Physical Review A最新文献_第2页

Shallow-depth variational quantum hypothesis testing 浅层变分量子假设检验

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-18 DOI: 10.1103/physreva.110.032424

Mahadevan Subramanian, Sai Vinjanampathy

引用次数: 0

Reliable quantum memories with unreliable components 使用不可靠组件的可靠量子存储器

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-18 DOI: 10.1103/physreva.110.032423

Anuj K. Nayak, Eric Chitambar, Lav R. Varshney

{"title":"Reliable quantum memories with unreliable components","authors":"Anuj K. Nayak, Eric Chitambar, Lav R. Varshney","doi":"10.1103/physreva.110.032423","DOIUrl":"https://doi.org/10.1103/physreva.110.032423","url":null,"abstract":"Quantum memory systems are vital in quantum information processing for dependable storage and retrieval of quantum states. Inspired by classical reliability theories that synthesize reliable computing systems from unreliable components, we formalize the problem of reliable storage of quantum information using noisy components. We introduce the notion of stable quantum memories and define the storage rate as the ratio of the number of logical qubits to the total number of physical qubits as well as the circuit complexity of the decoder, which includes both quantum gates and measurements. We demonstrate that a strictly positive storage rate can be achieved by constructing a quantum memory system with quantum expander codes. Moreover, by reducing the reliable storage problem to reliable quantum communication, we provide upper bounds on the achievable storage capacity. In the case of physical qubits corrupted by noise satisfying hypercontractivity conditions, we provide a tighter upper bound on storage capacity using an entropy dissipation argument. Furthermore, observing that the time complexity of the decoder scales nontrivially with the number of physical qubits, achieving asymptotic rates may not be possible due to the induced dependence of the noise on the number of physical qubits. In this constrained nonasymptotic setting, we derive upper bounds on storage capacity using finite blocklength communication bounds. Finally, we numerically analyze the gap between upper and lower bounds in both asymptotic and nonasymptotic cases, and provide suggestions to tighten the gap.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"49 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Swallow-tail dispersions of moving solitons in a two-dimensional fermionic superfluid 二维费米子超流体中运动孤子的燕尾色散

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-18 DOI: 10.1103/physreva.110.033320

Jan Major, Joachim Brand

引用次数: 0

Effects of the chirp rate on single-shot coherent Rayleigh-Brillouin scattering 啁啾率对单次相干瑞利-布里渊散射的影响

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-18 DOI: 10.1103/physreva.110.033519

S. Suzuki, A. Gerakis, K. Hara

引用次数: 0

Vacuum-polarization Wichmann-Kroll correction in the finite-basis-set approach 有限基础集方法中的真空极化 Wichmann-Kroll 校正

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-18 DOI: 10.1103/physreva.110.032815

V. K. Ivanov, S. S. Baturin, D. A. Glazov, A. V. Volotka

引用次数: 0

Direct measurement of isotope shifts in the barium 6s2 S01–5d6p D1o3 transition 直接测量钡 6s2 S01-5d6p D1o3 转变中的同位素偏移

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-17 DOI: 10.1103/physreva.110.032812

Jungwoo Choi, Eunhwi Lee, Dahyun Yum, Kyungwon An, Junki Kim

{"title":"Direct measurement of isotope shifts in the barium 6s2 S01–5d6p D1o3 transition","authors":"Jungwoo Choi, Eunhwi Lee, Dahyun Yum, Kyungwon An, Junki Kim","doi":"10.1103/physreva.110.032812","DOIUrl":"https://doi.org/10.1103/physreva.110.032812","url":null,"abstract":"We report the direct measurement of isotope shifts of the barium <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>6</mn><msup><mrow><mi>s</mi></mrow><mn>2</mn></msup></mrow></math> <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mmultiscripts><mi>S</mi><mn>0</mn><none></none><mprescripts></mprescripts><none></none><mn>1</mn></mmultiscripts><mtext>–</mtext><mn>5</mn><mi>d</mi><mn>6</mn><mi>p</mi><mmultiscripts><mi>D</mi><mn>1</mn><mi mathvariant=\"normal\">o</mi><mprescripts></mprescripts><none></none><mn>3</mn></mmultiscripts></mrow></math> 413-nm electric quadrupole transition, which is utilized for efficient barium ion trapping via photoionization using a single coherent light source. The measured isotope shifts relative to <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mmultiscripts><mi>Ba</mi><mprescripts></mprescripts><none></none><mn>138</mn></mmultiscripts></math> are <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>392.9</mn><mo>±</mo><mn>0.9</mn><mspace width=\"0.16em\"></mspace><mi>MHz</mi></mrow></math>, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>178.1</mn><mo>±</mo><mn>0.8</mn><mspace width=\"0.16em\"></mspace><mi>MHz</mi></mrow></math>, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>401.4</mn><mo>±</mo><mn>1.2</mn><mspace width=\"0.16em\"></mspace><mi>MHz</mi></mrow></math>, and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>124.3</mn><mo>±</mo><mn>1.3</mn><mspace width=\"0.16em\"></mspace><mi>MHz</mi></mrow></math> for isotopes with atomic numbers 137, 136, 135, and 134, respectively. We verify the measured isotopes with King plot analysis and compare the result with the formerly known shifts inferred from previous studies on neighboring transitions. The results can be used for efficient isotope selective loading of low-abundant barium ions, while careful suppression of line broadening is required for successful isotopic selectivity.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"20 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exceptional points in perturbed dielectric spheres: A resonant-state expansion study 扰动介质球中的异常点：共振态扩展研究

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-17 DOI: 10.1103/physreva.110.033518

K. S. Netherwood, H. K. Riley, E. A. Muljarov

{"title":"Exceptional points in perturbed dielectric spheres: A resonant-state expansion study","authors":"K. S. Netherwood, H. K. Riley, E. A. Muljarov","doi":"10.1103/physreva.110.033518","DOIUrl":"https://doi.org/10.1103/physreva.110.033518","url":null,"abstract":"Exceptional points (EPs) in open optical systems are rigorously studied using the resonant-state expansion (RSE). A spherical resonator, specifically a homogeneous dielectric sphere in a vacuum, perturbed by two pointlike defects which break the spherical symmetry and bring the optical modes to EPs, is used as a worked example. The RSE is a nonperturbative approach encoding the information about an open optical system in matrix form in a rigorous way, and thus offering a suitable tool for studying its EPs. These are simultaneous degeneracies of the eigenvalues and corresponding eigenfunctions of the system, which are rigorously described by the RSE and illustrated for perturbed whispering-gallery modes (WGMs). An exceptional arc, which is a line of adjacent EPs, is obtained analytically for perturbed dipolar WGMs. Perturbation of high-quality WGMs with large angular momentum and their EPs are found by reducing the RSE equation to a two-state problem by means of an orthogonal transformation of a large RSE matrix. WGM pairs have opposite chirality in spherically symmetric systems and equal chirality at EPs. This chirality at EPs can be observed in circular dichroism measurements, as it manifested itself in a squared-Lorentzian part of the optical spectra, which we demonstrate here analytically and numerically in the Purcell enhancement factor for the perturbed dipolar WGMs.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"27 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantum violations of joint reality 量子违反联合现实

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-17 DOI: 10.1103/physreva.110.032214

R. A. Caetano, R. M. Angelo

引用次数: 0

Cooperative atomic emission from a line of atoms interacting with a resonant plane surface 与共振平面表面相互作用的原子线的协同原子发射

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-17 DOI: 10.1103/physreva.110.032813

M. O. Araújo, J. C. de Aquino Carvalho, Ph. W. Courteille, A. Laliotis

{"title":"Cooperative atomic emission from a line of atoms interacting with a resonant plane surface","authors":"M. O. Araújo, J. C. de Aquino Carvalho, Ph. W. Courteille, A. Laliotis","doi":"10.1103/physreva.110.032813","DOIUrl":"https://doi.org/10.1103/physreva.110.032813","url":null,"abstract":"Cooperative effects such as super- and subradiance can be observed in the fluorescence emitted by a system of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>N</mi></math> atoms in vacuum after interaction with a laser beam. In the vicinity of a dielectric or metallic surface, Casimir-Polder effects can modify collective atomic frequency shifts and decay rates. In this work, we study cooperative fluorescent emission next to resonant surfaces using the coupled-dipole model. We show that cooperative effects, expected in free space, are absent when the atoms are close to a surface whose polariton resonances coincide with the dominant atomic dipole coupling. In this case, cooperative effects are overshadowed by the very fast decay of the atomic fluorescence into surface modes. We illustrate our formalism and our results by considering a line of cesium <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>6</mn><msub><mi>D</mi><mrow><mn>3</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></math> atoms in front of a sapphire surface. Finally, we propose the study of cesium <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>6</mn><msub><mi>P</mi><mrow><mn>3</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></math> atoms in front of a resonant metasurface as the most promising scenario for experimentally demonstrating the results of our study.","PeriodicalId":20146,"journal":{"name":"Physical Review A","volume":"118 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improving the performance of digitized counterdiabatic quantum optimization via algorithm-oriented qubit mapping 通过面向算法的量子比特映射提高数字化逆绝热量子优化的性能

IF 2.9 2区物理与天体物理

Physical Review A Pub Date : 2024-09-17 DOI: 10.1103/physreva.110.032421

Yanjun Ji, Kathrin F. Koenig, Ilia Polian

引用次数: 0