Quantum Science and Technology最新文献_第10页

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-25 DOI: 10.1088/2058-9565/adc14f

Renato M S Farias, Raghavendra D Peddinti, Ingo Roth and Leandro Aolita

{"title":"Robust ultra-shallow shadows","authors":"Renato M S Farias, Raghavendra D Peddinti, Ingo Roth and Leandro Aolita","doi":"10.1088/2058-9565/adc14f","DOIUrl":"https://doi.org/10.1088/2058-9565/adc14f","url":null,"abstract":"We present a robust shadow estimation protocol for wide classes of low-depth measurement circuits that mitigates noise as long as the effective measurement map including noise is locally unitarily invariant. This is in practice an excellent approximation, encompassing for instance the case of ideal single-qubit Clifford gates composing the first circuit layer of an otherwise arbitrary circuit architecture and even non-Markovian, gate-dependent noise in the rest of the circuit. We argue that for weakly-correlated local noise, the measurement channel has an efficient matrix-product representation, and show how to estimate this directly from experimental data using tensor-network tools, eliminating the need for analytical or numeric calculations. We illustrate the relevance of our method with both numerics and proof-of-principle experiments on an IBM Quantum device. Numerically, we show that unmitigated shallow shadows with noisy circuits become more biased as the depth increases. In contrast, using the same number of samples, robust ultra-shallow shadows become more precise with increasing depth for relevant parameter regimes. The gain in sample efficiency is still limited by the noise per gate, resulting in an optimal circuit depth per noise level. Experimentally, we observe improved precision in two simple fidelity estimation tasks using five-qubit circuits with up to two layers of entangling gates, by about an order of magnitude. Under the practical constraints of current and near-term noisy quantum devices, our method maximally realizes the potential of shadow estimation with global rotations and identifies its fundamental limitations in the presence of noise.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"57 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695439","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

Lossy compression based on polar codes for high throughput information reconciliation in CV-QKD systems 基于极性码的有损压缩在CV-QKD系统中的高通量信息协调

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-20 DOI: 10.1088/2058-9565/adbf41

Yameng Liu, Xue-Qin Jiang, Jisheng Dai, Han Hai and Peng Huang

{"title":"Lossy compression based on polar codes for high throughput information reconciliation in CV-QKD systems","authors":"Yameng Liu, Xue-Qin Jiang, Jisheng Dai, Han Hai and Peng Huang","doi":"10.1088/2058-9565/adbf41","DOIUrl":"https://doi.org/10.1088/2058-9565/adbf41","url":null,"abstract":"Information reconciliation (IR) is a crucial component in the post-processing stage of continuous-variable quantum key distribution (CV-QKD) systems. However, the requirement to process a large amount of information in IR has become the bottleneck of realizing high-throughput CV-QKD systems, and the phenomenon of classical channel overloads appears. To solve these issues, we first propose a lossy compression scheme based on polar codes for the Gaussian sequences, and then propose an efficient IR protocol by combining such a lossy compression. By compressing the Gaussian sequences obtained by Alice and Bob, the new proposed protocol reduces the amount of information to be processed in IR, effectively breaking the bottleneck of realizing high-throughput CV-QKD systems. Additionally, it reduces the information Alice and Bob need to transmit over classical channels, easing the classical channel load. The theoretical analysis conducted on the compression ratio of the protocol and throughput offers valuable guidance for IR. Simulations confirmed that the proposed protocol can achieve higher throughput over the other polar-code-based IR protocols.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"118 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143661280","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

Optimal control of spin qudits subject to decoherence using amplitude-and-frequency-constrained pulses 利用幅度和频率约束脉冲对受退相干影响的自旋量子的最优控制

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-20 DOI: 10.1088/2058-9565/adbf44

Alonso Hernández-Antón, Fernando Luis and Alberto Castro

{"title":"Optimal control of spin qudits subject to decoherence using amplitude-and-frequency-constrained pulses","authors":"Alonso Hernández-Antón, Fernando Luis and Alberto Castro","doi":"10.1088/2058-9565/adbf44","DOIUrl":"https://doi.org/10.1088/2058-9565/adbf44","url":null,"abstract":"Quantum optimal control theory (QOCT) can be used to design the shape of electromagnetic pulses that implement operations on quantum devices. By using non-trivially shaped waveforms, gates can be made significantly faster than those built by concatenating monochromatic pulses. Recently, we applied this idea to the control of molecular spin qudits modeled with Schrödinger’s equation and showed it can speed up operations, helping mitigate the effects of decoherence (Castro et al 2022 Phys. Rev. Appl.17 064028). However, short gate times require large optimal pulse amplitudes, which may not be experimentally accessible. Introducing bounds to the amplitudes then unavoidably leads to longer operation times, for which decoherence can no longer be neglected. Here, we study how to improve this procedure by applying QOCT on top of Lindblad’s equation, to design control pulses accounting for decoherence already in the optimization process. We define the control signal in terms of generic parameters, which permits the introduction of bounds and constraints. This is convenient, as amplitude and frequency limitations are inherent to waveform generators. The pulses that we obtain consistently enhance operation fidelities compared to those achieved with the optimization based on Schrödinger’s equation, demonstrating the flexibility and robustness of our method. The improvement is larger the shorter the spin coherence time T2.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"70 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143661268","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

Integrating quantum algorithms into classical frameworks: a predictor–corrector approach using HHL 将量子算法集成到经典框架中：使用HHL的预测校正方法

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-18 DOI: 10.1088/2058-9565/adbb14

Omer Rathore, Alastair Basden, Nicholas Chancellor and Halim Kusumaatmaja

{"title":"Integrating quantum algorithms into classical frameworks: a predictor–corrector approach using HHL","authors":"Omer Rathore, Alastair Basden, Nicholas Chancellor and Halim Kusumaatmaja","doi":"10.1088/2058-9565/adbb14","DOIUrl":"https://doi.org/10.1088/2058-9565/adbb14","url":null,"abstract":"The application of quantum algorithms to classical problems is generally accompanied by significant bottlenecks when transferring data between quantum and classical states, often negating any intrinsic quantum advantage. Here we address this challenge for a well-known algorithm for linear systems of equations, originally proposed by Harrow, Hassidim and Lloyd (HHL), by adapting it into a predictor–corrector instead of a direct solver. Rather than seeking the solution at the next time step, the goal now becomes determining the change between time steps. This strategy enables the intelligent omission of computationally costly steps commonly found in many classical algorithms, while simultaneously mitigating the notorious readout problems associated with extracting solutions from a quantum state. Random or regularly performed skips instead lead to simulation failure. We demonstrate that our methodology secures a useful polynomial advantage over a conventional application of the HHL algorithm. The practicality and versatility of the approach are illustrated through applications in various fields such as smoothed particle hydrodynamics, plasma simulations, and reactive flow configurations. Moreover, the proposed algorithm is well suited to run asynchronously on future heterogeneous hardware infrastructures and can effectively leverage the synergistic strengths of classical as well as quantum compute resources.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"90 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143641082","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

Two-photon interference at a telecom wavelength for quantum networking 量子网络中电信波长的双光子干涉

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-18 DOI: 10.1088/2058-9565/adbb87

Mathis Cohen, Laurent Labonté, Romain Dalidet, Sébastien Tanzilli and Anthony Martin

引用次数: 0

Scalable quantum eraser with superconducting integrated circuits 具有超导集成电路的可伸缩量子擦除器

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-18 DOI: 10.1088/2058-9565/adbded

Ciro Micheletti Diniz, Celso J Villas-Boas and Alan C Santos

引用次数: 0

Transfer learning in predicting quantum many-body dynamics: from physical observables to entanglement entropy 预测量子多体动力学的迁移学习：从物理观测到纠缠熵

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-17 DOI: 10.1088/2058-9565/adbd6d

Philipp Schmidt, Florian Marquardt and Naeimeh Mohseni

{"title":"Transfer learning in predicting quantum many-body dynamics: from physical observables to entanglement entropy","authors":"Philipp Schmidt, Florian Marquardt and Naeimeh Mohseni","doi":"10.1088/2058-9565/adbd6d","DOIUrl":"https://doi.org/10.1088/2058-9565/adbd6d","url":null,"abstract":"Deep neural networks have demonstrated remarkable efficacy in extracting meaningful representations from complex datasets. This has propelled representation learning as a compelling area of research across diverse fields. One interesting open question is how beneficial representation learning can be for quantum many-body physics, with its notoriously high-dimensional state space. In this work, we showcase the capacity of a neural network that was trained on a subset of physical observables of a many-body system to partially acquire an implicit representation of the wave function. We illustrate this by demonstrating the effectiveness of reusing the representation learned by the neural network to enhance the learning process of another quantity derived from the quantum state. In particular, we focus on how the pre-trained neural network can enhance the learning of entanglement entropy. This is of particular interest as directly measuring the entanglement in a many-body system is very challenging, while a subset of physical observables can be easily measured in experiments. We show the pre-trained neural network learns the dynamics of entropy with fewer resources and higher precision in comparison with direct training on the entanglement entropy.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"14 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143635263","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

Measurement schemes for quantum linear equation solvers 量子线性方程解算器的测量方案

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-14 DOI: 10.1088/2058-9565/adbcd0

Andrew Patterson and Leigh Lapworth

{"title":"Measurement schemes for quantum linear equation solvers","authors":"Andrew Patterson and Leigh Lapworth","doi":"10.1088/2058-9565/adbcd0","DOIUrl":"https://doi.org/10.1088/2058-9565/adbcd0","url":null,"abstract":"Solving computational fluid dynamics (CFD) problems requires the inversion of a linear system of equations, which can be done using a quantum algorithm for matrix inversion (Gilyén et al 2019 Proc. 51st Annual ACM SIGACT Symp. on Theory of Computing 193–204). However, the number of shots required to measure the output of the system can be prohibitive and remove any advantage obtained by quantum computing. In this work we propose a scheme for measuring the output of a quantum singular value transform (QSVT) matrix inversion algorithm specifically for the CFD use case. We use a quantum signal processing based amplitude estimation algorithm (Rall and Fuller 2023 Quantum7 937) and show how it can be combined with the QSVT matrix inversion algorithm. We perform a detailed resource estimation of the amount of computational resources required for a single iteration of amplitude estimation, and compare the costs of amplitude estimation with the cost of not doing amplitude estimation and measuring the whole wavefunction. We also propose a measurement scheme to reduce the number of amplitudes measured in the CFD example by focussing on large amplitudes only. We simulate the whole CFD loop, finding that thus measuring only a small number of the total amplitudes in the output vector still results in an acceptable level of overall error.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"19 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143618785","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

Dynamical invariant based shortcut to equilibration in open quantum systems 开放量子系统中基于动态不变量的平衡捷径

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-13 DOI: 10.1088/2058-9565/adbcce

Mohamed Boubakour, Shimpei Endo, Thomás Fogarty and Thomas Busch

引用次数: 0

Photon-mediated dipole–dipole interactions as a resource for quantum science and technology in cold atoms 光子介导的偶极-偶极相互作用作为冷原子量子科学和技术的资源

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-03-10 DOI: 10.1088/2058-9565/adbb86

H H Jen

{"title":"Photon-mediated dipole–dipole interactions as a resource for quantum science and technology in cold atoms","authors":"H H Jen","doi":"10.1088/2058-9565/adbb86","DOIUrl":"https://doi.org/10.1088/2058-9565/adbb86","url":null,"abstract":"Photon-mediated dipole–dipole interactions arise from atom-light interactions, which are universal and prevalent in a wide range of open quantum systems. This pairwise and long-range spin-exchange interaction results from multiple light scattering among the atoms. A recent surge of interests and progresses in both experiments and theories promises this core mechanism of collective interactions as a resource to study quantum science and to envision next-generation applications in quantum technology. Here we summarize recent developments in both theories and experiments, where we introduce several central theoretical approaches and focus on cooperative light scattering from small sample of free-space atoms, an atom-waveguide coupled interface that hosts the waveguide QED, and topological quantum optical platforms. The aim of this review is to manifest the essential and distinct features of collective dynamics induced by resonant dipole–dipole interactions and to reveal unprecedented opportunities in enhancing the performance or offering new applications in light manipulations, quantum metrology, quantum computations, and light harvesting innovations.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"38 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143582687","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