Quantum Science and Technology最新文献

From architectures to applications: a review of neural quantum states 从架构到应用：神经量子态综述

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-29 DOI: 10.1088/2058-9565/ad7168

Hannah Lange, Anka Van de Walle, Atiye Abedinnia and Annabelle Bohrdt

引用次数: 0

OPA tomography of non-Gaussian states of light 光的非高斯态 OPA 层析成像技术

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-26 DOI: 10.1088/2058-9565/ad7a9d

Éva Rácz, László Ruppert and Radim Filip

引用次数: 0

A linear photonic swap test circuit for quantum kernel estimation 用于量子核估计的线性光子交换测试电路

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-25 DOI: 10.1088/2058-9565/ad7be7

Alessio Baldazzi, Nicolò Leone, Matteo Sanna, Stefano Azzini and Lorenzo Pavesi

{"title":"A linear photonic swap test circuit for quantum kernel estimation","authors":"Alessio Baldazzi, Nicolò Leone, Matteo Sanna, Stefano Azzini and Lorenzo Pavesi","doi":"10.1088/2058-9565/ad7be7","DOIUrl":"https://doi.org/10.1088/2058-9565/ad7be7","url":null,"abstract":"The swap test is a quantum algorithm capable of computing the absolute value of the scalar product of two arbitrary wavefunctions. Scalar products represent a crucial ingredient to many quantum machine learning (QML) methods, but their evaluation is not straightforward at all. For this reason, many research efforts have been made without achieving an efficient and robust implementation. Here, we present an integrated photonic circuit designed to implement the swap test algorithm. Our approach relies solely on linear optical integrated components and qudits, represented by single photons from an attenuated laser beam propagating through a set of waveguides. By utilizing 23 spatial degrees of freedom for the qudits, we can configure all the necessary arrangements to set any two-qubit state and perform the swap test. This simplifies the requirements on the circuitry elements and eliminates the need for non-linearity, heralding, or post-selection to achieve multi-qubit gates. Our photonic swap test circuit successfully encodes two qubits and estimates their scalar product with a measured root mean square error smaller than 0.05. This result paves the way for the development of integrated photonic architectures capable of performing QML tasks with robust devices operating at room temperature.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321655","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

Verifiable quantum homomorphic encryption based on garbled evaluation 基于乱码评估的可验证量子同态加密

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-23 DOI: 10.1088/2058-9565/ad7a9c

Renke He, Lingli Chen, Qin Li, Xiaoqing Tan and Lv Chen

引用次数: 0

On the feasibility of detecting quantum delocalization effects on relativistic time dilation in optical clocks 论探测量子脱焦效应对光学时钟相对论时间膨胀的可行性

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-23 DOI: 10.1088/2058-9565/ad752c

Yanglin Hu (胡杨林), Maximilian P E Lock and Mischa P Woods

{"title":"On the feasibility of detecting quantum delocalization effects on relativistic time dilation in optical clocks","authors":"Yanglin Hu (胡杨林), Maximilian P E Lock and Mischa P Woods","doi":"10.1088/2058-9565/ad752c","DOIUrl":"https://doi.org/10.1088/2058-9565/ad752c","url":null,"abstract":"We derive the predicted time dilation of delocalized atomic clocks in an optical lattice setup in the presence of a gravitational field to leading order in quantum relativistic corrections. We investigate exotic quantum states of motion whose relativistic time dilation is outside of the realm of classical general relativity, finding a regime where optical lattice clocks currently in development would comfortably be able to detect the special-relativistic contribution to the quantum effect (if the technical challenge of generating the necessary states can be met and the expected accuracy of such clocks can be attained). We find that the gravitational contribution, on the other hand, is negligible in this setup. We provide a detailed experimental protocol and analyse the effects of noise on our predictions. We also show that the magnitude of our predicted quantum time dilation effect remains just out of detectable reach for the current generation of optical lattice clocks. Our calculations agree with the predicted time dilation of classical general relativity when restricting to Gaussian states.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313585","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

Practical twin-field quantum key distribution parameter optimization based on quantum annealing algorithm 基于量子退火算法的实用双场量子密钥分发参数优化

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-23 DOI: 10.1088/2058-9565/ad7b6f

Yue Li, Zhongqi Sun, Haoyang Wang, Kaiyi Shi, Jiaao Li, Chang Liu and Haiqiang Ma

{"title":"Practical twin-field quantum key distribution parameter optimization based on quantum annealing algorithm","authors":"Yue Li, Zhongqi Sun, Haoyang Wang, Kaiyi Shi, Jiaao Li, Chang Liu and Haiqiang Ma","doi":"10.1088/2058-9565/ad7b6f","DOIUrl":"https://doi.org/10.1088/2058-9565/ad7b6f","url":null,"abstract":"Twin-field quantum key distribution (TF-QKD) is widely studied since it can surpass the key capacity of repeaterless QKD, whereas electromagnetic interference (EMI) is one of the main challenges in its practical applications. This study is based on the Faraday–Michelson TF-QKD. Analyze the effect of EMI on the rotation angle of the Faraday mirror causing an additional quantum bit error rate (QBER). Moreover, the quantum annealing algorithm (QA) based on quantum tunneling mechanism is applied to the optimization of practical TF-QKD. Mapping the secure key rate of TF-QKD into the evaluation function of QA and the transverse magnetic field is introduced to construct the kinetic energy term, which can realize the quantum tunneling effect. Meanwhile, the QA is improved in terms of chaotic optimization to obtain the dynamic initial value of the algorithm, the design of a perturbation method to skip the locally optimal solution, and the use of suitable temperature and magnetic field decay functions. Optimizing TF-QKD with QA, the standard deviation of QBER fluctuation caused by EMI is reduced to 0.206, the mean square error of the signal-state pulse intensity is only , and the optimization accuracy of the secure key rate can reach 99.8 . Additionally, this optimization method shortens the runtime and reduces computational resource consumption, making it highly efficient for practical implementations.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313570","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

Synthesis of energy-conserving quantum circuits with XY interaction 具有 XY 相互作用的能量守恒量子电路的合成

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-19 DOI: 10.1088/2058-9565/ad53fa

Ge Bai and Iman Marvian

{"title":"Synthesis of energy-conserving quantum circuits with XY interaction","authors":"Ge Bai and Iman Marvian","doi":"10.1088/2058-9565/ad53fa","DOIUrl":"https://doi.org/10.1088/2058-9565/ad53fa","url":null,"abstract":"We study quantum circuits constructed from gates and, more generally, from the entangling gates that can be realized with the XX + YY interaction alone. Such gates preserve the Hamming weight of states in the computational basis, which means they respect the global U(1) symmetry corresponding to rotations around the z axis. Equivalently, assuming that the intrinsic Hamiltonian of each qubit in the system is the Pauli Z operator, they conserve the total energy of the system. We develop efficient methods for synthesizing circuits realizing any desired energy-conserving unitary using XX + YY interaction with or without single-qubit rotations around the z axis. Interestingly, implementing generic energy-conserving unitaries, such as CCZ and Fredkin gates, with two-local energy-conserving gates requires the use of ancilla qubits. When single-qubit rotations around the z-axis are permitted, our scheme requires only a single ancilla qubit, whereas with the XX+YY interaction alone, it requires two ancilla qubits. In addition to exact realizations, we also consider approximate realizations and show how a general energy-conserving unitary can be synthesized using only a sequence of gates and two ancillary qubits, with arbitrarily small error, which can be bounded via the Solovay–Kitaev theorem. Our methods are also applicable for synthesizing energy-conserving unitaries when, rather than the XX + YY interaction, one has access to any other energy-conserving two-body interaction that is not diagonal in the computational basis, such as the Heisenberg exchange interaction. We briefly discuss the applications of these circuits in the context of quantum computing, quantum thermodynamics, and quantum clocks.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142275621","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

Resonator-mediated quantum gate between distant charge qubits 遥远电荷量子比特之间的谐振器介导量子门

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-18 DOI: 10.1088/2058-9565/ad7756

Florian Kayatz, Jonas Mielke and Guido Burkard

引用次数: 0

Metrological robustness of high photon number optical cat states 高光子数光学猫态的计量稳健性

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-18 DOI: 10.1088/2058-9565/ad7881

Philipp Stammer, Tomás Fernández Martos, Maciej Lewenstein and Grzegorz Rajchel-Mieldzioć

{"title":"Metrological robustness of high photon number optical cat states","authors":"Philipp Stammer, Tomás Fernández Martos, Maciej Lewenstein and Grzegorz Rajchel-Mieldzioć","doi":"10.1088/2058-9565/ad7881","DOIUrl":"https://doi.org/10.1088/2058-9565/ad7881","url":null,"abstract":"In the domain of quantum metrology, cat states have demonstrated their utility despite their inherent fragility with respect to losses. Here, we introduce noise robust optical cat states which exhibit a metrological robustness for phase estimation in the regime of high photon numbers. These cat states are obtained from the intense laser driven process of high harmonic generation (HHG), and show a resilience against photon losses. Focusing on a realistic scenario including experimental imperfections we opt for the case in which we can maximize the lower bound of the quantum Fisher information (QFI) instead of analyzing the best case scenario. We show that the decrease of the QFI in the lossy case is suppressed for the HHG-cat state compared to the even and odd counterparts. In the regime of small losses of just a single photon, the HHG-cat state remains almost pure while the even/odd cat state counterparts rapidly decohere to the maximally mixed state. More importantly, this translates to a significantly enhanced robustness for the HHG-cat against photon loss, demonstrating that high photon number optical cat states can indeed be used for metrological applications even in the presence of losses.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142245178","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

An optical atomic clock using 4 D J ... 使用 4 D J 的光学原子钟 ...

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2024-09-16 DOI: 10.1088/2058-9565/ad77ef

A Duspayev, C Owens, B Dash and G Raithel

{"title":"An optical atomic clock using 4 D J ...","authors":"A Duspayev, C Owens, B Dash and G Raithel","doi":"10.1088/2058-9565/ad77ef","DOIUrl":"https://doi.org/10.1088/2058-9565/ad77ef","url":null,"abstract":"We analyze an optical atomic clock using two-photon transitions in rubidium. Four one- and two-color excitation schemes to probe the and fine-structure states are considered in detail. We compare key characteristics of Rb and two-photon clocks. The clock features a high signal-to-noise ratio due to two-photon decay at favorable wavelengths, low dc electric and magnetic susceptibilities, and minimal black-body shifts. Ac Stark shifts from the clock interrogation lasers are compensated by two-color Rabi-frequency matching. We identify a 'magic' wavelength near 1060 nm, which allows for in-trap, Doppler-free clock-transition interrogation with lattice-trapped cold atoms. From our analysis of clock statistics and systematics, we project a quantum-noise-limited relative clock stability at the -level, with integration time τ in seconds, and a relative accuracy of . We describe a potential architecture for implementing the proposed clock using a single telecom clock laser at 1550 nm, which is conducive to optical communication and long-distance clock comparisons. Our work could be of interest in efforts to realize small and portable Rb clocks and in high-precision measurements of atomic properties of Rb -states.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142235243","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