Quantum Science and Technology最新文献_第6页

Non-positive energy quasidistributions in coherent collision models 相干碰撞模型中的非正能量准分布

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-21 DOI: 10.1088/2058-9565/aded2e

Marco Pezzutto, Gabriele De Chiara and Stefano Gherardini

引用次数: 0

Adaptive-depth randomized measurement for fermionic observables 费米子观测值的自适应深度随机测量

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-20 DOI: 10.1088/2058-9565/adeeb9

Kaiming Bian and Bujiao Wu

{"title":"Adaptive-depth randomized measurement for fermionic observables","authors":"Kaiming Bian and Bujiao Wu","doi":"10.1088/2058-9565/adeeb9","DOIUrl":"https://doi.org/10.1088/2058-9565/adeeb9","url":null,"abstract":"Accurate estimation of fermionic observables is essential for advancing quantum physics and chemistry. The fermionic classical shadow (FCS) method offers an efficient framework for estimating these observables without requiring a transformation into a Pauli basis for k-local Fermionic observables. However, the random matchgate circuits in FCS require linear-depth circuits with a brickwork structure, which presents significant challenges for near-term quantum devices with limited computational resources. To address this limitation, we introduce an adaptive-depth fermionic classical shadow (ADFCS) protocol designed to reduce the circuit depth while maintaining the sample complexity. Through theoretical analysis and numerical fitting, we establish that the required depth for approximating a fermionic observable H is upper bounded by when the locality k is a constant, where dint is the interaction distance of H and n is the number of qubits. We demonstrate the effectiveness of the ADFCS protocol through numerical experiments, which show similar accuracy to the traditional FCS method while requiring significantly fewer quantum resources. Additionally, we apply ADFCS to compute the expectation value of the Kitaev chain Hamiltonian, further validating its performance in practical scenarios. Our findings suggest that ADFCS enables more efficient quantum simulations when the locality k is constant, reducing circuit depth while preserving the sample complexity and offering a viable solution for near-term quantum devices.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"12 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144669723","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 accurate and efficient analytic model of fidelity under depolarizing noise oriented to large scale quantum system design 面向大尺度量子系统设计的去极化噪声下保真度精确高效分析模型

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-16 DOI: 10.1088/2058-9565/aded2f

Pau Escofet, Santiago Rodrigo, Artur Garcia-Sáez, Eduard Alarcón, Sergi Abadal and Carmen G Almudéver

{"title":"An accurate and efficient analytic model of fidelity under depolarizing noise oriented to large scale quantum system design","authors":"Pau Escofet, Santiago Rodrigo, Artur Garcia-Sáez, Eduard Alarcón, Sergi Abadal and Carmen G Almudéver","doi":"10.1088/2058-9565/aded2f","DOIUrl":"https://doi.org/10.1088/2058-9565/aded2f","url":null,"abstract":"Fidelity is one of the most valuable and commonly used metrics for assessing the performance of quantum circuits on error-prone quantum processors. Several approaches have been proposed to estimate circuit fidelity without executing it on quantum hardware, but they often face limitations in scalability or accuracy. In this work, we present a comprehensive theoretical framework to predict the fidelity of quantum circuits under depolarizing noise. Building on theoretical results, we propose an efficient fidelity estimation algorithm based on device calibration data. The method is thoroughly validated through simulation and execution on real hardware, demonstrating improved accuracy compared to state-of-the-art alternatives, with enhancements in prediction R2 ranging from 4.96% to 213.54%. The proposed approach provides a scalable and practical tool for benchmarking quantum hardware, comparing quantum software techniques such as compilation methods, obtaining computation bounds for quantum systems, and guiding hardware design decisions, making it a critical resource for developing and evaluating quantum computing technologies.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"16 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144645627","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

Detrimental non-Markovian errors for surface code memory 表面代码存储器的有害非马尔可夫错误

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-15 DOI: 10.1088/2058-9565/adebab

John F Kam, Spiro Gicev, Kavan Modi, Angus Southwell and Muhammad Usman

引用次数: 0

Combining kinetic and thermodynamic uncertainty relations in quantum transport 结合量子输运中的动力学和热力学不确定性关系

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-14 DOI: 10.1088/2058-9565/ade623

Didrik Palmqvist, Ludovico Tesser and Janine Splettstoesser

{"title":"Combining kinetic and thermodynamic uncertainty relations in quantum transport","authors":"Didrik Palmqvist, Ludovico Tesser and Janine Splettstoesser","doi":"10.1088/2058-9565/ade623","DOIUrl":"https://doi.org/10.1088/2058-9565/ade623","url":null,"abstract":"We study the fluctuations of generic currents in multi-terminal, multi-channel coherent quantum transport settings. In the quantum regime, these fluctuations and the resulting precision differ strongly depending on whether the device is of fermionic or bosonic nature. Using scattering theory, we show that the precision is bounded by constraints set by the entropy production and by the activity in the spirit of thermodynamic or kinetic uncertainty relations, valid for fermionic and bosonic quantum systems also in the absence of time-reversal symmetry. Furthermore, we derive a combined thermodynamic kinetic uncertainty relation, which is tight over a wide range of parameters and can hence predict the reachable precision of a device. Since these constraints can be expressed in terms of observables accessible in transport measurements, such as currents and bandwidth, we foresee that the tight thermodynamic kinetic uncertainty-like bounds are also useful as an inference tool: they can be exploited to estimate entropy production from transport observables, such as the charge current and its noise, which are more easily accessible in experiment.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"66 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144630328","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

Storage of single photons from a semiconductor quantum dot in a room-temperature atomic vapor memory with on-demand retrieval 半导体量子点单光子在室温原子蒸气存储器中随需检索的存储

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-13 DOI: 10.1088/2058-9565/ade910

Benjamin Maaß, Avijit Barua, Norman Vincenz Ewald, Elizabeth Robertson, Kartik Gaur, Suk In Park, Sven Rodt, Jin-Dong Song, Stephan Reitzenstein and Janik Wolters

{"title":"Storage of single photons from a semiconductor quantum dot in a room-temperature atomic vapor memory with on-demand retrieval","authors":"Benjamin Maaß, Avijit Barua, Norman Vincenz Ewald, Elizabeth Robertson, Kartik Gaur, Suk In Park, Sven Rodt, Jin-Dong Song, Stephan Reitzenstein and Janik Wolters","doi":"10.1088/2058-9565/ade910","DOIUrl":"https://doi.org/10.1088/2058-9565/ade910","url":null,"abstract":"Interfacing light from solid-state single-photon sources with scalable and robust room-temperature quantum memories has been a long-standing challenge in photonic quantum information technologies due to inherent noise processes and time-scale mismatches between the operating conditions of solid-state and atomic systems. Here, we demonstrate storage of single photons from a semiconductor quantum dot (QD) device in a room-temperature atomic vapor memory and their on-demand retrieval. A deterministically fabricated InGaAs QD light source emits single photons at the wavelength of the cesium D1 line at 895 nm which exhibit an inhomogeneously broadened linewidth of 5.1(7) GHz and are subsequently stored in a low-noise ladder-type cesium vapor memory. We show control over the interaction between the single photons and the atomic vapor, allowing for variable retrieval times of up to 19.8(3) ns. A maximum internal efficiency of is achieved. Our results expand the application space of both room-temperature vapor memories and semiconductor QDs in future quantum network architectures.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"668 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144622245","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

Large amplitude mechanical coherent states and detection of weak nonlinearities in cavity optomechanics 腔光力学中大振幅力学相干态及弱非线性检测

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-03 DOI: 10.1088/2058-9565/ade8a0

Wenlin Li, Paolo Piergentili, Francesco Marzioni, Michele Bonaldi, Antonio Borrielli, Enrico Serra, Francesco Marin, Francesco Marino, Nicola Malossi, Riccardo Natali, Giovanni Di Giuseppe and David Vitali

引用次数: 0

From exponential to quadratic: optimal control for a frustrated Ising ring model 从指数到二次：受挫伊辛环模型的最优控制

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-01 DOI: 10.1088/2058-9565/ade6a5

Ruiyi Wang, Vincenzo Roberto Arezzo, Kiran Thengil, Giovanni Pecci and Giuseppe E Santoro

{"title":"From exponential to quadratic: optimal control for a frustrated Ising ring model","authors":"Ruiyi Wang, Vincenzo Roberto Arezzo, Kiran Thengil, Giovanni Pecci and Giuseppe E Santoro","doi":"10.1088/2058-9565/ade6a5","DOIUrl":"https://doi.org/10.1088/2058-9565/ade6a5","url":null,"abstract":"Exponentially small spectral gaps are known to be the crucial bottleneck for traditional Quantum Annealing (QA) based on interpolating between two Hamiltonians, a simple driving term and the complex problem to be solved, with a linear schedule in time. One of the simplest models exhibiting exponentially small spectral gaps is a ferromagnetic Ising ring with a single antiferromagnetic bond introducing frustration. Previous studies of this model have explored continuous-time diabatic QA, where optimized non-adiabatic annealing schedules provided good solutions, avoiding exponentially large annealing times. In our work, we move to a digital framework of Variational Quantum Algorithms, and present two main results: (1) we show that the model is digitally controllable with a scaling of resources that grows quadratically with the system size, achieving the exact solution using the Quantum Approximate Optimization Algorithm; (2) We combine a technique of quantum control—the Chopped RAndom Basis method—and digitized quantum annealing to construct smooth digital schedules yielding optimal solutions with very high accuracy.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"7 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533272","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

Theoretical framework for quantum associative memories 量子联想记忆的理论框架

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-01 DOI: 10.1088/2058-9565/ade184

Adrià Labay-Mora, Eliana Fiorelli, Roberta Zambrini and Gian Luca Giorgi

{"title":"Theoretical framework for quantum associative memories","authors":"Adrià Labay-Mora, Eliana Fiorelli, Roberta Zambrini and Gian Luca Giorgi","doi":"10.1088/2058-9565/ade184","DOIUrl":"https://doi.org/10.1088/2058-9565/ade184","url":null,"abstract":"Associative memory (AM) refers to the ability to relate a memory with an input and targets the restoration of corrupted patterns. It has been intensively studied in classical physical systems, as in neural networks where an attractor dynamics settles on stable solutions. Several extensions to the quantum domain have been recently reported, displaying different features. In this work, we develop a comprehensive framework for a quantum AM (QAM) based on open quantum system dynamics, which allows us to compare existing models, identify the theoretical prerequisites for performing AM tasks, and extend it in different forms. The map that achieves an exponential increase in the number of stored patterns with respect to classical systems is derived. We establish the crucial role of symmetries and dissipation in the operation of QAM. Our theoretical analysis demonstrates the feasibility of addressing both quantum and classical patterns, orthogonal and non-orthogonal memories, stationary and metastable operating regimes, and measurement-based outputs. Finally, this opens up new avenues for practical applications in quantum computing and machine learning, such as quantum error correction or quantum memories.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"10 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532959","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

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-07-01 DOI: 10.1088/2058-9565/ade7ad

Roberto Flórez-Ablan, Marco Roth and Jan Schnabel

{"title":"On the similarity of bandwidth-tuned quantum kernels and classical kernels","authors":"Roberto Flórez-Ablan, Marco Roth and Jan Schnabel","doi":"10.1088/2058-9565/ade7ad","DOIUrl":"https://doi.org/10.1088/2058-9565/ade7ad","url":null,"abstract":"Quantum kernels (QKs) are widely used in quantum machine learning applications; yet, their potential to surpass classical machine learning methods on classical datasets remains uncertain. This limitation can be attributed to the exponential concentration phenomenon, which can impair generalization. A common strategy to alleviate this is bandwidth tuning, which involves rescaling data points in the quantum model to improve generalization. In this work, we numerically demonstrate that optimal bandwidth tuning results in QKs that closely resemble radial basis function (RBF) kernels, leading to a lack of quantum advantage over classical methods. Moreover, we reveal that the size of optimal bandwidth tuning parameters further simplifies QKs, causing them to behave like polynomial kernels, corresponding to a low-order Taylor approximation of a RBF kernel. We thoroughly investigate this for fidelity quantum kernels and projected quantum kernels using various data encoding circuits across several classification datasets. We provide numerical evidence and derive a simple analytical model that elucidates how bandwidth tuning influences key quantities in classification tasks. Overall, our findings shed light on the mechanisms that render QK methods classically tractable.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"49 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533271","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