arXiv - PHYS - Quantum Physics最新文献_第4页

Quantifying nonclassical correlation via the generalized Wigner-Yanase skew information 通过广义 Wigner-Yanase 偏斜信息量化非经典相关性

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11198

Yan Hong, Xinlan Hao, Limin Gao

{"title":"Quantifying nonclassical correlation via the generalized Wigner-Yanase skew information","authors":"Yan Hong, Xinlan Hao, Limin Gao","doi":"arxiv-2409.11198","DOIUrl":"https://doi.org/arxiv-2409.11198","url":null,"abstract":"Nonclassical correlation is an important concept in quantum information\u0000theory, referring to a special type of correlation that exists between quantum\u0000systems, which surpasses the scope of classical physics. In this paper, we\u0000introduce the concept of a family of information with important properties,\u0000namely the generalized Wigner-Yanase skew information, of which the famous\u0000quantum Fisher information and Wigner-Yanase skew information are special\u0000cases.We classify the local observables in the generalized Wigner-Yanase skew\u0000information into two categories (i.e., orthonormal bases and a Hermitian\u0000operator with a fixed nondegenerate spectrum), and based on this, we propose\u0000two different forms of indicators to quantify nonclassical correlations of\u0000bipartite quantum states. We have not only investigated some important\u0000properties of these two kinds of indicators but also illustrated through\u0000specific examples that they can indeed capture some nonclassical correlations.\u0000Furthermore, we find that these two types of indicators reduce to entanglement\u0000measure for bipartite pure states. Specifically, we also derive the\u0000relationship between these two indicators and the entanglement measure\u0000$I$-concurrence.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Challenging Excited States from Adaptive Quantum Eigensolvers: Subspace Expansions vs. State-Averaged Strategies 挑战自适应量子均衡器的激发态：子空间展开与状态平均策略

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11210

Harper R. Grimsley, Francesco A. Evangelista

{"title":"Challenging Excited States from Adaptive Quantum Eigensolvers: Subspace Expansions vs. State-Averaged Strategies","authors":"Harper R. Grimsley, Francesco A. Evangelista","doi":"arxiv-2409.11210","DOIUrl":"https://doi.org/arxiv-2409.11210","url":null,"abstract":"The prediction of electronic structure for strongly correlated molecules\u0000represents a promising application for near-term quantum computers. Significant\u0000attention has been paid to ground state wavefunctions, but excited states of\u0000molecules are relatively unexplored. In this work, we consider the ADAPT-VQE\u0000algorithm, a single-reference approach for obtaining ground states, and its\u0000state-averaged generalization for computing multiple states at once. We\u0000demonstrate for both rectangular and linear H$_4$, as well as for BeH$_2$, that\u0000this approach, which we call MORE-ADAPT-VQE, can make better use of small\u0000excitation manifolds than an analagous method based on a single-reference\u0000ADAPT-VQE calculation, q-sc-EOM. In particular, MORE-ADAPT-VQE is able to\u0000accurately describe both avoided crossings and crossings between states of\u0000different symmetries. In addition to more accurate excited state energies,\u0000MORE-ADAPT-VQE can recover accurate transition dipole moments in situations\u0000where traditional ADAPT-VQE and q-sc-EOM struggle. These improvements suggest a\u0000promising direction toward the use of quantum computers for difficult excited\u0000state problems.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multiphoton interference in a single-spatial-mode quantum walk 单空间模式量子行走中的多光子干扰

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11483

Kate L. Fenwick, Jonathan Baker, Guillaume S. Thekkadath, Aaron Z. Goldberg, Khabat Heshami, Philip J. Bustard, Duncan England, Frédéric Bouchard, Benjamin Sussman

{"title":"Multiphoton interference in a single-spatial-mode quantum walk","authors":"Kate L. Fenwick, Jonathan Baker, Guillaume S. Thekkadath, Aaron Z. Goldberg, Khabat Heshami, Philip J. Bustard, Duncan England, Frédéric Bouchard, Benjamin Sussman","doi":"arxiv-2409.11483","DOIUrl":"https://doi.org/arxiv-2409.11483","url":null,"abstract":"Multiphoton interference is crucial to many photonic quantum technologies. In\u0000particular, interference forms the basis of optical quantum information\u0000processing platforms and can lead to significant computational advantages. It\u0000is therefore interesting to study the interference arising from various states\u0000of light in large interferometric networks. Here, we implement a quantum walk\u0000in a highly stable, low-loss, multiport interferometer with up to 24 ultrafast\u0000time bins. This time-bin interferometer comprises a sequence of birefringent\u0000crystals which produce pulses separated by 4.3,ps, all along a single optical\u0000axis. Ultrafast Kerr gating in an optical fiber is employed to time-demultiplex\u0000the output from the quantum walk. We measure one-, two-, and three-photon\u0000interference arising from various input state combinations, including a\u0000heralded single-photon state, a thermal state, and an attenuated coherent state\u0000at one or more input ports. Our results demonstrate that ultrafast time bins\u0000are a promising platform to observe large-scale multiphoton interference.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluating Modifications to Classifiers for Identification of Higgs Bosons 评估为识别希格斯玻色子而对分类器进行的修改

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.10902

Rishivarshil Nelakurti, Christopher Hill

引用次数: 0

Modeling a frustrated Ising square lattice with the D-Wave Quantum Annealer 用 D-Wave 量子退火器模拟受挫伊辛方阵

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11259

C. Marin, A. Fontana, V. Bellani, F. Pederiva, A. Quaranta, F. Rossella, A. Salamon, G. Salina

{"title":"Modeling a frustrated Ising square lattice with the D-Wave Quantum Annealer","authors":"C. Marin, A. Fontana, V. Bellani, F. Pederiva, A. Quaranta, F. Rossella, A. Salamon, G. Salina","doi":"arxiv-2409.11259","DOIUrl":"https://doi.org/arxiv-2409.11259","url":null,"abstract":"The Ising model with nearest-neighbor interactions on a two-dimensional (2D)\u0000square lattice is one of the simplest models for studying ferro-magnetic to\u0000para-magnetic transitions. Extensive results are available in the literature\u0000for this model, which has become a paradigm for the study of magnetic phase\u0000transitions in materials, both theoretically and numerically. After a brief\u0000review of the main results obtained with a classical computer, we show how to\u0000implement on the D- Wave quantum annealer a more complex Ising model with the\u0000addition of competing antiferromagnetic interactions between the diagonal\u0000next-to-nearest neighbors with two coupling constants J1 and J2. The dynamics\u0000of this system, owing to frustration, are richer than those of the simple Ising\u0000model and exhibit a third striped (or antiferromagnetic) phase in addition to\u0000the ferro- and para-magnetic phases. In this work, we observed all three phases\u0000on the D-Wave hardware, studied the behavior of the solution with different\u0000annealing parameters, such as the chain strength and annealing time, and showed\u0000how to identify the phase transition by varying the ratio between the\u0000ferromagnetic and antiferromagnetic couplings. The same system is studied on a\u0000classical computer, with the possibility of taking into account the temperature\u0000(fixed on D-Wave) as a free parameter and to explore the full phase diagram:\u0000some comparative conclusions with D-Wave are drawn.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hardware-Efficient Preparation of Graph States on Near-Term Quantum Computers 在近端量子计算机上以硬件高效方式制备图状态

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.10807

Sebastian Brandhofer, Ilia Polian, Stefanie Barz, Daniel Bhatti

{"title":"Hardware-Efficient Preparation of Graph States on Near-Term Quantum Computers","authors":"Sebastian Brandhofer, Ilia Polian, Stefanie Barz, Daniel Bhatti","doi":"arxiv-2409.10807","DOIUrl":"https://doi.org/arxiv-2409.10807","url":null,"abstract":"Highly entangled quantum states are an ingredient in numerous applications in\u0000quantum computing. However, preparing these highly entangled quantum states on\u0000currently available quantum computers at high fidelity is limited by ubiquitous\u0000errors. Besides improving the underlying technology of a quantum computer, the\u0000scale and fidelity of these entangled states in near-term quantum computers can\u0000be improved by specialized compilation methods. In this work, the compilation\u0000of quantum circuits for the preparation of highly entangled\u0000architecture-specific graph states is addressed by defining and solving a\u0000formal model. Our model incorporates information about gate cancellations, gate\u0000commutations, and accurate gate timing to determine an optimized graph state\u0000preparation circuit. Up to now, these aspects have only been considered\u0000independently of each other, typically applied to arbitrary quantum circuits.\u0000We quantify the quality of a generated state by performing stabilizer\u0000measurements and determining its fidelity. We show that our new method reduces\u0000the error when preparing a seven-qubit graph state by 3.5x on average compared\u0000to the state-of-the-art Qiskit solution. For a linear eight-qubit graph state,\u0000the error is reduced by 6.4x on average. The presented results highlight the\u0000ability of our approach to prepare higher fidelity or larger-scale graph states\u0000on gate-based quantum computing hardware.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unsupervised state learning from pairs of states 从成对状态中进行无监督状态学习

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11120

Pranjal Agarwal, Nada Ali, Camilla Polvara, Martin Isbjörn Trappe, Berthold-Georg Englert, Mark Hillery

引用次数: 0

Direct experimental observation of sub-poissonian photon statistics by means of multi-photon scattering on a two-level system 通过两级系统上的多光子散射，直接实验观测亚极松光子统计量

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.10975

A. Yu. Dmitriev, A. V. Vasenin, S. A. Gunin, S. V. Remizov, A. A. Elistratov, W. V. Pogosov, O. V. Astafiev

{"title":"Direct experimental observation of sub-poissonian photon statistics by means of multi-photon scattering on a two-level system","authors":"A. Yu. Dmitriev, A. V. Vasenin, S. A. Gunin, S. V. Remizov, A. A. Elistratov, W. V. Pogosov, O. V. Astafiev","doi":"arxiv-2409.10975","DOIUrl":"https://doi.org/arxiv-2409.10975","url":null,"abstract":"A cascade of two-level superconducting artificial atoms -- a source and a\u0000probe -- strongly coupled to a semi-infinite waveguide is a promising tool for\u0000observing nontrivial phenomena in quantum nonlinear optics. The probe atom can\u0000scatter an antibunched radiation emitted from the source, thereby generating a\u0000field with specific properties. We experimentally demonstrate wave mixing\u0000between nonclassical light from the coherently cw-pumped source and another\u0000coherent wave acting on the probe. We observe unique features in the wave\u0000mixing stationary spectrum which differs from mixing spectrum of two classical\u0000waves on the probe. These features are well described by adapting the theory\u0000for a strongly coupled cascaded system of two atoms. We further analyze the\u0000theory to predict non-classical mixing spectra for various ratios of atoms'\u0000radiative constants. Both experimental and numerical results confirm the\u0000domination of multi-photon scattering process with only a single photon from\u0000the source. We evaluate entanglement of atoms in the quasistationary state and\u0000illustrate the connection between the expected second-order correlation\u0000function of source's field and wave mixing side peaks corresponding to a\u0000certain number of scattered photons.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electrons herald non-classical light 电子预示着非经典光

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11300

Germaine Arend, Guanhao Huang, Armin Feist, Yujia Yang, Jan-Wilke Henke, Zheru Qiu, Hao Jeng, Arslan Sajid Raja, Rudolf Haindl, Rui Ning Wang, Tobias J. Kippenberg, Claus Ropers

{"title":"Electrons herald non-classical light","authors":"Germaine Arend, Guanhao Huang, Armin Feist, Yujia Yang, Jan-Wilke Henke, Zheru Qiu, Hao Jeng, Arslan Sajid Raja, Rudolf Haindl, Rui Ning Wang, Tobias J. Kippenberg, Claus Ropers","doi":"arxiv-2409.11300","DOIUrl":"https://doi.org/arxiv-2409.11300","url":null,"abstract":"Free electrons are a widespread and universal source of electromagnetic\u0000fields. The past decades witnessed ever-growing control over many aspects of\u0000electron-generated radiation, from the incoherent emission produced by X-ray\u0000tubes to the exceptional brilliance of free-electron lasers. Reduced to the\u0000elementary process of quantized energy exchange between individual electrons\u0000and the electromagnetic field, electron beams may facilitate future sources of\u0000tunable quantum light. However, the quantum features of such radiation are tied\u0000to the correlation of the particles, calling for the joint electronic and\u0000photonic state to be explored for further applications. Here, we demonstrate\u0000the coherent parametric generation of non-classical states of light by free\u0000electrons. We show that the quantized electron energy loss heralds the number\u0000of photons generated in a dielectric waveguide. In Hanbury-Brown-Twiss\u0000measurements, an electron-heralded single-photon state is revealed via\u0000antibunching intensity correlations, while two-quantum energy losses of\u0000individual electrons yield pronounced two-photon coincidences. The approach\u0000facilitates the tailored preparation of higher-number Fock and other optical\u0000quantum states based on controlled interactions with free-electron beams.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Violation of no-signaling on a public quantum computer 违反公共量子计算机的无信号规定

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-17 DOI: arxiv-2409.11348

Tomasz Rybotycki, Tomasz Białecki, Josep Batle, Adam Bednorz

引用次数: 0