invariance. If th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.01155v1-abstract-full').style.display = 'inline'; document.getElementById('2408.01155v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.01155v1-abstract-full" style="display: none;"> Fermionic Gaussian states are eigenstates of quadratic Hamiltonians and widely used in quantum many-body problems. We propose a highly efficient algorithm that converts fermionic Gaussian states to matrix product states. It can be formulated for finite-size systems without translation invariance, but becomes particularly appealing when applied to infinite systems with translation invariance. If the ground states of a topologically ordered system on infinite cylinders are expressed as matrix product states, then the fixed points of the transfer matrix can be harnessed to filter out the anyon eigenbasis, also known as minimally entangled states. This allows for efficient computation of universal properties such as entanglement spectrum and modular matrices. The potential of our method is demonstrated by numerical calculations in two chiral spin liquids that have the same topological orders as the bosonic Laughlin and Moore-Read states, respectively. The anyon eigenbasis for the first one has been worked out before and serves as a useful benchmark. The anyon eigenbasis of the second one is, however, not transparent and its successful construction provides a nontrivial corroboration of our method. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.01155v1-abstract-full').style.display = 'none'; document.getElementById('2408.01155v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 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/2407.02787">arXiv:2407.02787</a> <span> [<a href="https://arxiv.org/pdf/2407.02787">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> A versatile quantum microwave photonic signal processing platform based on coincidence window selection technique </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xinghua Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+Y">Yifan Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+X">Xiao Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Quan%2C+R">Runai Quan</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+M">Mingtao Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+R">Ruifang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+M">Ming Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+S">Shougang 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="2407.02787v1-abstract-short" style="display: inline;"> Quantum microwave photonics (QMWP) is an innovative approach that combines energy-time entangled biphoton sources as the optical carrier with time-correlated single-photon detection for high-speed RF signal recovery. This groundbreaking method offers unique advantages such as nonlocal RF signal encoding and robust resistance to dispersion-induced frequency fading. This paper explores the versatili… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.02787v1-abstract-full').style.display = 'inline'; document.getElementById('2407.02787v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.02787v1-abstract-full" style="display: none;"> Quantum microwave photonics (QMWP) is an innovative approach that combines energy-time entangled biphoton sources as the optical carrier with time-correlated single-photon detection for high-speed RF signal recovery. This groundbreaking method offers unique advantages such as nonlocal RF signal encoding and robust resistance to dispersion-induced frequency fading. This paper explores the versatility of processing the quantum microwave photonic signal by utilizing coincidence window selection on the biphoton coincidence distribution. The demonstration includes finely-tunable RF phase shifting, flexible multi-tap transversal filtering (with up to 15 taps), and photonically implemented RF mixing, leveraging the nonlocal RF mapping characteristic of QMWP. These accomplishments significantly enhance the capability of microwave photonic systems in processing ultra-weak signals, opening up new possibilities for various applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.02787v1-abstract-full').style.display = 'none'; document.getElementById('2407.02787v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 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/2407.02774">arXiv:2407.02774</a> <span> [<a href="https://arxiv.org/pdf/2407.02774">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Quantum microwave photonic mixer with a large spurious-free dynamic range </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xinghua Li</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+Y">Yifan Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+X">Xiao Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Quan%2C+R">Runai Quan</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+M">Mingtao Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+R">Ruifang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+M">Ming Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+S">Shougang 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="2407.02774v1-abstract-short" style="display: inline;"> As one of the most fundamental functionalities of microwave photonics, microwave frequency mixing plays an essential role in modern radars and wireless communication systems. However, the commonly utilized intensity modulation in the systems often leads to inadequate spurious-free dynamic range (SFDR) for many sought-after applications. Quantum microwave photonics technique offers a promising solu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.02774v1-abstract-full').style.display = 'inline'; document.getElementById('2407.02774v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.02774v1-abstract-full" style="display: none;"> As one of the most fundamental functionalities of microwave photonics, microwave frequency mixing plays an essential role in modern radars and wireless communication systems. However, the commonly utilized intensity modulation in the systems often leads to inadequate spurious-free dynamic range (SFDR) for many sought-after applications. Quantum microwave photonics technique offers a promising solution for improving SFDR in terms of higher-order harmonic distortion. In this paper, we demonstrate two types of quantum microwave photonic mixers based on the configuration of the intensity modulators: cascade-type and parallel-type. Leveraging the nonlocal RF signal encoding capability, both types of quantum microwave photonic mixers not only exhibit the advantage of dual-channel output but also present significant improvement in SFDR. Specifically, the parallel-type quantum microwave photonic mixer achieves a remarkable SFDR value of 113.6 dB.Hz1/2, which is 30 dB better than that of the cascade-type quantum microwave photonic mixer. When compared to the classical microwave photonic mixer, this enhancement reaches a notable 53.6 dB at the expense of 8 dB conversion loss. These results highlight the superiority of quantum microwave photonic mixers in the fields of microwave and millimeter-wave systems. Further applying multi-photon frequency entangled sources as optical carriers, the dual-channel microwave frequency conversion capability endowed by the quantum microwave photonic mixer can be extended to enhance the performance of multiple-paths microwave mixing which is essential for radar net systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.02774v1-abstract-full').style.display = 'none'; document.getElementById('2407.02774v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 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/2407.01196">arXiv:2407.01196</a> <span> [<a href="https://arxiv.org/pdf/2407.01196">pdf</a>, <a href="https://arxiv.org/format/2407.01196">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"> Implementation of a scalable universal two-qubit quantum processor with electron and nuclear spins in a trapped ion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Bian%2C+J">Ji Bian</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Teng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Lao%2C+Q">Qifeng Lao</a>, <a href="/search/quant-ph?searchtype=author&query=Ding%2C+M">Min Ding</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+H">Huiyi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Rao%2C+X">Xinxin Rao</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+P">Pengfei Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Luo%2C+L">Le Luo</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2407.01196v1-abstract-short" style="display: inline;"> Increasing the quantum information processing power with limited number of hosts is vital for achieving quantum advantage. Here we propose a novel scheme that achieves a scalable n-ion-2n-qubit quantum processor utilizing four internal levels of each ion, and experimentally implement a 1-ion-2-qubit universal processor using the valence electron spin and nuclear spin of a single 171Yb+ ion. Fideli… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.01196v1-abstract-full').style.display = 'inline'; document.getElementById('2407.01196v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.01196v1-abstract-full" style="display: none;"> Increasing the quantum information processing power with limited number of hosts is vital for achieving quantum advantage. Here we propose a novel scheme that achieves a scalable n-ion-2n-qubit quantum processor utilizing four internal levels of each ion, and experimentally implement a 1-ion-2-qubit universal processor using the valence electron spin and nuclear spin of a single 171Yb+ ion. Fidelities of single-qubit and two-qubit gates are around 0.98 obtained by quantum process tomography. Additionally, the Grover's algorithm is implemented with a successful rate exceeding 0.99. We provide explicit scaling-up protocols based on standard laser-less and laser-based frameworks, and further demonstrate that the electron/nuclear-spin scheme allows less demanding two-qubit entangling gates between different ions. The replacement of some inter-atomic gates by intra-atomic gates could increase the fidelity of some quantum circuits. Our work paves the way towards achieving 2n-times increase in the size of quantum computational Hilbert space with n ions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.01196v1-abstract-full').style.display = 'none'; document.getElementById('2407.01196v1-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 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/2406.06961">arXiv:2406.06961</a> <span> [<a href="https://arxiv.org/pdf/2406.06961">pdf</a>, <a href="https://arxiv.org/format/2406.06961">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Physics - Theory">hep-th</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Non-Hermitian spacetime and generalized thermofield double formalism </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Guo%2C+W">Wu-zhong Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.06961v1-abstract-short" style="display: inline;"> In this paper, we explore the non-Hermitian transition matrix and its gravity dual. States in quantum field theories or gravity theories are typically prepared using Euclidean path integrals. We demonstrate that it is both natural and necessary to introduce non-Hermitian transitions to describe the state when employing different inner products in Euclidean quantum field theories. Transition matric… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.06961v1-abstract-full').style.display = 'inline'; document.getElementById('2406.06961v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.06961v1-abstract-full" style="display: none;"> In this paper, we explore the non-Hermitian transition matrix and its gravity dual. States in quantum field theories or gravity theories are typically prepared using Euclidean path integrals. We demonstrate that it is both natural and necessary to introduce non-Hermitian transitions to describe the state when employing different inner products in Euclidean quantum field theories. Transition matrices that are $畏$-pseudo-Hermitian, with $畏$ being positive-definite, play the same role as density matrices, where the operator $畏$ is closely related to the definition of the inner product. Moreover, there exists a one-to-one correspondence between these transition matrices and density matrices. In the context of AdS/CFT correspondence, the Euclidean path integral in the boundary field theory can be translated to the bulk gravitational path integral. We provide an overview of the construction and interpretation of non-Hermitian spacetime. Specifically, we demonstrate the crucial role of the non-Hermitian transition matrix in realizing the thermofield concept in general cases and in understanding the gravity states dual to the eternal black hole. In this context, the pseudoentropy of the transition matrix can also be interpreted as black hole entropy. Finally, we highlight the strong subadditivity property of pseudoentropy, and the connection between non-Hermitian transition matrices and complex metrics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.06961v1-abstract-full').style.display = 'none'; document.getElementById('2406.06961v1-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 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">35 pages</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.03026">arXiv:2406.03026</a> <span> [<a href="https://arxiv.org/pdf/2406.03026">pdf</a>, <a href="https://arxiv.org/format/2406.03026">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"> Dynamical topology of chiral and nonreciprocal state transfers in a non-Hermitian quantum system </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Lu%2C+P">Pengfei Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yang Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Lao%2C+Q">Qifeng Lao</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Teng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Rao%2C+X">Xinxin Rao</a>, <a href="/search/quant-ph?searchtype=author&query=Bian%2C+J">Ji Bian</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+H">Hao Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+F">Feng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Luo%2C+L">Le Luo</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.03026v1-abstract-short" style="display: inline;"> The fundamental concept underlying topological phenomena posits the geometric phase associated with eigenstates. In contrast to this prevailing notion, theoretical studies on time-varying Hamiltonians allow for a new type of topological phenomenon, known as topological dynamics, where the evolution process allows a hidden topological invariant associated with continuous flows. To validate this con… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.03026v1-abstract-full').style.display = 'inline'; document.getElementById('2406.03026v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.03026v1-abstract-full" style="display: none;"> The fundamental concept underlying topological phenomena posits the geometric phase associated with eigenstates. In contrast to this prevailing notion, theoretical studies on time-varying Hamiltonians allow for a new type of topological phenomenon, known as topological dynamics, where the evolution process allows a hidden topological invariant associated with continuous flows. To validate this conjecture, we study topological chiral and nonreciprocal dynamics by encircling the exceptional points (EPs) of non-Hermitian Hamiltonians in a trapped ion system. These dynamics are topologically robust against external perturbations even in the presence dissipation-induced nonadiabatic processes. Our findings indicate that they are protected by dynamical vorticity -- an emerging topological invariant associated with the energy dispersion of non-Hermitian band structures in a parallel transported eigenbasis. The symmetry breaking and other key features of topological dynamics are directly observed through quantum state tomography. Our results mark a significant step towards exploring topological properties of open quantum systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.03026v1-abstract-full').style.display = 'none'; document.getElementById('2406.03026v1-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/2404.19216">arXiv:2404.19216</a> <span> [<a href="https://arxiv.org/pdf/2404.19216">pdf</a>, <a href="https://arxiv.org/format/2404.19216">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.110.022428">10.1103/PhysRevA.110.022428 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Optimal quantum strategy for locating Unruh channels </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Q">Qianqian Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tonghua Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wen%2C+C">Cuihong Wen</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jieci 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="2404.19216v1-abstract-short" style="display: inline;"> From the perspective of quantum information theory, the effect of Unruh radiation on a two-level accelerated detector can be modeled as a quantum channel. In this work, we employ the tools of channel-position finding to locate Unruh channels. The signal-idler and idler-free protocols are explored to determine the position of the target Unruh channel within a sequence of background channels. We der… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.19216v1-abstract-full').style.display = 'inline'; document.getElementById('2404.19216v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.19216v1-abstract-full" style="display: none;"> From the perspective of quantum information theory, the effect of Unruh radiation on a two-level accelerated detector can be modeled as a quantum channel. In this work, we employ the tools of channel-position finding to locate Unruh channels. The signal-idler and idler-free protocols are explored to determine the position of the target Unruh channel within a sequence of background channels. We derive the fidelity-based bounds for the ultimate error probability of each strategy and obtain the conditions where the signal-idler protocol is superior to the protocol involving idler-free states. It is found that the lower bound of the error probability for the signal-idler scheme exhibits clear advantages in all cases, while the idler-free scheme can only be implemented when the temperature of the two channels is very close and the number of initial states is insufficient. Interestingly, it is shown that the optimal detection protocol relies on the residual correlations shared between the emitted probe state and the retained idler modes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.19216v1-abstract-full').style.display = 'none'; document.getElementById('2404.19216v1-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 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 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. A 110, 022428 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.18686">arXiv:2404.18686</a> <span> [<a href="https://arxiv.org/pdf/2404.18686">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Dynamic temperature compensation for wavelength-stable entangled biphoton generation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yuting Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Hong%2C+H">Huibo Hong</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+X">Xiao Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Quan%2C+R">Runai Quan</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+M">Mingtao Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+S">Shougang Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+R">Ruifang Dong</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.18686v1-abstract-short" style="display: inline;"> A dynamic temperature compensation method is presented to stabilize the wavelength of the entangled biphoton source, which is generated via the spontaneous parametric down-conversion based on a MgO: PPLN waveguide. Utilizing the dispersive Fourier transformation technique combined with a digital proportional-integral-differential algorithm, the small amount of wavelength variation can be instantly… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.18686v1-abstract-full').style.display = 'inline'; document.getElementById('2404.18686v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.18686v1-abstract-full" style="display: none;"> A dynamic temperature compensation method is presented to stabilize the wavelength of the entangled biphoton source, which is generated via the spontaneous parametric down-conversion based on a MgO: PPLN waveguide. Utilizing the dispersive Fourier transformation technique combined with a digital proportional-integral-differential algorithm, the small amount of wavelength variation can be instantly identified and then compensated with active temperature correction. The long-term wavelength stability, assessed though Allan deviation, shows nearly a hundredfold enhancement, reaching 2.00*10^(-7) at the averaging time of 10000 s. It offers a simple, ready-to-use solution for precise wavelength control in quantum information processing. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.18686v1-abstract-full').style.display = 'none'; document.getElementById('2404.18686v1-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 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.15180">arXiv:2404.15180</a> <span> [<a href="https://arxiv.org/pdf/2404.15180">pdf</a>, <a href="https://arxiv.org/ps/2404.15180">ps</a>, <a href="https://arxiv.org/format/2404.15180">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</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"> Does anti-Unruh effect assist quantum entanglement and coherence? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wu%2C+S">Shu-Min Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Teng%2C+X">Xiao-Wei Teng</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+J">Jin-Xuan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zeng%2C+H">Hao-Sheng Zeng</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tonghua Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.15180v1-abstract-short" style="display: inline;"> In this paper, we use the concepts of quantum entanglement and coherence to analyze the Unruh and anti-Unruh effects based on the model of Unruh-DeWitt detector. For the first time, we find that (i) the Unruh effect reduces quantum entanglement but enhances quantum coherence; (ii) the anti-Unruh effect enhances quantum entanglement but reduces quantum coherence. This surprising result refutes the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.15180v1-abstract-full').style.display = 'inline'; document.getElementById('2404.15180v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.15180v1-abstract-full" style="display: none;"> In this paper, we use the concepts of quantum entanglement and coherence to analyze the Unruh and anti-Unruh effects based on the model of Unruh-DeWitt detector. For the first time, we find that (i) the Unruh effect reduces quantum entanglement but enhances quantum coherence; (ii) the anti-Unruh effect enhances quantum entanglement but reduces quantum coherence. This surprising result refutes the notion that the Unruh effect can only destroy quantum entanglement and coherence simultaneously, and that the anti-Unruh can only protect quantum resources. Consequently, it opens up a new source for discovering experimental evidence supporting the existence of the Unruh and anti-Unruh effects. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.15180v1-abstract-full').style.display = 'none'; document.getElementById('2404.15180v1-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 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 2 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> New J. Phys. 26 (2024) 043016 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.09829">arXiv:2404.09829</a> <span> [<a href="https://arxiv.org/pdf/2404.09829">pdf</a>, <a href="https://arxiv.org/format/2404.09829">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"> Nonlinear chiral quantum optics with giant-emitter pairs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+J">Jia-Qi Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Zhihai Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Kockum%2C+A+F">Anton Frisk Kockum</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+L">Lei Du</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Nori%2C+F">Franco Nori</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="2404.09829v1-abstract-short" style="display: inline;"> We propose a setup which combines giant emitters (coupling to light at multiple points separated by wavelength distances) with nonlinear quantum optics and its correlated photons. In this setup, we reveal a mechanism for multiphoton chiral emission: the propagation phase of the center of mass of two strongly correlated photons (a doublon), and the phases encoded in the coupling points of two giant… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.09829v1-abstract-full').style.display = 'inline'; document.getElementById('2404.09829v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.09829v1-abstract-full" style="display: none;"> We propose a setup which combines giant emitters (coupling to light at multiple points separated by wavelength distances) with nonlinear quantum optics and its correlated photons. In this setup, we reveal a mechanism for multiphoton chiral emission: the propagation phase of the center of mass of two strongly correlated photons (a doublon), and the phases encoded in the coupling points of two giant emitters, can yield completely destructive interference in one propagation direction while supporting emission in the other direction. The degree of chirality can be tuned by the phases of the couplings. We show that the proposed setup can provide directional quantum many-body resources, and can be configured as a building block for a chiral quantum network with ``correlated flying qubits'', enabling distinct applications beyond linear chiral setups. Our findings point toward a rich landscape of tailoring multiphoton propagation and correlation properties by exploiting interference effects of giant emitters coupling to nonlinear photonic baths. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.09829v1-abstract-full').style.display = 'none'; document.getElementById('2404.09829v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">26 pages; 12 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.18964">arXiv:2403.18964</a> <span> [<a href="https://arxiv.org/pdf/2403.18964">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Chirality-Induced Magnet-Free Spin Generation in a Semiconductor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tianhan Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Adhikari%2C+Y">Yuwaraj Adhikari</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+H">Hailong Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Jiang%2C+Y">Yiyang Jiang</a>, <a href="/search/quant-ph?searchtype=author&query=Hua%2C+Z">Zhenqi Hua</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+H">Haoyang Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Schlottmann%2C+P">Pedro Schlottmann</a>, <a href="/search/quant-ph?searchtype=author&query=Gao%2C+H">Hanwei Gao</a>, <a href="/search/quant-ph?searchtype=author&query=Weiss%2C+P+S">Paul S. Weiss</a>, <a href="/search/quant-ph?searchtype=author&query=Yan%2C+B">Binghai Yan</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+J">Jianhua Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Xiong%2C+P">Peng Xiong</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.18964v1-abstract-short" style="display: inline;"> Electrical generation and transduction of polarized electron spins in semiconductors are of central interest in spintronics and quantum information science. While spin generation in semiconductors has been frequently realized via electrical injection from a ferromagnet, there are significant advantages in nonmagnetic pathways of creating spin polarization. One such pathway exploits the interplay o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.18964v1-abstract-full').style.display = 'inline'; document.getElementById('2403.18964v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.18964v1-abstract-full" style="display: none;"> Electrical generation and transduction of polarized electron spins in semiconductors are of central interest in spintronics and quantum information science. While spin generation in semiconductors has been frequently realized via electrical injection from a ferromagnet, there are significant advantages in nonmagnetic pathways of creating spin polarization. One such pathway exploits the interplay of electron spin with chirality in electronic structures or real space. Here, utilizing chirality-induced spin selectivity (CISS), we demonstrate efficient creation of spin accumulation in n-doped GaAs via electric current injection from a normal metal (Au) electrode through a self-assembled monolayer of chiral molecules (伪-helix L-polyalanine, AHPA-L). The resulting spin polarization is detected as a Hanle effect in the n-GaAs, which is found to obey a distinct universal scaling with temperature and bias current consistent with chirality-induced spin accumulation. The experiment constitutes a definitive observation of CISS in a fully nonmagnetic device structure and demonstration of its ability to generate spin accumulation in a conventional semiconductor. The results thus place key constraints on the physical mechanism of CISS and present a new scheme for magnet-free semiconductor spintronics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.18964v1-abstract-full').style.display = 'none'; document.getElementById('2403.18964v1-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, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.16070">arXiv:2402.16070</a> <span> [<a href="https://arxiv.org/pdf/2402.16070">pdf</a>, <a href="https://arxiv.org/format/2402.16070">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"> High-order topological pumping on a superconducting quantum processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Deng%2C+C">Cheng-Lin Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yu Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yu-Ran Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xue-Gang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+C">Chi-Tong Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+C">Cong-Wei Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yong-Yi Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tian-Ming Li</a>, <a href="/search/quant-ph?searchtype=author&query=Fang%2C+C">Cai-Ping Fang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+S">Si-Yun Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+J">Jia-Cheng Song</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+Y">Yue-Shan Xu</a>, <a href="/search/quant-ph?searchtype=author&query=He%2C+Y">Yang He</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zheng-He Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+K">Kai-Xuan Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+Z">Zhong-Cheng Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jie-Ci Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+D">Dong-Ning Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Xue%2C+G">Guang-Ming Xue</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+K">Kai Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+H+F">H. F. Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+H">Heng Fan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.16070v1-abstract-short" style="display: inline;"> High-order topological phases of matter refer to the systems of $n$-dimensional bulk with the topology of $m$-th order, exhibiting $(n-m)$-dimensional boundary modes and can be characterized by topological pumping. Here, we experimentally demonstrate two types of second-order topological pumps, forming four 0-dimensional corner localized states on a 4$\times$4 square lattice array of 16 supercondu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.16070v1-abstract-full').style.display = 'inline'; document.getElementById('2402.16070v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.16070v1-abstract-full" style="display: none;"> High-order topological phases of matter refer to the systems of $n$-dimensional bulk with the topology of $m$-th order, exhibiting $(n-m)$-dimensional boundary modes and can be characterized by topological pumping. Here, we experimentally demonstrate two types of second-order topological pumps, forming four 0-dimensional corner localized states on a 4$\times$4 square lattice array of 16 superconducting qubits. The initial ground state of the system for half-filling, as a product of four identical entangled 4-qubit states, is prepared using an adiabatic scheme. During the pumping procedure, we adiabatically modulate the superlattice Bose-Hubbard Hamiltonian by precisely controlling both the hopping strengths and on-site potentials. At the half pumping period, the system evolves to a corner-localized state in a quadrupole configuration. The robustness of the second-order topological pump is also investigated by introducing different on-site disorder. Our work studies the topological properties of high-order topological phases from the dynamical transport picture using superconducting qubits, which would inspire further research on high-order topological phases. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.16070v1-abstract-full').style.display = 'none'; document.getElementById('2402.16070v1-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 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.07224">arXiv:2402.07224</a> <span> [<a href="https://arxiv.org/pdf/2402.07224">pdf</a>, <a href="https://arxiv.org/format/2402.07224">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"> Arbitrarily configurable nonlinear topological modes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Bai%2C+K">Kai Bai</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+J">Jia-Zheng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tian-Rui Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Fang%2C+L">Liang Fang</a>, <a href="/search/quant-ph?searchtype=author&query=Wan%2C+D">Duanduan Wan</a>, <a href="/search/quant-ph?searchtype=author&query=Xiao%2C+M">Meng Xiao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.07224v1-abstract-short" style="display: inline;"> Topological modes (TMs) are typically localized at boundaries, interfaces and dislocations, and exponentially decay into the bulk of a large enough lattice. Recently, the non-Hermitian skin effect has been leveraged to delocalize the wavefunctions of TMs from the boundary and thus to increase the capacity of TMs dramatically. Here, we explore the capability of nonlinearity in designing and reconfi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07224v1-abstract-full').style.display = 'inline'; document.getElementById('2402.07224v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.07224v1-abstract-full" style="display: none;"> Topological modes (TMs) are typically localized at boundaries, interfaces and dislocations, and exponentially decay into the bulk of a large enough lattice. Recently, the non-Hermitian skin effect has been leveraged to delocalize the wavefunctions of TMs from the boundary and thus to increase the capacity of TMs dramatically. Here, we explore the capability of nonlinearity in designing and reconfiguring the wavefunctions of TMs. With growing intensity, wavefunctions of these in-gap nonlinear TMs undergo an initial deviation from exponential decay, gradually merge into arbitrarily designable plateaus, then encompass the entire nonlinear domain, and eventually concentrate at the nonlinear boundary. Intriguingly, such extended nonlinear TMs are still robust against defects and disorders, and stable in dynamics under external excitation. Advancing the conceptual understanding of the nonlinear TMs, our results open new avenues for increasing the capacity of TMs and developing compact and reconfigurable topological devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07224v1-abstract-full').style.display = 'none'; document.getElementById('2402.07224v1-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 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 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">3 figures in the main text</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.17526">arXiv:2401.17526</a> <span> [<a href="https://arxiv.org/pdf/2401.17526">pdf</a>, <a href="https://arxiv.org/format/2401.17526">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"> Power Characterization of Noisy Quantum Kernels </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yabo Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Qi%2C+B">Bo Qi</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tongliang Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+D">Daoyi Dong</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.17526v1-abstract-short" style="display: inline;"> Quantum kernel methods have been widely recognized as one of promising quantum machine learning algorithms that have potential to achieve quantum advantages. In this paper, we theoretically characterize the power of noisy quantum kernels and demonstrate that under global depolarization noise, for different input data the predictions of the optimal hypothesis inferred by the noisy quantum kernel ap… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.17526v1-abstract-full').style.display = 'inline'; document.getElementById('2401.17526v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.17526v1-abstract-full" style="display: none;"> Quantum kernel methods have been widely recognized as one of promising quantum machine learning algorithms that have potential to achieve quantum advantages. In this paper, we theoretically characterize the power of noisy quantum kernels and demonstrate that under global depolarization noise, for different input data the predictions of the optimal hypothesis inferred by the noisy quantum kernel approximately concentrate towards some fixed value. In particular, we depict the convergence rate in terms of the strength of quantum noise, the size of training samples, the number of qubits, the number of layers affected by quantum noises, as well as the number of measurement shots. Our results show that noises may make quantum kernel methods to only have poor prediction capability, even when the generalization error is small. Thus, we provide a crucial warning to employ noisy quantum kernel methods for quantum computation and the theoretical results can also serve as guidelines when developing practical quantum kernel algorithms for achieving quantum advantages. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.17526v1-abstract-full').style.display = 'none'; document.getElementById('2401.17526v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">3 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.11098">arXiv:2401.11098</a> <span> [<a href="https://arxiv.org/pdf/2401.11098">pdf</a>, <a href="https://arxiv.org/format/2401.11098">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> </div> </div> <p class="title is-5 mathjax"> Neural auto-designer for enhanced quantum kernels </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Lei%2C+C">Cong Lei</a>, <a href="/search/quant-ph?searchtype=author&query=Du%2C+Y">Yuxuan Du</a>, <a href="/search/quant-ph?searchtype=author&query=Mi%2C+P">Peng Mi</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+J">Jun Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tongliang Liu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.11098v1-abstract-short" style="display: inline;"> Quantum kernels hold great promise for offering computational advantages over classical learners, with the effectiveness of these kernels closely tied to the design of the quantum feature map. However, the challenge of designing effective quantum feature maps for real-world datasets, particularly in the absence of sufficient prior information, remains a significant obstacle. In this study, we pres… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.11098v1-abstract-full').style.display = 'inline'; document.getElementById('2401.11098v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.11098v1-abstract-full" style="display: none;"> Quantum kernels hold great promise for offering computational advantages over classical learners, with the effectiveness of these kernels closely tied to the design of the quantum feature map. However, the challenge of designing effective quantum feature maps for real-world datasets, particularly in the absence of sufficient prior information, remains a significant obstacle. In this study, we present a data-driven approach that automates the design of problem-specific quantum feature maps. Our approach leverages feature-selection techniques to handle high-dimensional data on near-term quantum machines with limited qubits, and incorporates a deep neural predictor to efficiently evaluate the performance of various candidate quantum kernels. Through extensive numerical simulations on different datasets, we demonstrate the superiority of our proposal over prior methods, especially for the capability of eliminating the kernel concentration issue and identifying the feature map with prediction advantages. Our work not only unlocks the potential of quantum kernels for enhancing real-world tasks but also highlights the substantial role of deep learning in advancing quantum machine learning. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.11098v1-abstract-full').style.display = 'none'; document.getElementById('2401.11098v1-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">24 pages, 14 figures, 9 tables, ICLR2024</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.02714">arXiv:2401.02714</a> <span> [<a href="https://arxiv.org/pdf/2401.02714">pdf</a>, <a href="https://arxiv.org/format/2401.02714">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"> Long-Range Four-body Interactions in Structured Nonlinear Photonic Waveguides </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+J">Jia-Qi Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Miranowicz%2C+A">Adam Miranowicz</a>, <a href="/search/quant-ph?searchtype=author&query=Nori%2C+F">Franco Nori</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.02714v1-abstract-short" style="display: inline;"> Multi-photon dynamics beyond linear optical materials are of significant fundamental and technological importance in quantum information processing. However, it remains largely unexplored in nonlinear waveguide QED. In this work, we theoretically propose a structured nonlinear waveguide in the presence of staggered photon-photon interactions, which supports two branches of gaped bands for doublons… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.02714v1-abstract-full').style.display = 'inline'; document.getElementById('2401.02714v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.02714v1-abstract-full" style="display: none;"> Multi-photon dynamics beyond linear optical materials are of significant fundamental and technological importance in quantum information processing. However, it remains largely unexplored in nonlinear waveguide QED. In this work, we theoretically propose a structured nonlinear waveguide in the presence of staggered photon-photon interactions, which supports two branches of gaped bands for doublons (i.e., spatially bound-photon-pair states). In contrast to linear waveguide QED systems, we identify two important contributions to its dynamical evolution, i.e., single-photon bound states (SPBSs) and doublon bound states (DBSs). Most remarkably, the nonlinear waveguide can mediate the long-range four-body interactions between two emitter pairs, even in the presence of disturbance from SPBS. By appropriately designing system's parameters, we can achieve high-fidelity four-body Rabi oscillations mediated only by virtual doublons in DBSs. Our findings pave the way for applying structured nonlinear waveguide QED in multi-body quantum information processing and quantum simulations among remote sites. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.02714v1-abstract-full').style.display = 'none'; document.getElementById('2401.02714v1-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages; 9 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.01530">arXiv:2401.01530</a> <span> [<a href="https://arxiv.org/pdf/2401.01530">pdf</a>, <a href="https://arxiv.org/format/2401.01530">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"> Disorder-induced topological pumping on a superconducting quantum processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yu Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yu-Ran Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+Y">Yun-Hao Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+C">Congwei Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yong-Yi Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hao Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tian-Ming Li</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+C">Cheng-Lin Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Zhou%2C+S">Si-Yun Zhou</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Jia-Chi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+G">Gui-Han Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Mei%2C+Z">Zheng-Yang Mei</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+W">Wei-Guo Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+H">Hao-Tian Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Z">Zheng-He Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+C">Chi-Tong Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+K">Kaixuan Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+X">Xiaohui Song</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+S">SP Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Tian%2C+Y">Ye Tian</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+Z">Zhongcheng Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+D">Dongning Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Nori%2C+F">Franco Nori</a> , et al. (2 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.01530v1-abstract-short" style="display: inline;"> Thouless pumping, a dynamical version of the integer quantum Hall effect, represents the quantized charge pumped during an adiabatic cyclic evolution. Here we report experimental observations of nontrivial topological pumping that is induced by disorder even during a topologically trivial pumping trajectory. With a 41-qubit superconducting quantum processor, we develop a Floquet engineering techni… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.01530v1-abstract-full').style.display = 'inline'; document.getElementById('2401.01530v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.01530v1-abstract-full" style="display: none;"> Thouless pumping, a dynamical version of the integer quantum Hall effect, represents the quantized charge pumped during an adiabatic cyclic evolution. Here we report experimental observations of nontrivial topological pumping that is induced by disorder even during a topologically trivial pumping trajectory. With a 41-qubit superconducting quantum processor, we develop a Floquet engineering technique to realize cycles of adiabatic pumping by simultaneously varying the on-site potentials and the hopping couplings. We demonstrate Thouless pumping in the presence of disorder and show its breakdown as the strength of disorder increases. Moreover, we observe two types of topological pumping that are induced by on-site potential disorder and hopping disorder, respectively. Especially, an intrinsic topological pump that is induced by quasi-periodic hopping disorder has never been experimentally realized before. Our highly controllable system provides a valuable quantum simulating platform for studying various aspects of topological physics in the presence of disorder. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.01530v1-abstract-full').style.display = 'none'; document.getElementById('2401.01530v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.12362">arXiv:2311.12362</a> <span> [<a href="https://arxiv.org/pdf/2311.12362">pdf</a>, <a href="https://arxiv.org/ps/2311.12362">ps</a>, <a href="https://arxiv.org/format/2311.12362">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</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"> Genuinely accessible and inaccessible entanglement in Schwarzschild black hole </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wu%2C+S">Shu-Min Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Teng%2C+X">Xiao-Wei Teng</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+J">Jin-Xuan Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Si-Han Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong-Hua Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jie-Ci 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="2311.12362v1-abstract-short" style="display: inline;"> The genuine entanglement of Dirac fields for an N-partite system is investigated in Schwarzschild spacetime and the analysis is carried out using the single-mode approximation. Due to the Hawking effect, quantum entanglement is divided into two parts physically accessible and inaccessible entanglement. We obtain a general analytic expression of genuine N-partite entanglement that includes all acce… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.12362v1-abstract-full').style.display = 'inline'; document.getElementById('2311.12362v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.12362v1-abstract-full" style="display: none;"> The genuine entanglement of Dirac fields for an N-partite system is investigated in Schwarzschild spacetime and the analysis is carried out using the single-mode approximation. Due to the Hawking effect, quantum entanglement is divided into two parts physically accessible and inaccessible entanglement. We obtain a general analytic expression of genuine N-partite entanglement that includes all accessible and inaccessible entanglement in a Schwarzschild black hole. Unlike bosonic entanglement, the accessible N-partite entanglement of Dirac fields monotonically decreases to a nonzero value with the Hawking temperature. Interestingly, the inaccessible N-partite entanglement is a monotonic or non-monotonic function of the Hawking temperature, depending on the ratio between accessible and inaccessible modes, in contrast to bipartite or tripartite entanglement that is only a monotonic function of the Hawking temperature. Finally, we obtain two restrictive relationships for the quantum information of the black hole. This conclusion provides a new understanding of Hawking effect of the black hole. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.12362v1-abstract-full').style.display = 'none'; document.getElementById('2311.12362v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 1 figure</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Lett. B 848 (2024) 138334 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.06550">arXiv:2311.06550</a> <span> [<a href="https://arxiv.org/pdf/2311.06550">pdf</a>, <a href="https://arxiv.org/format/2311.06550">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Gases">cond-mat.quant-gas</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Non-Hermitian Skin Effect In Periodically-Driven Dissipative Ultracold Atoms </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Cai%2C+Z">Zhao-Fan Cai</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Z">Zhongmin Yang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2311.06550v1-abstract-short" style="display: inline;"> The non-Hermitian skin effect (NHSE), featured by the collapse of bulk-band eigenstates into the localized boundary modes of the systems, is one of most striking properties in the fields of non-Hermitian physics. Unique physical phenomena related to the NHSE have attracted a lot of interest, however, their experimental realizations usually require nonreciprocal hopping, which faces a great challen… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.06550v1-abstract-full').style.display = 'inline'; document.getElementById('2311.06550v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.06550v1-abstract-full" style="display: none;"> The non-Hermitian skin effect (NHSE), featured by the collapse of bulk-band eigenstates into the localized boundary modes of the systems, is one of most striking properties in the fields of non-Hermitian physics. Unique physical phenomena related to the NHSE have attracted a lot of interest, however, their experimental realizations usually require nonreciprocal hopping, which faces a great challenge in ultracold-atom systems. In this work, we propose to realize the NHSE in a 1D optical lattice by periodically-driven ultracold atoms in the presence of staggered atomic loss. By studying the effective Floquet Hamiltonian in the high-frequency approximation, we reveal the underlying mechanism for the periodic-driving-induced the NHSE. We found that the robust NHSE can be tuned by driving phase, which is manifested by the dynamical localization. Most remarkably, we uncover the periodic-driving-induced critical skin effect for two coupled chains with different driving phases, accompanied by the appearance of size-dependent topological in-gap modes. Our studies provide a feasible way for observing the NHSE and exploring corresponding unique physical phenomena due to the interplay of non-Hermiticity and many-body statistics in ultracold-atom systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.06550v1-abstract-full').style.display = 'none'; document.getElementById('2311.06550v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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, 9 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2311.03408">arXiv:2311.03408</a> <span> [<a href="https://arxiv.org/pdf/2311.03408">pdf</a>, <a href="https://arxiv.org/format/2311.03408">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Artificial Intelligence">cs.AI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Neural and Evolutionary Computing">cs.NE</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"> Training Multi-layer Neural Networks on Ising Machine </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Song%2C+X">Xujie Song</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S+E">Shengbo Eben Li</a>, <a href="/search/quant-ph?searchtype=author&query=Duan%2C+J">Jingliang Duan</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+W">Wenxuan Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+K">Keqiang Li</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2311.03408v1-abstract-short" style="display: inline;"> As a dedicated quantum device, Ising machines could solve large-scale binary optimization problems in milliseconds. There is emerging interest in utilizing Ising machines to train feedforward neural networks due to the prosperity of generative artificial intelligence. However, existing methods can only train single-layer feedforward networks because of the complex nonlinear network topology. This… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.03408v1-abstract-full').style.display = 'inline'; document.getElementById('2311.03408v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2311.03408v1-abstract-full" style="display: none;"> As a dedicated quantum device, Ising machines could solve large-scale binary optimization problems in milliseconds. There is emerging interest in utilizing Ising machines to train feedforward neural networks due to the prosperity of generative artificial intelligence. However, existing methods can only train single-layer feedforward networks because of the complex nonlinear network topology. This paper proposes an Ising learning algorithm to train quantized neural network (QNN), by incorporating two essential techinques, namely binary representation of topological network and order reduction of loss function. As far as we know, this is the first algorithm to train multi-layer feedforward networks on Ising machines, providing an alternative to gradient-based backpropagation. Firstly, training QNN is formulated as a quadratic constrained binary optimization (QCBO) problem by representing neuron connection and activation function as equality constraints. All quantized variables are encoded by binary bits based on binary encoding protocol. Secondly, QCBO is converted to a quadratic unconstrained binary optimization (QUBO) problem, that can be efficiently solved on Ising machines. The conversion leverages both penalty function and Rosenberg order reduction, who together eliminate equality constraints and reduce high-order loss function into a quadratic one. With some assumptions, theoretical analysis shows the space complexity of our algorithm is $\mathcal{O}(H^2L + HLN\log H)$, quantifying the required number of Ising spins. Finally, the algorithm effectiveness is validated with a simulated Ising machine on MNIST dataset. After annealing 700 ms, the classification accuracy achieves 98.3%. Among 100 runs, the success probability of finding the optimal solution is 72%. Along with the increasing number of spins on Ising machine, our algorithm has the potential to train deeper neural networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2311.03408v1-abstract-full').style.display = 'none'; document.getElementById('2311.03408v1-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 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.16152">arXiv:2309.16152</a> <span> [<a href="https://arxiv.org/pdf/2309.16152">pdf</a>, <a href="https://arxiv.org/format/2309.16152">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevB.109.L041102">10.1103/PhysRevB.109.L041102 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Braiding topology of symmetry-protected degeneracy points in non-Hermitian systems </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+J">Jia-Zheng Li</a>, <a href="/search/quant-ph?searchtype=author&query=Bai%2C+K">Kai Bai</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+C">Cheng Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tian-Rui Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Fang%2C+L">Liang Fang</a>, <a href="/search/quant-ph?searchtype=author&query=Wan%2C+D">Duanduan Wan</a>, <a href="/search/quant-ph?searchtype=author&query=Xiao%2C+M">Meng Xiao</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="2309.16152v2-abstract-short" style="display: inline;"> Degeneracy points in non-Hermitian systems are of great interest. While a homotopic framework exists for understanding their behavior in the absence of symmetry, it does not apply to symmetry-protected degeneracy points with reduced codimension. In this work, utilizing algebraic topology, we provide a systematic classification of these symmetry-protected degenerate points and investigate the braid… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.16152v2-abstract-full').style.display = 'inline'; document.getElementById('2309.16152v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.16152v2-abstract-full" style="display: none;"> Degeneracy points in non-Hermitian systems are of great interest. While a homotopic framework exists for understanding their behavior in the absence of symmetry, it does not apply to symmetry-protected degeneracy points with reduced codimension. In this work, utilizing algebraic topology, we provide a systematic classification of these symmetry-protected degenerate points and investigate the braid conservation rule followed by them. Using a model Hamiltonian and circuit simulation, we discover that, contrary to simple annihilation, pairwise-created symmetry-protected degeneracy points merge into a higher-order degeneracy point, which goes beyond the abelian picture. Our findings empower researchers across diverse fields to uncover new phenomena and applications harnessing symmetry-protected non-Hermitian degeneracy points. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.16152v2-abstract-full').style.display = 'none'; document.getElementById('2309.16152v2-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 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 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. B 109 (2024) L041102 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.16000">arXiv:2309.16000</a> <span> [<a href="https://arxiv.org/pdf/2309.16000">pdf</a>, <a href="https://arxiv.org/format/2309.16000">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Experiment">hep-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</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"> Universal determination of comagnetometer response to spin couplings </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Padniuk%2C+M">Mikhail Padniuk</a>, <a href="/search/quant-ph?searchtype=author&query=Klinger%2C+E">Emmanuel Klinger</a>, <a href="/search/quant-ph?searchtype=author&query=Lukasiewicz%2C+G">Grzegorz Lukasiewicz</a>, <a href="/search/quant-ph?searchtype=author&query=Gavilan-Martin%2C+D">Daniel Gavilan-Martin</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tianhao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Pustelny%2C+S">Szymon Pustelny</a>, <a href="/search/quant-ph?searchtype=author&query=Kimball%2C+D+F+J">Derek F. Jackson Kimball</a>, <a href="/search/quant-ph?searchtype=author&query=Budker%2C+D">Dmitry Budker</a>, <a href="/search/quant-ph?searchtype=author&query=Wickenbrock%2C+A">Arne Wickenbrock</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="2309.16000v2-abstract-short" style="display: inline;"> We propose and demonstrate a general method to calibrate the frequency-dependent response of self-compensating noble-gas-alkali-metal comagnetometers to arbitrary spin perturbations. This includes magnetic and nonmagnetic perturbations like rotations and exotic spin interactions. The method is based on a fit of the magnetic field response to an analytical model. The frequency-dependent response of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.16000v2-abstract-full').style.display = 'inline'; document.getElementById('2309.16000v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.16000v2-abstract-full" style="display: none;"> We propose and demonstrate a general method to calibrate the frequency-dependent response of self-compensating noble-gas-alkali-metal comagnetometers to arbitrary spin perturbations. This includes magnetic and nonmagnetic perturbations like rotations and exotic spin interactions. The method is based on a fit of the magnetic field response to an analytical model. The frequency-dependent response of the comagnetometer to arbitrary spin perturbations can be inferred using the fit parameters. We demonstrate the effectiveness of this method by comparing the inferred rotation response to an experimental measurement of the rotation response. Our results show that experiments relying on zero-frequency calibration of the comagnetometer response can over- or under-estimate the comagnetometer sensitivity by orders of magnitude over a wide frequency range. Moreover, this discrepancy accumulates over time as operational parameters tend to drift during comagnetometer operation. The demonstrated calibration protocol enables accurate prediction and control of comagnetometer sensitivity to, for example, ultralight bosonic dark-matter fields coupling to electron or nuclear spins as well as accurate monitoring and control of the relevant system parameters. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.16000v2-abstract-full').style.display = 'none'; document.getElementById('2309.16000v2-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 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.09418">arXiv:2309.09418</a> <span> [<a href="https://arxiv.org/pdf/2309.09418">pdf</a>, <a href="https://arxiv.org/format/2309.09418">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="Mathematical Physics">math-ph</span> </div> </div> <p class="title is-5 mathjax"> Real eigenvalues are determined by the recursion of eigenstates </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Youguo 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="2309.09418v1-abstract-short" style="display: inline;"> Quantum physics is generally concerned with real eigenvalues due to the unitarity of time evolution. With the introduction of $\mathcal{PT}$ symmetry, a widely accepted consensus is that, even if the Hamiltonian of the system is not Hermitian, the eigenvalues can still be pure real under specific symmetry. Hence, great enthusiasm has been devoted to exploring the eigenvalue problem of non-Hermitia… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.09418v1-abstract-full').style.display = 'inline'; document.getElementById('2309.09418v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.09418v1-abstract-full" style="display: none;"> Quantum physics is generally concerned with real eigenvalues due to the unitarity of time evolution. With the introduction of $\mathcal{PT}$ symmetry, a widely accepted consensus is that, even if the Hamiltonian of the system is not Hermitian, the eigenvalues can still be pure real under specific symmetry. Hence, great enthusiasm has been devoted to exploring the eigenvalue problem of non-Hermitian systems. In this work, from a distinct perspective, we demonstrate that real eigenvalues can also emerge under the appropriate recursive condition of eigenstates. Consequently, our findings provide another path to extract the real energy spectrum of non-Hermitian systems, which guarantees the conservation of probability and stimulates future experimental observations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.09418v1-abstract-full').style.display = 'none'; document.getElementById('2309.09418v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.06713">arXiv:2309.06713</a> <span> [<a href="https://arxiv.org/pdf/2309.06713">pdf</a>, <a href="https://arxiv.org/format/2309.06713">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.109.042205">10.1103/PhysRevA.109.042205 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental demonstration of enhanced violations of Leggett-Garg inequalities in a $\mathcal{PT}$-symmetric trapped-ion qubit </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Lu%2C+P">Pengfei Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Rao%2C+X">Xinxin Rao</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Teng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yang Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Bian%2C+J">Ji Bian</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+F">Feng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Luo%2C+L">Le Luo</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.06713v1-abstract-short" style="display: inline;"> The Leggett-Garg inequality (LGI) places a bound for the distinction between quantum systems and classical systems. Despite that the tests of temporal quantum correlations on LGIs have been studied in Hermitian realm, there are still unknowns for LGIs in non-Hermitian conditions due to the interplay between dissipation and coherence. For example, a theoretical hypothesis to be experimentally valid… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.06713v1-abstract-full').style.display = 'inline'; document.getElementById('2309.06713v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.06713v1-abstract-full" style="display: none;"> The Leggett-Garg inequality (LGI) places a bound for the distinction between quantum systems and classical systems. Despite that the tests of temporal quantum correlations on LGIs have been studied in Hermitian realm, there are still unknowns for LGIs in non-Hermitian conditions due to the interplay between dissipation and coherence. For example, a theoretical hypothesis to be experimentally validated, suggests that within non-Hermitian systems, the non-unitary evolution of the system dynamics allows the boundaries of the LGIs to surpass the constraints imposed by traditional quantum mechanics. Here, we demonstrate the experimental violation of LGIs in a parity-time ($\mathcal{PT}$)-symmetric trapped-ion qubit system by measuring the temporal correlation of the evolving states at different times. We find that the upper bounds of the three-time parameter $K_3$ and the four-time parameter $K_4$ show enhanced violations with the increasing dissipation, and can reach the upper limit by infinitely approaching exceptional point. We also observe the distinct behavior of the lower bounds for $K_3$ and $K_4$. While the lower bound for $K_3$ remains constant, the case for $K_4$ shows an upward trend with increasing dissipation. These results reveal a pronounced dependence of the system's temporal quantum correlations on its dissipation to the environment. This opens up a potential pathway for harnessing dissipation to modulate quantum correlations and entanglement. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.06713v1-abstract-full').style.display = 'none'; document.getElementById('2309.06713v1-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 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> Physical Review A 109, 042205 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.13235">arXiv:2308.13235</a> <span> [<a href="https://arxiv.org/pdf/2308.13235">pdf</a>, <a href="https://arxiv.org/format/2308.13235">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 multiple steady states with engineered dissipation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Li%2C+L">Li Li</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Guo%2C+X">Xue-Yi Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+H">He Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+S">Silu Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+Z">Zhongcheng Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+X">Xiaohui Song</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yu-Xiang Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+K">Kai Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+H">Heng Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+D">Dongning 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="2308.13235v1-abstract-short" style="display: inline;"> Simulating the dynamics of open quantum systems is essential in achieving practical quantum computation and understanding novel nonequilibrium behaviors. However, quantum simulation of a many-body system coupled to an engineered reservoir has yet to be fully explored in present-day experiment platforms. In this work, we introduce engineered noise into a one-dimensional ten-qubit superconducting qu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.13235v1-abstract-full').style.display = 'inline'; document.getElementById('2308.13235v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.13235v1-abstract-full" style="display: none;"> Simulating the dynamics of open quantum systems is essential in achieving practical quantum computation and understanding novel nonequilibrium behaviors. However, quantum simulation of a many-body system coupled to an engineered reservoir has yet to be fully explored in present-day experiment platforms. In this work, we introduce engineered noise into a one-dimensional ten-qubit superconducting quantum processor to emulate a generic many-body open quantum system. Our approach originates from the stochastic unravellings of the master equation. By measuring the end-to-end correlation, we identify multiple steady states stemmed from a strong symmetry, which is established on the modified Hamiltonian via Floquet engineering. Furthermore, we find that the information saved in the initial state maintains in the steady state driven by the continuous dissipation on a five-qubit chain. Our work provides a manageable and hardware-efficient strategy for the open-system quantum simulation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.13235v1-abstract-full').style.display = 'none'; document.getElementById('2308.13235v1-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 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.11290">arXiv:2308.11290</a> <span> [<a href="https://arxiv.org/pdf/2308.11290">pdf</a>, <a href="https://arxiv.org/format/2308.11290">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Artificial Intelligence">cs.AI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</span> </div> </div> <p class="title is-5 mathjax"> ShadowNet for Data-Centric Quantum System Learning </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Du%2C+Y">Yuxuan Du</a>, <a href="/search/quant-ph?searchtype=author&query=Yang%2C+Y">Yibo Yang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tongliang Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Lin%2C+Z">Zhouchen Lin</a>, <a href="/search/quant-ph?searchtype=author&query=Ghanem%2C+B">Bernard Ghanem</a>, <a href="/search/quant-ph?searchtype=author&query=Tao%2C+D">Dacheng Tao</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.11290v1-abstract-short" style="display: inline;"> Understanding the dynamics of large quantum systems is hindered by the curse of dimensionality. Statistical learning offers new possibilities in this regime by neural-network protocols and classical shadows, while both methods have limitations: the former is plagued by the predictive uncertainty and the latter lacks the generalization ability. Here we propose a data-centric learning paradigm combi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.11290v1-abstract-full').style.display = 'inline'; document.getElementById('2308.11290v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.11290v1-abstract-full" style="display: none;"> Understanding the dynamics of large quantum systems is hindered by the curse of dimensionality. Statistical learning offers new possibilities in this regime by neural-network protocols and classical shadows, while both methods have limitations: the former is plagued by the predictive uncertainty and the latter lacks the generalization ability. Here we propose a data-centric learning paradigm combining the strength of these two approaches to facilitate diverse quantum system learning (QSL) tasks. Particularly, our paradigm utilizes classical shadows along with other easily obtainable information of quantum systems to create the training dataset, which is then learnt by neural networks to unveil the underlying mapping rule of the explored QSL problem. Capitalizing on the generalization power of neural networks, this paradigm can be trained offline and excel at predicting previously unseen systems at the inference stage, even with few state copies. Besides, it inherits the characteristic of classical shadows, enabling memory-efficient storage and faithful prediction. These features underscore the immense potential of the proposed data-centric approach in discovering novel and large-scale quantum systems. For concreteness, we present the instantiation of our paradigm in quantum state tomography and direct fidelity estimation tasks and conduct numerical analysis up to 60 qubits. Our work showcases the profound prospects of data-centric artificial intelligence to advance QSL in a faithful and generalizable manner. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.11290v1-abstract-full').style.display = 'none'; document.getElementById('2308.11290v1-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 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.11916">arXiv:2307.11916</a> <span> [<a href="https://arxiv.org/pdf/2307.11916">pdf</a>, <a href="https://arxiv.org/format/2307.11916">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Microwave-based quantum control and coherence protection of tin-vacancy spin qubits in a strain-tuned diamond membrane heterostructure </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Guo%2C+X">Xinghan Guo</a>, <a href="/search/quant-ph?searchtype=author&query=Stramma%2C+A+M">Alexander M. Stramma</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Z">Zixi Li</a>, <a href="/search/quant-ph?searchtype=author&query=Roth%2C+W+G">William G. Roth</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+B">Benchen Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Jin%2C+Y">Yu Jin</a>, <a href="/search/quant-ph?searchtype=author&query=Parker%2C+R+A">Ryan A. Parker</a>, <a href="/search/quant-ph?searchtype=author&query=Mart%C3%ADnez%2C+J+A">Jes煤s Arjona Mart铆nez</a>, <a href="/search/quant-ph?searchtype=author&query=Shofer%2C+N">Noah Shofer</a>, <a href="/search/quant-ph?searchtype=author&query=Michaels%2C+C+P">Cathryn P. Michaels</a>, <a href="/search/quant-ph?searchtype=author&query=Purser%2C+C+P">Carola P. Purser</a>, <a href="/search/quant-ph?searchtype=author&query=Appel%2C+M+H">Martin H. Appel</a>, <a href="/search/quant-ph?searchtype=author&query=Alexeev%2C+E+M">Evgeny M. Alexeev</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tianle Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Ferrari%2C+A+C">Andrea C. Ferrari</a>, <a href="/search/quant-ph?searchtype=author&query=Awschalom%2C+D+D">David D. Awschalom</a>, <a href="/search/quant-ph?searchtype=author&query=Delegan%2C+N">Nazar Delegan</a>, <a href="/search/quant-ph?searchtype=author&query=Pingault%2C+B">Benjamin Pingault</a>, <a href="/search/quant-ph?searchtype=author&query=Galli%2C+G">Giulia Galli</a>, <a href="/search/quant-ph?searchtype=author&query=Heremans%2C+F+J">F. Joseph Heremans</a>, <a href="/search/quant-ph?searchtype=author&query=Atat%C3%BCre%2C+M">Mete Atat眉re</a>, <a href="/search/quant-ph?searchtype=author&query=High%2C+A+A">Alexander A. High</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="2307.11916v2-abstract-short" style="display: inline;"> Robust spin-photon interfaces in solids are essential components in quantum networking and sensing technologies. Ideally, these interfaces combine a long-lived spin memory, coherent optical transitions, fast and high-fidelity spin manipulation, and straightforward device integration and scaling. The tin-vacancy center (SnV) in diamond is a promising spin-photon interface with desirable optical and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.11916v2-abstract-full').style.display = 'inline'; document.getElementById('2307.11916v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.11916v2-abstract-full" style="display: none;"> Robust spin-photon interfaces in solids are essential components in quantum networking and sensing technologies. Ideally, these interfaces combine a long-lived spin memory, coherent optical transitions, fast and high-fidelity spin manipulation, and straightforward device integration and scaling. The tin-vacancy center (SnV) in diamond is a promising spin-photon interface with desirable optical and spin properties at 1.7 K. However, the SnV spin lacks efficient microwave control and its spin coherence degrades with higher temperature. In this work, we introduce a new platform that overcomes these challenges - SnV centers in uniformly strained thin diamond membranes. The controlled generation of crystal strain introduces orbital mixing that allows microwave control of the spin state with 99.36(9) % gate fidelity and spin coherence protection beyond a millisecond. Moreover, the presence of crystal strain suppresses temperature dependent dephasing processes, leading to a considerable improvement of the coherence time up to 223(10) $渭$s at 4 K, a widely accessible temperature in common cryogenic systems. Critically, the coherence of optical transitions is unaffected by the elevated temperature, exhibiting nearly lifetime-limited optical linewidths. Combined with the compatibility of diamond membranes with device integration, the demonstrated platform is an ideal spin-photon interface for future quantum technologies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.11916v2-abstract-full').style.display = 'none'; document.getElementById('2307.11916v2-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 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.05312">arXiv:2306.05312</a> <span> [<a href="https://arxiv.org/pdf/2306.05312">pdf</a>, <a href="https://arxiv.org/format/2306.05312">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.20.044028">10.1103/PhysRevApplied.20.044028 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Tunable Coupling Architectures with Capacitively Connecting Pads for Large-Scale Superconducting Multi-Qubit Processors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liang%2C+G">Gui-Han Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+X">Xiao-Hui Song</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+C">Cheng-Lin Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Gu%2C+X">Xu-Yang Gu</a>, <a href="/search/quant-ph?searchtype=author&query=Yan%2C+Y">Yu Yan</a>, <a href="/search/quant-ph?searchtype=author&query=Mei%2C+Z">Zheng-Yang Mei</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+S">Si-Lu Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Bu%2C+Y">Yi-Zhou Bu</a>, <a href="/search/quant-ph?searchtype=author&query=Xiao%2C+Y">Yong-Xi Xiao</a>, <a href="/search/quant-ph?searchtype=author&query=Yu%2C+Y">Yi-Han Yu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+M">Ming-Chuan Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+Y">Yun-Hao Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+H">He Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xiang Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+L">Li Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+J">Jing-Zhe Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Tian%2C+Y">Ye Tian</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+S">Shi-Ping Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+K">Kai Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+H">Heng Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+Z">Zhong-Cheng Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+D">Dong-Ning 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="2306.05312v1-abstract-short" style="display: inline;"> We have proposed and experimentally verified a tunable inter-qubit coupling scheme for large-scale integration of superconducting qubits. The key feature of the scheme is the insertion of connecting pads between qubit and tunable coupling element. In such a way, the distance between two qubits can be increased considerably to a few millimeters, leaving enough space for arranging control lines, rea… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.05312v1-abstract-full').style.display = 'inline'; document.getElementById('2306.05312v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.05312v1-abstract-full" style="display: none;"> We have proposed and experimentally verified a tunable inter-qubit coupling scheme for large-scale integration of superconducting qubits. The key feature of the scheme is the insertion of connecting pads between qubit and tunable coupling element. In such a way, the distance between two qubits can be increased considerably to a few millimeters, leaving enough space for arranging control lines, readout resonators and other necessary structures. The increased inter-qubit distance provides more wiring space for flip-chip process and reduces crosstalk between qubits and from control lines to qubits. We use the term Tunable Coupler with Capacitively Connecting Pad (TCCP) to name the tunable coupling part that consists of a transmon coupler and capacitively connecting pads. With the different placement of connecting pads, different TCCP architectures can be realized. We have designed and fabricated a few multi-qubit devices in which TCCP is used for coupling. The measured results show that the performance of the qubits coupled by the TCCP, such as $T_1$ and $T_2$, was similar to that of the traditional transmon qubits without TCCP. Meanwhile, our TCCP also exhibited a wide tunable range of the effective coupling strength and a low residual ZZ interaction between the qubits by properly tuning the parameters on the design. Finally, we successfully implemented an adiabatic CZ gate with TCCP. Furthermore, by introducing TCCP, we also discuss the realization of the flip-chip process and tunable coupling qubits between different chips. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.05312v1-abstract-full').style.display = 'none'; document.getElementById('2306.05312v1-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 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Main text: 7 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, 044028 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.09152">arXiv:2305.09152</a> <span> [<a href="https://arxiv.org/pdf/2305.09152">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link 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="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Security Enhancement of Quantum Noise Stream Cipher Based on Probabilistic Constellation Shaping </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+S">Sheng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wei%2C+S">Shuang Wei</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+W">Wei Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Lei%2C+C">Chao Lei</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tianhe Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yajie Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+Y">Yunbo Li</a>, <a href="/search/quant-ph?searchtype=author&query=Ge%2C+D">Dawei Ge</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+D">Dong Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+Y">Yongli Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+D">Dechao Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Han Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Jie 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="2305.09152v1-abstract-short" style="display: inline;"> We propose a QNSC pre-coding scheme based on probabilistic shaping of the basis, to reduce the probability of ciphertext bits that are easier to be intercepted. Experiment results show this scheme can improve the security performance by 100% in terms of Eve's cipher text BER. </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.09152v1-abstract-full" style="display: none;"> We propose a QNSC pre-coding scheme based on probabilistic shaping of the basis, to reduce the probability of ciphertext bits that are easier to be intercepted. Experiment results show this scheme can improve the security performance by 100% in terms of Eve's cipher text BER. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.09152v1-abstract-full').style.display = 'none'; document.getElementById('2305.09152v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.01897">arXiv:2305.01897</a> <span> [<a href="https://arxiv.org/pdf/2305.01897">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Quantum two-way time transfer over a 103 km urban fiber </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Hong%2C+H">Huibo Hong</a>, <a href="/search/quant-ph?searchtype=author&query=Quan%2C+R">Runai Quan</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+X">Xiao Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yuting Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+M">Mingtao Cao</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+R">Ruifang Dong</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+S">Shougang 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="2305.01897v2-abstract-short" style="display: inline;"> As a new approach to realizing high-precision time synchronization between remote time scales, quantum two-way time transfer via laboratory fiber link has shown significant enhancement of the transfer stability to several tens of femtoseconds. To verify its great potential in practical systems, the field test in long-haul installed fiber optic infrastructure is required to be demonstrated. In this… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.01897v2-abstract-full').style.display = 'inline'; document.getElementById('2305.01897v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.01897v2-abstract-full" style="display: none;"> As a new approach to realizing high-precision time synchronization between remote time scales, quantum two-way time transfer via laboratory fiber link has shown significant enhancement of the transfer stability to several tens of femtoseconds. To verify its great potential in practical systems, the field test in long-haul installed fiber optic infrastructure is required to be demonstrated. In this paper, we implement the two-way quantum time transfer over a 103 km urban fiber link. A time transfer stability of 3.67 ps at 10 s and 0.28 ps at 40000 s has been achieved, despite the large attenuation of 38 dB leading to fewer than 40 correlated events per second. This achievement marks the first successful step of quantum two-way time transfer in the task of high-precision long-distance field transfer systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.01897v2-abstract-full').style.display = 'none'; document.getElementById('2305.01897v2-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.10710">arXiv:2304.10710</a> <span> [<a href="https://arxiv.org/pdf/2304.10710">pdf</a>, <a href="https://arxiv.org/format/2304.10710">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"> Realizing quantum optics in structured environments with giant atoms </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+X">Xin Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+H">Huai-Bing Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Nori%2C+F">Franco Nori</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="2304.10710v1-abstract-short" style="display: inline;"> To go beyond quantum optics in free-space setups, atom-light interfaces with structured photonic environments are often employed to realize unconventional quantum electrodynamics (QED) phenomena. However, when employed as quantum buses, those long-distance nanostructures are limited by fabrication disorders. In this work, we alternatively propose to realize structured lightmatter interactions by e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.10710v1-abstract-full').style.display = 'inline'; document.getElementById('2304.10710v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.10710v1-abstract-full" style="display: none;"> To go beyond quantum optics in free-space setups, atom-light interfaces with structured photonic environments are often employed to realize unconventional quantum electrodynamics (QED) phenomena. However, when employed as quantum buses, those long-distance nanostructures are limited by fabrication disorders. In this work, we alternatively propose to realize structured lightmatter interactions by engineering multiple coupling points of hybrid giant atom-conventionalenvironments without any periodic structure. We present a generic optimization method to obtain the real-space coupling sequence for multiple coupling points. We report a broadband chiral emission in a very wide frequency regime, with no analog in other quantum setups. Moreover, we show that the QED phenomena in the band gap environment, such as fractional atomic decay and dipole-dipole interactions mediated by a bound state, can be observed in our setup. Numerical results indicate that our proposal is robust against fabrication disorders of the coupling sequence. Our work opens up a new route for realizing unconventional light-matter interactions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.10710v1-abstract-full').style.display = 'none'; document.getElementById('2304.10710v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 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">19 papges, 12 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.08296">arXiv:2304.08296</a> <span> [<a href="https://arxiv.org/pdf/2304.08296">pdf</a>, <a href="https://arxiv.org/ps/2304.08296">ps</a>, <a href="https://arxiv.org/format/2304.08296">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"> Modes mismatch induced variation of quantum coherence for two-mode localized Gaussian states in accelerated frame </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Gong%2C+X">Xiaolong Gong</a>, <a href="/search/quant-ph?searchtype=author&query=Fang%2C+Y">Yue Fang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tonghua Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Cao%2C+S">Shuo Cao</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="2304.08296v1-abstract-short" style="display: inline;"> Quantum coherence is the basic concept of superposition of quantum states and plays an important role in quantum metrology. We show how a pair of uniformly accelerated observers with a local two-mode Gaussian quantum state affects the Gaussian quantum coherence. We find that the quantum coherence decreases with increasing acceleration, which is due to the Unruh effect that destroys the quantum res… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.08296v1-abstract-full').style.display = 'inline'; document.getElementById('2304.08296v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.08296v1-abstract-full" style="display: none;"> Quantum coherence is the basic concept of superposition of quantum states and plays an important role in quantum metrology. We show how a pair of uniformly accelerated observers with a local two-mode Gaussian quantum state affects the Gaussian quantum coherence. We find that the quantum coherence decreases with increasing acceleration, which is due to the Unruh effect that destroys the quantum resource. Essentially, the variation of quantum coherence is caused by the modes mismatch between the input and output mode. Through 2000 randomly generated states, we demonstrate that such mismatch is dominated by the acceleration effect and mildly affected by the waveform parameters. Moreover, the squeezing parameter acted as a suppressor of the reduced coherence, but it tended to be invalid in the high squeezing. In addition, the squeezing parameter can act as a suppressor of the reduced coherence, but the effect of the squeezing parameter tends to be ineffective under high squeezing conditions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.08296v1-abstract-full').style.display = 'none'; document.getElementById('2304.08296v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 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">7 pages, 5 figures, accepted for publication in The European Physical Journal Plus</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.06996">arXiv:2304.06996</a> <span> [<a href="https://arxiv.org/pdf/2304.06996">pdf</a>, <a href="https://arxiv.org/format/2304.06996">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"> Implementation of electromagnetic analogy to gravity mediated entanglement </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Bian%2C+J">Ji Bian</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Teng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Lu%2C+P">Pengfei Lu</a>, <a href="/search/quant-ph?searchtype=author&query=Lao%2C+Q">Qifeng Lao</a>, <a href="/search/quant-ph?searchtype=author&query=Rao%2C+X">Xinxin Rao</a>, <a href="/search/quant-ph?searchtype=author&query=Zhu%2C+F">Feng Zhu</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yang Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Luo%2C+L">Le Luo</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.06996v1-abstract-short" style="display: inline;"> Recently, experiments aimed at measuring gravity mediated entanglement (GME) using quantum information techniques have been proposed, based on the assumption that if two systems get entangled through local interactions with gravitational field, then this field must be quantum. While there is a debate about what could be drawn from GME, quantum simulation might provide some clarification. Here, we… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.06996v1-abstract-full').style.display = 'inline'; document.getElementById('2304.06996v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.06996v1-abstract-full" style="display: none;"> Recently, experiments aimed at measuring gravity mediated entanglement (GME) using quantum information techniques have been proposed, based on the assumption that if two systems get entangled through local interactions with gravitational field, then this field must be quantum. While there is a debate about what could be drawn from GME, quantum simulation might provide some clarification. Here, we present electromagnetic analogy of GME using magnetic-field mediated interaction between the electron and nucleus in a single atom. Our work successfully implements the general procedures of GME experiments and confirms that the mediating field does not support the mean-field description. It also clarifies that, without considering the light-crossing time, the GME experiment would not distinguish a quantum-field-theory description from a quantum-controlled classical field one. Furthermore, this work provides a novel method to construct two-qubit systems in a single atom, and providing the first quantum simulation of GME using material qubits. It helps to conceive the future GME experiments on the scale of light-crossing time. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.06996v1-abstract-full').style.display = 'none'; document.getElementById('2304.06996v1-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">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">12 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/2302.06310">arXiv:2302.06310</a> <span> [<a href="https://arxiv.org/pdf/2302.06310">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Efficient real-time spin readout of nitrogen-vacancy centers based on Bayesian estimation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Jixing Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tianzheng Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Xia%2C+S">Sigang Xia</a>, <a href="/search/quant-ph?searchtype=author&query=Bian%2C+G">Guodong Bian</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+P">Pengcheng Fan</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+M">Mingxin Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+S">Sixian Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+X">Xiangyun Li</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+C">Chen Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+S">Shaoda Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Yuan%2C+H">Heng Yuan</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="2302.06310v1-abstract-short" style="display: inline;"> In this work, to improve the spin readout efficiency of the nitrogen vacancy (NV) center, a real-time Bayesian estimation algorithm is proposed, which combines both the prior probability distribution and the fluorescence likelihood function established by the implementation of the NV center dynamics model. The theoretical surpass of the Cramer-Rao lower bound of the readout variance and the improv… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.06310v1-abstract-full').style.display = 'inline'; document.getElementById('2302.06310v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.06310v1-abstract-full" style="display: none;"> In this work, to improve the spin readout efficiency of the nitrogen vacancy (NV) center, a real-time Bayesian estimation algorithm is proposed, which combines both the prior probability distribution and the fluorescence likelihood function established by the implementation of the NV center dynamics model. The theoretical surpass of the Cramer-Rao lower bound of the readout variance and the improvement of the readout efficiency in the simulation indicate that our approach is an appealing alternative to the conventional photon summation method. The Bayesian real-time estimation readout was experimentally realized by combining a high-performance acquisition and processing hardware, and the Rabi oscillation experiments divulged that the signal-to-noise ratio of our approach was improved by 28.6%. Therefore, it is anticipated that the employed Bayesian estimation readout will effectively present superior sensing capabilities of the NV ensemble, and foster the further development of compact and scalable quantum sensors and consequently novel quantum information processing devices on a monolithic platform. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.06310v1-abstract-full').style.display = 'none'; document.getElementById('2302.06310v1-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 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.02281">arXiv:2302.02281</a> <span> [<a href="https://arxiv.org/pdf/2302.02281">pdf</a>, <a href="https://arxiv.org/format/2302.02281">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Disordered Systems and Neural Networks">cond-mat.dis-nn</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> How to predict critical state: Invariance of Lyapunov exponent in dual spaces </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Xia%2C+X">Xu Xia</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="2302.02281v2-abstract-short" style="display: inline;"> The critical state in disordered systems, a fascinating and subtle eigenstate, has attracted a lot of research interest. However, the nature of the critical state is difficult to describe quantitatively. Most of the studies focus on numerical verification, and cannot predict the system in which the critical state exists. In this work, we propose an explicit and universal criterion that for the cri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.02281v2-abstract-full').style.display = 'inline'; document.getElementById('2302.02281v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.02281v2-abstract-full" style="display: none;"> The critical state in disordered systems, a fascinating and subtle eigenstate, has attracted a lot of research interest. However, the nature of the critical state is difficult to describe quantitatively. Most of the studies focus on numerical verification, and cannot predict the system in which the critical state exists. In this work, we propose an explicit and universal criterion that for the critical state Lyapunov exponent should be 0 simultaneously in dual spaces, namely Lyapunov exponent remains invariant under Fourier transform. With this criterion, we exactly predict a specific system hosting a large number of critical states for the first time. Then, we perform numerical verification of the theoretical prediction, and display the self-similarity and scale invariance of the critical state. Finally, we conjecture that there exist some kind of connection between the invariance of the Lyapunov exponent and conformal invariance. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.02281v2-abstract-full').style.display = 'none'; document.getElementById('2302.02281v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 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</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.04092">arXiv:2301.04092</a> <span> [<a href="https://arxiv.org/pdf/2301.04092">pdf</a>, <a href="https://arxiv.org/ps/2301.04092">ps</a>, <a href="https://arxiv.org/format/2301.04092">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mathematical Physics">math-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="General Relativity and Quantum Cosmology">gr-qc</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="High Energy Physics - Theory">hep-th</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"> Exceptional points for associated Legendre functions of the second kind </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tianye Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Norman%2C+D+A">Daniel A. Norman</a>, <a href="/search/quant-ph?searchtype=author&query=Mannheim%2C+P+D">Philip D. Mannheim</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="2301.04092v1-abstract-short" style="display: inline;"> We consider the complex $谓$ plane structure of the associated Legendre function of the second kind $Q^{-1/2-K}_谓(\cosh蟻)$. We find that for any noninteger value for $K$ $Q^{-1/2-K}_谓(\cosh蟻)$ has an infinite number of poles in the complex $谓$ plane, but for any negative integer $K$ there are no poles at all. For $K=0$ or any positive integer $K$ there is only a finite number of poles, with there o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.04092v1-abstract-full').style.display = 'inline'; document.getElementById('2301.04092v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.04092v1-abstract-full" style="display: none;"> We consider the complex $谓$ plane structure of the associated Legendre function of the second kind $Q^{-1/2-K}_谓(\cosh蟻)$. We find that for any noninteger value for $K$ $Q^{-1/2-K}_谓(\cosh蟻)$ has an infinite number of poles in the complex $谓$ plane, but for any negative integer $K$ there are no poles at all. For $K=0$ or any positive integer $K$ there is only a finite number of poles, with there only being one single pole (at $谓=0$) when $K=0$. This pattern is characteristic of the exceptional points that appear in a wide variety of physical contexts. However, unusually for theories with exceptional points, $Q^{-1/2-K}_谓(\cosh蟻)$ has an infinite number of them. Other than in the $PT$-symmetry Jordan-block case, exceptional points usually occur at complex values of parameters. While not being Jordan-block exceptional points themselves, the exceptional points associated with the $Q^{-1/2-K}_谓(\cosh蟻)$ nonetheless occur at real values of $K$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.04092v1-abstract-full').style.display = 'none'; document.getElementById('2301.04092v1-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 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.01741">arXiv:2212.01741</a> <span> [<a href="https://arxiv.org/pdf/2212.01741">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> </div> </div> <p class="title is-5 mathjax"> Quantum two-way time transfer over a hybrid free-space and fiber link </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+X">Xiao Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Shi%2C+B">Bingke Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Quan%2C+R">Runai Quan</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yuting Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Xia%2C+Z">Zhiguang Xia</a>, <a href="/search/quant-ph?searchtype=author&query=Hong%2C+H">Huibo Hong</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wu%2C+J">Jincai Wu</a>, <a href="/search/quant-ph?searchtype=author&query=Qiang%2C+J">Jia Qiang</a>, <a href="/search/quant-ph?searchtype=author&query=Jia%2C+J">Jianjun Jia</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+S">Shougang Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Dong%2C+R">Ruifang Dong</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2212.01741v1-abstract-short" style="display: inline;"> As the superiority of quantum two-way time transfer (Q-TWTT) has been proved convincingly over fiber links, its implementation on free-space links becomes an urgent need for remote time transfer expanding to the transcontinental distance. In this paper, the first Q-TWTT experimental demonstration over a hybrid link of 2 km-long turbulent free space and 7 km-long field fiber is reported. Despite th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.01741v1-abstract-full').style.display = 'inline'; document.getElementById('2212.01741v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.01741v1-abstract-full" style="display: none;"> As the superiority of quantum two-way time transfer (Q-TWTT) has been proved convincingly over fiber links, its implementation on free-space links becomes an urgent need for remote time transfer expanding to the transcontinental distance. In this paper, the first Q-TWTT experimental demonstration over a hybrid link of 2 km-long turbulent free space and 7 km-long field fiber is reported. Despite the significant loss of more than 25 dB and atmospheric turbulence, reliable time transfer performance lasting for overnights has been realized with time stability in terms of time deviation far below 1 picosecond. This achievement shows the good feasibility of quantum-enhanced time transfer in the space-ground integrated optical links and nicely certifies the capability of Q-TWTT in comparing and synchronizing the state-of-the-art space microwave atomic clocks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.01741v1-abstract-full').style.display = 'none'; document.getElementById('2212.01741v1-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 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">13 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/2211.05341">arXiv:2211.05341</a> <span> [<a href="https://arxiv.org/pdf/2211.05341">pdf</a>, <a href="https://arxiv.org/format/2211.05341">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.131.080401">10.1103/PhysRevLett.131.080401 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Quantum simulation of topological zero modes on a 41-qubit superconducting processor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Shi%2C+Y">Yun-Hao Shi</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+Y">Yu Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+Y">Yu-Ran Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Xiang%2C+Z">Zhongcheng Xiang</a>, <a href="/search/quant-ph?searchtype=author&query=Huang%2C+K">Kaixuan Huang</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tao Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yong-Yi Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zhang%2C+J">Jia-Chi Zhang</a>, <a href="/search/quant-ph?searchtype=author&query=Deng%2C+C">Cheng-Lin Deng</a>, <a href="/search/quant-ph?searchtype=author&query=Liang%2C+G">Gui-Han Liang</a>, <a href="/search/quant-ph?searchtype=author&query=Mei%2C+Z">Zheng-Yang Mei</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+H">Hao Li</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+T">Tian-Ming Li</a>, <a href="/search/quant-ph?searchtype=author&query=Ma%2C+W">Wei-Guo Ma</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+H">Hao-Tian Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Chen%2C+C">Chi-Tong Chen</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tong Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Tian%2C+Y">Ye Tian</a>, <a href="/search/quant-ph?searchtype=author&query=Song%2C+X">Xiaohui Song</a>, <a href="/search/quant-ph?searchtype=author&query=Zhao%2C+S+P">S. P. Zhao</a>, <a href="/search/quant-ph?searchtype=author&query=Xu%2C+K">Kai Xu</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+D">Dongning Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Nori%2C+F">Franco Nori</a>, <a href="/search/quant-ph?searchtype=author&query=Fan%2C+H">Heng Fan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.05341v2-abstract-short" style="display: inline;"> Quantum simulation of different exotic topological phases of quantum matter on a noisy intermediate-scale quantum (NISQ) processor is attracting growing interest. Here, we develop a one-dimensional 43-qubit superconducting quantum processor, named as Chuang-tzu, to simulate and characterize emergent topological states. By engineering diagonal Aubry-Andr$\acute{\mathrm{e}}$-Harper (AAH) models, we… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.05341v2-abstract-full').style.display = 'inline'; document.getElementById('2211.05341v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.05341v2-abstract-full" style="display: none;"> Quantum simulation of different exotic topological phases of quantum matter on a noisy intermediate-scale quantum (NISQ) processor is attracting growing interest. Here, we develop a one-dimensional 43-qubit superconducting quantum processor, named as Chuang-tzu, to simulate and characterize emergent topological states. By engineering diagonal Aubry-Andr$\acute{\mathrm{e}}$-Harper (AAH) models, we experimentally demonstrate the Hofstadter butterfly energy spectrum. Using Floquet engineering, we verify the existence of the topological zero modes in the commensurate off-diagonal AAH models, which have never been experimentally realized before. Remarkably, the qubit number over 40 in our quantum processor is large enough to capture the substantial topological features of a quantum system from its complex band structure, including Dirac points, the energy gap's closing, the difference between even and odd number of sites, and the distinction between edge and bulk states. Our results establish a versatile hybrid quantum simulation approach to exploring quantum topological systems in the NISQ era. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.05341v2-abstract-full').style.display = 'none'; document.getElementById('2211.05341v2-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 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Main text: 6 pages, 4 figures; Supplementary: 16 pages, 14 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 131.080401 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.16518">arXiv:2210.16518</a> <span> [<a href="https://arxiv.org/pdf/2210.16518">pdf</a>, <a href="https://arxiv.org/format/2210.16518">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Biomolecules">q-bio.BM</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"> ViSNet: an equivariant geometry-enhanced graph neural network with vector-scalar interactive message passing for molecules </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Y">Yusong Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+S">Shaoning Li</a>, <a href="/search/quant-ph?searchtype=author&query=He%2C+X">Xinheng He</a>, <a href="/search/quant-ph?searchtype=author&query=Li%2C+M">Mingyu Li</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+Z">Zun Wang</a>, <a href="/search/quant-ph?searchtype=author&query=Zheng%2C+N">Nanning Zheng</a>, <a href="/search/quant-ph?searchtype=author&query=Shao%2C+B">Bin Shao</a>, <a href="/search/quant-ph?searchtype=author&query=Liu%2C+T">Tie-Yan Liu</a>, <a href="/search/quant-ph?searchtype=author&query=Wang%2C+T">Tong 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="2210.16518v3-abstract-short" style="display: inline;"> Geometric deep learning has been revolutionizing the molecular modeling field. Despite the state-of-the-art neural network models are approaching ab initio accuracy for molecular property prediction, their applications, such as drug discovery and molecular dynamics (MD) simulation, have been hindered by insufficient utilization of geometric information and high computational costs. Here we propose… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.16518v3-abstract-full').style.display = 'inline'; document.getElementById('2210.16518v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.16518v3-abstract-full" style="display: none;"> Geometric deep learning has been revolutionizing the molecular modeling field. Despite the state-of-the-art neural network models are approaching ab initio accuracy for molecular property prediction, their applications, such as drug discovery and molecular dynamics (MD) simulation, have been hindered by insufficient utilization of geometric information and high computational costs. Here we propose an equivariant geometry-enhanced graph neural network called ViSNet, which elegantly extracts geometric features and efficiently models molecular structures with low computational costs. Our proposed ViSNet outperforms state-of-the-art approaches on multiple MD benchmarks, including MD17, revised MD17 and MD22, and achieves excellent chemical property prediction on QM9 and Molecule3D datasets. Additionally, ViSNet achieved the top winners of PCQM4Mv2 track in the OGB-LCS@NeurIPS2022 competition. Furthermore, through a series of simulations and case studies, ViSNet can efficiently explore the conformational space and provide reasonable interpretability to map geometric representations to molecular structures. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.16518v3-abstract-full').style.display = 'none'; document.getElementById('2210.16518v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 29 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a 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