Quantum Science and Technology最新文献

Unlocking early fault-tolerant quantum computing with mitigated magic dilution 通过减轻魔法稀释来解锁早期容错量子计算

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-16 DOI: 10.1088/2058-9565/ae0aef

Surabhi Luthra, Alexandra E Moylett, Dan E Browne and Earl T Campbell

{"title":"Unlocking early fault-tolerant quantum computing with mitigated magic dilution","authors":"Surabhi Luthra, Alexandra E Moylett, Dan E Browne and Earl T Campbell","doi":"10.1088/2058-9565/ae0aef","DOIUrl":"https://doi.org/10.1088/2058-9565/ae0aef","url":null,"abstract":"As quantum computing progresses towards the early fault-tolerant regime, quantum error correction will play a crucial role in protecting qubits and enabling logical Clifford operations. However, the number of logical qubits will initially remain limited, posing challenges for resource-intensive tasks like magic state distillation. It is therefore essential to develop efficient methods for implementing non-Clifford operations, such as small-angle rotations, to maximise the computational capabilities of devices within these constraints. In this work, we introduce mitigated magic dilution (MMD) as an approach to synthesise small-angle rotations by employing quantum error mitigation techniques to sample logical Clifford circuits given noisy encoded magic states. We explore the utility of our approach for the simulation of the 2D Fermi–Hubbard model. We identify evolution time regimes where MMD outperforms state-of-the-art synthesis techniques in the number of noisy encoded magic states required for square lattices up to size . Moreover, we demonstrate that our method can provide a practical advantage that is quantified by a better-than-quadratic improvement in the resource requirements for small-angle rotations over classical simulators. This work paves the way for early fault-tolerant demonstrations on devices supporting millions of quantum operations, the so-called MegaQuOp regime.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"342 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311116","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 speed-up of quantum emitter detection via quantum interference 量子干涉探测量子发射体的大加速

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-16 DOI: 10.1088/2058-9565/ae0e4f

Warwick P Bowen

{"title":"Large speed-up of quantum emitter detection via quantum interference","authors":"Warwick P Bowen","doi":"10.1088/2058-9565/ae0e4f","DOIUrl":"https://doi.org/10.1088/2058-9565/ae0e4f","url":null,"abstract":"Quantum emitters are a key resource in quantum technologies, microscopy, and other applications. The ability to rapidly detect them is useful both for quality control in engineered emitter arrays and for high-contrast imaging of naturally occurring emitters. Using full photon-counting statistics and optimal Bayesian hypothesis testing, we show that extended Hong–Ou–Mandel (HOM) interference between quantum emission and a coherent field enables orders-of-magnitude speed-ups in emitter detection under realistic noise and loss. Strikingly, the performance advantage improves as loss and background noise increase, and persists for incoherent emission. Taken together with prior demonstrations of extended HOM interference, this suggest that substantial performance gains are achievable with current technology under realistic, non-ideal conditions. This offers a new approach to fast, low-intensity imaging and for emitter characterization in large-scale quantum systems. Fundamentally, the discovery that quantum interference and measurements, used together, are more robust to both loss and noise than standard measurement techniques opens the possibility of broad applications across quantum metrology.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"1 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145311117","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

Preconditioned block encodings for quantum linear systems 量子线性系统的预条件分组编码

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-15 DOI: 10.1088/2058-9565/ae0f4b

Leigh Lapworth and Christoph Sünderhauf

{"title":"Preconditioned block encodings for quantum linear systems","authors":"Leigh Lapworth and Christoph Sünderhauf","doi":"10.1088/2058-9565/ae0f4b","DOIUrl":"https://doi.org/10.1088/2058-9565/ae0f4b","url":null,"abstract":"Quantum linear system solvers like the quantum singular value transformation (QSVT) require a block encoding of the system matrix A within a unitary operator UA. Unfortunately, block encoding often results in significant subnormalisation and increase in the matrix’s effective condition number κ, affecting the efficiency of solvers. Matrix preconditioning is a well-established classical technique to reduce κ by multiplying A by a preconditioner P. Here, we study quantum preconditioning for block encodings. We consider four preconditioners and two encoding approaches: (a) separately encoding A and its preconditioner P, followed by quantum multiplication, and (b) classically multiplying A and P before encoding the product in UPA. Their impact on subnormalisation factors and condition number κ are analysed using practical matrices from computational fluid dynamics (CFD). Our results show that (a) quantum multiplication introduces excessive subnormalisation factors, negating improvements in κ. We study preamplified quantum multiplication to reduce subnormalisation. Conversely, we see that (b) encoding of the classical product can significantly improve the effective condition number using the sparse approximate inverse preconditioner with infill. Further, we introduce a new matrix filtering technique that reduces the circuit depth without adversely affecting the matrix solution. We apply these methods to reduce the number of QSVT phase factors by a factor of 25 for an example CFD matrix of size 1024 × 1024.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"44 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145295897","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

Iterative quantum optimization of spin glass problems with rapidly oscillating transverse fields 具有快速振荡横向场的自旋玻璃问题的迭代量子优化

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-15 DOI: 10.1088/2058-9565/ae0f4d

Brandon Barton, Jacob Sagal, Sean Feeney, George Grattan, Pratik Patnaik, Vadim Oganesyan, Lincoln D Carr and Eliot Kapit

{"title":"Iterative quantum optimization of spin glass problems with rapidly oscillating transverse fields","authors":"Brandon Barton, Jacob Sagal, Sean Feeney, George Grattan, Pratik Patnaik, Vadim Oganesyan, Lincoln D Carr and Eliot Kapit","doi":"10.1088/2058-9565/ae0f4d","DOIUrl":"https://doi.org/10.1088/2058-9565/ae0f4d","url":null,"abstract":"In this work, we introduce a new iterative quantum algorithm, called Iterative Symphonic Tunneling for Satisfiability problems (IST-SAT), which solves quantum spin glass optimization problems using high-frequency oscillating transverse fields. IST-SAT operates as a sequence of iterations, in which bitstrings returned from one iteration are used to set spin-dependent phases in oscillating transverse fields in the next iteration. Over several iterations, the novel mechanism of the algorithm steers the system toward the problem ground state. We benchmark IST-SAT on sets of hard MAX-3-XORSAT problem instances with exact state vector simulation, and report polynomial speedups over Trotterized adiabatic quantum computation and the best known semi-greedy classical algorithm. When IST-SAT is seeded with a sufficiently good initial approximation, the algorithm converges to exact solution(s) in a polynomial number of iterations. Our numerical results identify a critical Hamming radius, or quality of initial approximation, where the time-to-solution crosses from exponential to polynomial scaling in problem size. This work proposes IST-SAT a new quantum algorithm, which improves upon solutions obtained from initial classical or quantum optimization algorithms. The steering mechanism we introduce through IST-SAT presents a new path toward achieving quantum advantage in optimization.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"9 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145295898","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

Accelerating the drive towards energy-efficient generative AI with quantum computing algorithms 利用量子计算算法加速推动节能生成人工智能

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-14 DOI: 10.1088/2058-9565/ae0eac

Frederik F Flöther, Jan Mikolon and Maria Longobardi

引用次数: 0

Fundamental limits and experimental implementation of dispersive quantum thermometry 色散量子测温的基本限制与实验实现

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-14 DOI: 10.1088/2058-9565/ae0f4e

Daniel Y Akamatsu, Lucas Ferreira R de Moura, Gabriella G Damas, Gentil D de Moraes Neto, Victor Montenegro and Norton G de Almeida

{"title":"Fundamental limits and experimental implementation of dispersive quantum thermometry","authors":"Daniel Y Akamatsu, Lucas Ferreira R de Moura, Gabriella G Damas, Gentil D de Moraes Neto, Victor Montenegro and Norton G de Almeida","doi":"10.1088/2058-9565/ae0f4e","DOIUrl":"https://doi.org/10.1088/2058-9565/ae0f4e","url":null,"abstract":"Temperature estimation, known as thermometry, is a critical sensing task for physical systems operating in the quantum regime. Indeed, thermal fluctuations can significantly degrade quantum coherence. Therefore, accurately determining the system’s operating temperature is a crucial first step toward distinguishing thermal noise from other sources of decoherence. In this work, we estimate the unknown temperature of a collection of identical and independent two-level atoms dispersively probed by a single-mode quantized electromagnetic field. In contrast to previous works, we present an analytical sensing analysis demonstrating that the joint atom-field evolution—without any assumptions or approximations—can achieve, at best, the standard quantum limit of precision concerning the number of field excitations. To investigate our analysis further, we propose and implement our thermometry scheme on a nonlinear Mach–Zehnder interferometer, which we realize through quantum digital simulation. Our proposal is highly flexible regarding atomic state preparation, allowing the initialization of atomic ensembles with positive and effective negative temperatures. This makes our proposal a promising and versatile testbed for benchmarking thermometric capabilities in current quantum simulators.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"53 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145289222","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

Optimizing the quantum interference between single photons and local oscillator with photon correlations 利用光子相关优化单光子与本振之间的量子干涉

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-14 DOI: 10.1088/2058-9565/ae0a7a

Hubert Lam, Juan R Álvarez, Petr Steindl, Ilse Maillette de Buy Wenniger, Stephen Wein, Anton Pishchagin, Thi Huong Au, Sebastien Boissier, Aristide Lemaître, Wolfgang Löffler, Nadia Belabas, Dario A Fioretto and Pascale Senellart

{"title":"Optimizing the quantum interference between single photons and local oscillator with photon correlations","authors":"Hubert Lam, Juan R Álvarez, Petr Steindl, Ilse Maillette de Buy Wenniger, Stephen Wein, Anton Pishchagin, Thi Huong Au, Sebastien Boissier, Aristide Lemaître, Wolfgang Löffler, Nadia Belabas, Dario A Fioretto and Pascale Senellart","doi":"10.1088/2058-9565/ae0a7a","DOIUrl":"https://doi.org/10.1088/2058-9565/ae0a7a","url":null,"abstract":"The quantum interference between a coherent state and a single photon is an important tool in continuous variable optical quantum technologies to characterize and engineer non-Gaussian quantum states. Semiconductor quantum dots (QDs), which have recently emerged as a key platform for efficient single-photon generation, could become interesting assets in this context. An essential parameter for interfering single photons and classical fields is the mean wavepacket overlap between both fields. Here, we report on two homodyne photon-correlation techniques enabling the precise measurement of the overlap between a single photon generated by a QD-cavity device and pulsed laser light. The different statistics of interfering fields lead to specific signatures of the quantum interference on the photon correlations at the output of the interfering beam splitter. We compare the behavior of maximized overlap, measuring either the Hong–Ou–Mandel visibility between both outputs or the photon bunching at a single output. Through careful tailoring of the laser light in various degrees of freedom, we achieve a record overlap of with integrated solid-state sources, which evidences the very low level of noise in our integrated single-photon sources.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"218 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145289231","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

Hamiltonian quantum gates-energetic advantage from entangleability 哈密顿量子门——纠缠性带来的能量优势

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-13 DOI: 10.1088/2058-9565/ae0daf

Josey Stevens and Sebastian Deffner

引用次数: 0

Prospects for quantum process tomography at high energies 高能量子过程层析成像的前景

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-12 DOI: 10.1088/2058-9565/ae0af1

Clelia Altomonte, Alan J Barr, Michał Eckstein, Paweł Horodecki and Kazuki Sakurai

引用次数: 0

Multi-mode cooling of a Bose–Einstein condensate with linear quantum feedback 具有线性量子反馈的玻色-爱因斯坦凝聚体的多模冷却

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-10-09 DOI: 10.1088/2058-9565/ae0a7c

Zain Mehdi, Matthew L Goh, Matthew J Blacker, Joseph J Hope and Stuart S Szigeti

{"title":"Multi-mode cooling of a Bose–Einstein condensate with linear quantum feedback","authors":"Zain Mehdi, Matthew L Goh, Matthew J Blacker, Joseph J Hope and Stuart S Szigeti","doi":"10.1088/2058-9565/ae0a7c","DOIUrl":"https://doi.org/10.1088/2058-9565/ae0a7c","url":null,"abstract":"We theoretically investigate measurement-based feedback control over the motional degrees of freedom of an oblate quasi-2D atomic Bose–Einstein condensate (BEC) subject to continuous density monitoring. We develop a linear-quadratic-Gaussian model that describes the multi-mode dynamics of the condensate’s collective excitations under continuous measurement and control. Crucially, the multi-mode cold-damping feedback control we consider uses a realistic state-estimation scheme that does not rely upon a particular model of the atomic dynamics. We present analytical results showing that collective excitations can be cooled to below single-phonon average occupation (ground-state cooling) across a broad parameter regime, and identify the conditions under which the lowest steady-state phonon occupation is asymptotically achieved. Further, we develop multi-objective optimization methods that explore the trade-off between cooling speed and the final energy of the cloud, and provide numerical simulations demonstrating the ground-state cooling of the lowest ten motional modes above the condensate ground state. Our investigation provides concrete guidance on the feedback control design and parameters needed to experimentally realize a feedback-cooled BEC.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"122 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145255700","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