Quantum Science and Technology最新文献_第2页

Non-Markovianity in structured nonequilibrium environment: impacts on Landauer's principle and quantum batteries 结构非平衡环境中的非马尔可夫性：对兰道尔原理和量子电池的影响

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-13 DOI: 10.1088/2058-9565/aeb3ae

Xiao-Yu Chi,Qi Zhang,Yun-Jie Xia,Zhong-Xiao Man

引用次数: 0

Gate-Based Path integral Quantum Control applied to quantum chemistry 基于门的路径积分量子控制在量子化学中的应用

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-13 DOI: 10.1088/2058-9565/aeb3b1

Peyman Najafi,Aaron Villanueva,H J Kappen

{"title":"Gate-Based Path integral Quantum Control applied to quantum chemistry","authors":"Peyman Najafi,Aaron Villanueva,H J Kappen","doi":"10.1088/2058-9565/aeb3b1","DOIUrl":"https://doi.org/10.1088/2058-9565/aeb3b1","url":null,"abstract":"Abstract The Path integral Quantum Control (PiQC) algorithm was recently introduced as a new approach&#xD;for computing optimal controls in continuous-time open and closed quantum systems. In this work,&#xD;we adapt the PiQC algorithm to optimize parametrized quantum circuits and refer to this version&#xD;of PiQC as the Gate-Based PiQC (GB-PiQC) algorithm. We apply GB-PiQC and the original&#xD;continuous-time version of PiQC for ground state preparation of electronic structure problems, and&#xD;benchmark them against the Variational Quantum Eigensolver (VQE), optimized using the stan-&#xD;dard Simultaneous Perturbation Stochastic Approximation (SPSA) optimizer, on a set of standard&#xD;benchmark molecular Hamiltonians. For a fair comparison, we optimize the hyperparameters of the&#xD;algorithms for each molecule. We find that both PiQC algorithms exhibit greater robustness than&#xD;SPSA to variations in the target Hamiltonian induced by changes in interatomic distance, when&#xD;hyperparameters for both methods are fixed at values tuned near equilibrium. Furthermore, PiQC&#xD;algorithms also achieve superior performance compared to SPSA in most instances under this fixed-&#xD;hyperparameter setting, particularly at stretched interatomic distances, where the Hartree–Fock&#xD;(HF) solution becomes less accurate and its error grows relative to equilibrium","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"21 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209151","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

Grid-state deformation in a no-jump non-Hermitian bosonic dimer 无跳变非厄米玻色子二聚体中的网格态变形

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-13 DOI: 10.1088/2058-9565/aeb3b2

Blas Manuel Rodriguez-Lara,Hamed Ghaemidizicheh,Shahram Dehdashti,Andreas Hanke,Ahmed Touhami,Janis Nötzel

{"title":"Grid-state deformation in a no-jump non-Hermitian bosonic dimer","authors":"Blas Manuel Rodriguez-Lara,Hamed Ghaemidizicheh,Shahram Dehdashti,Andreas Hanke,Ahmed Touhami,Janis Nötzel","doi":"10.1088/2058-9565/aeb3b2","DOIUrl":"https://doi.org/10.1088/2058-9565/aeb3b2","url":null,"abstract":"Abstract We study the no-jump evolution of ideal grid states in a lossy bosonic dimer with differential decay. The effective non-Hermitian quadratic dynamics induces a complex symplectic flow in phase space that deforms both the primitive lattice vectors and the origin seed. The average decay rate controls common-mode attenuation, while coherent hopping and differential decay control the reduced dimer deformation. For resonant modes, the reduced displacement flow is oscillatory in the elliptic regime, linear at the exceptional point, and exponentially separating in the hyperbolic regime. Although projected lattice areas can change, the deformation comes from a determinant-one complex symplectic flow on the complexified phase space. For a Gaussian regularization of the origin seed in the resonant dimer, we derive the associated complex width matrix and show that the seed remains square-integrable and Gaussian for every positive initial width, all non-negative times, and all physical loss rates. For an initial two-mode qunaught product state, the lossless limit recovers the standard beam-splitter generation of a square GKP+ Bell pair, while the no-jump dynamics produces its non-Hermitian deformation. The full no-jump probability for a normalized finite-energy input sets the postselection cost and depends on its excitation-number distribution and the reduced dimer dynamics.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"56 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209152","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

Entanglement dynamics in a two–transmon qubit system under continuous measurement and postselection 连续测量和后选择下双激子量子比特系统的纠缠动力学

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-13 DOI: 10.1088/2058-9565/aeb3a8

Roson Nongthombam,Amarendra Kumar Sarma

{"title":"Entanglement dynamics in a two–transmon qubit system under continuous measurement and postselection","authors":"Roson Nongthombam,Amarendra Kumar Sarma","doi":"10.1088/2058-9565/aeb3a8","DOIUrl":"https://doi.org/10.1088/2058-9565/aeb3a8","url":null,"abstract":"Abstract We investigate the role of continuous measurement and postselection in the dynamics and en&#xD;tanglement of a transmon-cavity-transmon coupled system. In the dispersive regime, characterized&#xD;by a large detuning between the transmons and the cavity, the two transmons interact via virtual&#xD;excitation of the cavity, giving rise to an effective transmon-transmon coupling. In addition to this&#xD;coherent interaction, each transmon undergoes spontaneous emission, which is continuously mon&#xD;itored through independent detection channels. By incorporating realistic detector inefficiencies,&#xD;we analyze both efficient and imperfect monitoring scenarios and demonstrate that postselection&#xD;significantly slows down the decay of entanglement compared to the unmonitored case. We formu&#xD;late the stochastic master equation for the coupled system, derive the corresponding postselected&#xD;master equation, and investigate the dynamics through the Liouvillian superoperator spectrum.&#xD;In the interaction frame, we identify the emergence of an exceptional point and characterize the&#xD;associated broken and unbroken PT-symmetric phases. We show how these phases influence the&#xD;system dynamics and the corresponding entanglement behavior. Our results provide insight into&#xD;how continuous measurement and postselection affect entanglement in dissipative quantum systems,&#xD;with potential applications in quantum information processing.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"11 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149208776","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

Lie-theoretic structure of parameter gradients in variational quantum circuits 变分量子电路中参数梯度的李氏结构

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-13 DOI: 10.1088/2058-9565/aeb3aa

María-Luisa Pérez-Delgado,Roberto Casado

{"title":"Lie-theoretic structure of parameter gradients in variational quantum circuits","authors":"María-Luisa Pérez-Delgado,Roberto Casado","doi":"10.1088/2058-9565/aeb3aa","DOIUrl":"https://doi.org/10.1088/2058-9565/aeb3aa","url":null,"abstract":"Abstract Variational quantum circuits are a central paradigm of quantum machine learning and near-term quantum computing, yet their practical optimization is often limited by strongly suppressed parameter gradients. Dynamical Lie algebras provide a rigorous description of the infinitesimal directions accessible to a variational architecture, but dynamical accessibility alone does not determine the gradient signal exposed by an actual circuit parametrization. In this work, we develop a Lie-theoretic description of parameter-gradient structure that separates four successive mechanisms: dynamical accessibility, observable visibility, state-dependent activation, and local parameter realization. The optimization observable determines which accessible directions can influence the objective and how strongly they couple to it, while the quantum state selects which of these response modes are locally activated. This information is then pulled back through the circuit parametrization to recover the actual parameter gradients. The resulting construction yields an exact modal decomposition of the accessible gradient signal, a hierarchy of structural bounds, and a natural description of state averaging. An analytical single-qubit example and controlled numerical experiments validate the successive levels of the hierarchy and show that accessible Lie dimension alone is insufficient to characterize the parameter-gradient scale. The results support a mechanism-based view of variational trainability in which parameter gradients emerge from the interaction between accessible dynamics, observable coupling, quantum-state activation, and circuit parametrization.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"37 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149208774","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

Operator learning for efficient quantum computation 高效量子计算的算子学习

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-13 DOI: 10.1088/2058-9565/aeb3b0

Paul Over,Sergio Bengoechea,Leonardo Borello Busilacchi,Martin Kiffner,Thomas Rung,Alexios A Michailidis

{"title":"Operator learning for efficient quantum computation","authors":"Paul Over,Sergio Bengoechea,Leonardo Borello Busilacchi,Martin Kiffner,Thomas Rung,Alexios A Michailidis","doi":"10.1088/2058-9565/aeb3b0","DOIUrl":"https://doi.org/10.1088/2058-9565/aeb3b0","url":null,"abstract":"Abstract An efficient implementation of quantum algorithms is often hindered by the lack of efficient primitives for operators and state preparation. &#xD;This limits both the ability of near-term quantum hardware to simulate complex problems and the potential of fault-tolerant algorithms to achieve practical quantum advantage. &#xD;To address this, we propose a framework that maps discrete operators onto compact, structured quantum circuits.&#xD;The resulting variational circuits can be tailored to the connectivity and long-range interaction of the target hardware. &#xD;The learning process employs backpropagation together with a cost function that efficiently optimizes unitary operators and non-unitary --dense or sparse-- operators using only a single ancilla qubit for block encoding.&#xD;Additionally, we introduce a regularization term that reduces the approximation error.&#xD;The approach is validated for both quantum mechanical and engineering applications. &#xD;In the former case, we learn propagators that arise in native quantum problems --such as quantum simulation and quantum chemistry-- and achieve improved resource scaling in comparison to standard Suzuki--Trotter expansions.&#xD;In the latter case, we demonstrate the approach's ability to implement the second-order central finite difference approximation of the Laplace operator --relevant for solving partial differential equations-- while improving upon current error metrics.&#xD;The final example deals with learning a dense, non-unitary operator that arises in the analysis of inviscid potential flow around an airfoil. &#xD;These results motivate the extension of the framework to a broader class of operator-synthesis problems beyond the prototypical engineering and quantum applications considered here.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"11 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149208775","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

Time Crystals on Quantum Devices 量子器件上的时间晶体

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-09 DOI: 10.1088/2058-9565/aeb255

Gonzalo Camacho,Benedikt Fauseweh

引用次数: 0

Calculating strongly correlated ground states from the non-Markovian dissipative dynamics of Gaussian fermions 从高斯费米子的非马尔可夫耗散动力学计算强相关基态

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-09 DOI: 10.1088/2058-9565/aeb256

Giuliano Chiriacò

{"title":"Calculating strongly correlated ground states from the non-Markovian dissipative dynamics of Gaussian fermions","authors":"Giuliano Chiriacò","doi":"10.1088/2058-9565/aeb256","DOIUrl":"https://doi.org/10.1088/2058-9565/aeb256","url":null,"abstract":"Abstract We introduce a mapping between the ground state of interacting fermionic Hamiltonians and the non-equilibrium steady state of a purely dissipative open quantum system. Within the framework of third quantization, we map the Fermi-Hubbard Hamiltonian onto Lindblad jump operators acting on Majorana fermions. Remarkably, both hopping and interaction terms map onto jump operators that preserve the Gaussianity of Majorana fermions along individual quantum trajectories. As a result, the dynamics can be unravelled and each trajectory can be simulated efficiently using only two-point correlation functions, with a computational cost that scales polynomially with system size. We further show that finite particle number requires negative dissipative rates, leading to an intrinsically non-Markovian dynamics. The corresponding trajectory unravelling involves both positive and negative stochastic weights and exhibits a sign problem and large fluctuations, so that convergence requires an exponentially large number of trajectories. The overall computational cost remains exponential in system size despite the efficient Gaussian representation of individual trajectories, but is crucially dependent on the computational complexity of the non-Markovian unravelling, motivating further studies on the efficiency of such unravellings.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"69 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150273","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 Mpemba effect: anomalous relaxation of multi-spin system under local noise 量子Mpemba效应：局部噪声下多自旋系统的反常弛豫

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-07 DOI: 10.1088/2058-9565/aeb157

晓旭宁,Zhendong Wei,Wei-Bin Yan,Zhong-Xiao Man,Yun-Jie Xia,Zhang Ying-Jie,Qing-yu Cai

{"title":"Quantum Mpemba effect: anomalous relaxation of multi-spin system under local noise","authors":"晓旭宁,Zhendong Wei,Wei-Bin Yan,Zhong-Xiao Man,Yun-Jie Xia,Zhang Ying-Jie,Qing-yu Cai","doi":"10.1088/2058-9565/aeb157","DOIUrl":"https://doi.org/10.1088/2058-9565/aeb157","url":null,"abstract":"Abstract The Quantum Mpemba effect (QMPE) is characterized by a state initially farther from equilibrium relaxing faster than one closer to it. In this work, we investigate the QMPE in an open central-spin model, and examine whether the QMPE emerges when the spins' system is subjected to their independent noisy environment for different initial states. Simultaneously, we analyze the influence of the noisy environment on the dynamics and demonstrate that tuning local noise strengths can induce the QMPE. Furthermore, we systematically explore finite-size effects by varying the number of peripheral spins. In addition, we investigate the Pontus Mpemba effect within the same framework, demonstrating that an auxiliary decohering environment can accelerate the approach to stationarity. To observe the effect, we select the trace distance, energy, and l 1 -norm coherence as observables. By combining initialstate engineering (global rotation operations) with the modulation of the noisy environment, we clearly reveal the physical mechanisms for inducing and controlling the QMPE in this model. Our results show that both rotating the initial states and applying non-uniform local noises can alter the relaxation rate ordering among different states, leading to crossings in the evolution curves of various physical quantities, that is, the realization of the QMPE. This finding provides a new perspective for manipulating anomalous relaxation behavior in the quantum many-body system and open quantum system.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"22 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150272","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

Adaptive Qubit Freezing Enables Robust Graph Partitioning for Divide-and-Conquer QAOA 自适应量子位冻结实现分而治之QAOA的鲁棒图划分

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2026-10-06 DOI: 10.1088/2058-9565/aeb0c5

SOKEA SANG,Leanghok Hour,Dongmin Kim,Youngsun Han

{"title":"Adaptive Qubit Freezing Enables Robust Graph Partitioning for Divide-and-Conquer QAOA","authors":"SOKEA SANG,Leanghok Hour,Dongmin Kim,Youngsun Han","doi":"10.1088/2058-9565/aeb0c5","DOIUrl":"https://doi.org/10.1088/2058-9565/aeb0c5","url":null,"abstract":"Abstract Separator-based divide-and-conquer QAOA can address graphs wider than the qubit capacity of one circuit, meaning the number of physical qubits usable by that circuit, but the Large Graph Partitioner (LGP) in DC-QAOA aborts when no small vertex separator exists. We introduce Frozen Large Graph Partitioning (FrozenLGP), a three-phase extension of this specific pipeline. It first runs standard LGP (Phase 1); after failure, it freezes a minimum node cut of each selected residual graph, conditional on the first budget-feasible separator (Phase 2); and it uses a deterministic width-feasible split as Coverage-Preserving Partitioning (CPP) for a final fallback (Phase 3). For a fixed frozen spin assignment, removed Ising couplings are folded exactly into local fields; assignment selection, QAOA, truncated reconstruction, and fallback ranking remain approximate. On the pooled high-connectivity partition benchmarks (n ≤ 1000), the scalable driver achieves 89.8% separator-based coverage without the CPP fallback at freeze budget B_f = 3, compared with 4.6% for standard LGP alone. In the 100-instance end-to-end benchmark, FrozenLGP's Phase 2 increases coverage without CPP from 76 to 91 instances in the selected best-restart outcomes. The deterministic CPP fallback handles the remaining nine. CPP-inclusive coverage is 100%, including all tested partitioning instances up to 10^4 vertices. This is a termination guarantee, not a measure of freezing-based recovery. When Phase 1 succeeds, both methods follow identical seeded circuit paths and attain identical approximation ratios. Compared with QAOA-in-QAOA, FrozenLGP achieves higher mean approximation ratios at each measured size, at the cost of more invoked subcircuit solves and greater aggregate quantum work. Under two simulated noise channels, the coverage extension persists while the reported output distributions of every method degrade under the stronger channel. In simulation, these results support FrozenLGP as a topology-robust front end for separator-based divide-and-conquer QAOA.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"92 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149089754","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