Quantum最新文献 - Book学术

Asymptotically good bosonic Fock state codes 渐近良好玻色子Fock态码

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-20 DOI: 10.22331/q-2026-10-20-2240

Dor Elimelech, Arda Aydin, Alexander Barg

{"title":"Asymptotically good bosonic Fock state codes","authors":"Dor Elimelech, Arda Aydin, Alexander Barg","doi":"10.22331/q-2026-10-20-2240","DOIUrl":"https://doi.org/10.22331/q-2026-10-20-2240","url":null,"abstract":"We study the error-correction properties of multi-mode Fock-state codes under amplitude-damping (AD) noise, focusing on the asymptotic regime in which the total excitation of the code states grows without limit and the number of photon losses induced by the noise scales linearly with it. In this setting, existing code families, which correct only sublinearly many photon losses, do not protect against amplitude-damping (AD) noise with a constant loss parameter. As our main result, we address this gap by constructing asymptotically good Fock-state codes relying on random classical codes in the discrete simplex. Unlike many standard constructions of random quantum codes, our construction introduces randomness through the underlying classical indexing structure. Randomization also enables another desirable feature: bounded per-mode occupancy, which limits the number of photons in any individual mode and thereby increases the coherence lifetime of the code states. Finally, via a relation between Fock-state codes and permutation-invariant codes, our results also yield asymptotically good families of qudit permutation-invariant codes as well as codes in monolithic nuclear state spaces.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"46 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221410","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

Reliable Entropy Estimation from Observed Statistics for Device-Independent Quantum Cryptography 基于观测统计量的可靠熵估计与设备无关的量子密码

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-20 DOI: 10.22331/q-2026-10-20-2238

Gereon KoÃmann, RenÃ© Schwonnek

引用次数: 0

Interactive proofs for verifying (quantum) learning and testing 验证（量子）学习和测试的交互式证明

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-20 DOI: 10.22331/q-2026-10-20-2239

Matthias C. Caro, Jens Eisert, Marcel Hinsche, Marios Ioannou, Alexander Nietner, Ryan Sweke

{"title":"Interactive proofs for verifying (quantum) learning and testing","authors":"Matthias C. Caro, Jens Eisert, Marcel Hinsche, Marios Ioannou, Alexander Nietner, Ryan Sweke","doi":"10.22331/q-2026-10-20-2239","DOIUrl":"https://doi.org/10.22331/q-2026-10-20-2239","url":null,"abstract":"We consider the problem of testing and learning from data in the presence of resource constraints, such as limited memory or weak data access, which place limitations on the efficiency and feasibility of testing or learning. In particular, we ask the following question: Could a resource-constrained learner/tester use interaction with a resource-unconstrained but untrusted party to solve a learning or testing problem more efficiently than they could without such an interaction? In this work, we answer this question both abstractly and for concrete problems, in two complementary ways: For a wide variety of scenarios, we prove that a resource-constrained learner cannot gain any advantage through classical interaction with an untrusted prover. As a special case, we show that for the vast majority of testing and learning problems in which quantum memory is a meaningful resource, a memory-constrained quantum algorithm cannot overcome its limitations via classical communication with a memory-unconstrained quantum prover. In contrast, when quantum communication is allowed, we construct a variety of interactive proof protocols, for specific learning and testing problems, which allow memory-constrained quantum verifiers to gain significant advantages through delegation to untrusted provers. These results highlight both the limitations and potential of delegating learning and testing problems to resource-rich but untrusted third parties.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"234 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221345","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

Rare Event Simulation of Quantum Error-Correcting Circuits 量子纠错电路的罕见事件模拟

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-15 DOI: 10.22331/q-2026-10-15-2237

Carolyn Mayer, Anand Ganti, Uzoma Onunkwo, Tzvetan Metodi, Benjamin Anker, Jacek Skryzalin

{"title":"Rare Event Simulation of Quantum Error-Correcting Circuits","authors":"Carolyn Mayer, Anand Ganti, Uzoma Onunkwo, Tzvetan Metodi, Benjamin Anker, Jacek Skryzalin","doi":"10.22331/q-2026-10-15-2237","DOIUrl":"https://doi.org/10.22331/q-2026-10-15-2237","url":null,"abstract":"We describe a practical approach for accessing the logical failure rates of quantum error-correcting (QEC) circuits under low physical (component) failure rate regimes. Standard Monte Carlo is often the de facto approach for studying the failure rates of quantum circuits. However, in the study of fault-tolerant error-correcting circuits, the ability to extend this approach to low physical failure rates is limited. In particular, the use of Monte Carlo to access circuits that are relatively large or have high correcting power becomes more difficult as we lower the input failure rates of the individual components (gates) in the circuit. For these reasons, many simulations studying the circuit model go no lower than end-to-end logical failure rates in the $10^{-6}$ regime.<br/>\u0000<br/> In this report, we outline an approach that borrows from earlier work by Bravyi and Vargo [6] to the more complex circuit noise model. Earlier works studied both the capacity and phenomenological noise models [6,3,5], but the work is insufficient for generating similar simulations in the circuit-noise model. To the best of our knowledge, our team is the first to develop a full prescription of the rare event simulation by splitting technique for the circuit-based noise model. We have also generated promising results that are confirmed by standard Monte Carlo simulation under an accessible regime. This work shows that we can access noise in the circuit-model prescription of quantum error-correcting code to failure rates below $10^{-20}$ regime.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"10 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149172601","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

Approach to optimal quantum transport via states over time 通过状态随时间的最佳量子输运方法

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-14 DOI: 10.22331/q-2026-10-14-2236

Matt Hoogsteder-Riera, John Calsamiglia, Andreas Winter

引用次数: 0

Quantum Walks on Arbitrary Spatial Networks with Rydberg Atoms Rydberg原子在任意空间网络上的量子行走

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-13 DOI: 10.22331/q-2026-10-13-2235

Gabriel Almeida, Raul Santos, Lara Janiurek, Yasser Omar

引用次数: 0

Sampled-Based Guided Quantum Walk: Non-variational quantum algorithm for combinatorial optimization 基于采样的引导量子行走：用于组合优化的非变分量子算法

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-13 DOI: 10.22331/q-2026-10-13-2234

Ugo Nzongani, Dylan Laplace Mermoud, Giuseppe Di Molfetta, Andrea Simonetto

{"title":"Sampled-Based Guided Quantum Walk: Non-variational quantum algorithm for combinatorial optimization","authors":"Ugo Nzongani, Dylan Laplace Mermoud, Giuseppe Di Molfetta, Andrea Simonetto","doi":"10.22331/q-2026-10-13-2234","DOIUrl":"https://doi.org/10.22331/q-2026-10-13-2234","url":null,"abstract":"We introduce SamBa-GQW, a novel quantum algorithm for solving binary combinatorial optimization problems of arbitrary degree with no use of any classical optimizer. The algorithm is based on a continuous-time quantum walk on the solution space represented as a graph. The walker explores the solution space to find its way to vertices that minimize the cost function of the optimization problem. The key novelty of our algorithm is an offline classical sampling protocol that gives information about the spectrum of the problem Hamiltonian. Then, the extracted information is used to guide the walker to high quality solutions via a quantum walk with a time-dependent hopping rate. We investigate the performance of SamBa-GQW on several quadratic problems, namely MaxCut, maximum independent set, portfolio optimization, and higher-order polynomial problems such as LABS, MAX-$k$-SAT and a quartic reformulation of the travelling salesperson problem. We empirically demonstrate that SamBa-GQW finds high quality approximate solutions on problems up to a size of $n=30$ qubits by only sampling poly($n$) states among $2^n$ possible decisions. Furthermore, SamBa-GQW compares in par with classically optimized variational approaches, such as the variational guided quantum walk and QAOA (the latter when run on deep circuits). This places Samba-GQW as a promising heuristic to tackle combinatorial problems beyond the NISQ regime.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"158 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149152625","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 algorithms for general nonlinear dynamics based on the Carleman embedding 基于Carleman嵌入的一般非线性动力学量子算法

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-08 DOI: 10.22331/q-2026-10-08-2233

David Jennings, Kamil Korzekwa, Matteo Lostaglio, Andrew T Sornborger, Yigit Subasi, Guoming Wang

{"title":"Quantum algorithms for general nonlinear dynamics based on the Carleman embedding","authors":"David Jennings, Kamil Korzekwa, Matteo Lostaglio, Andrew T Sornborger, Yigit Subasi, Guoming Wang","doi":"10.22331/q-2026-10-08-2233","DOIUrl":"https://doi.org/10.22331/q-2026-10-08-2233","url":null,"abstract":"Important nonlinear dynamics, such as those found in plasma and fluid systems, are typically hard to simulate on classical computers. Thus, if fault-tolerant quantum computers could efficiently solve such nonlinear problems, it would be a transformative change for many industries. In a recent breakthrough [Liu et al., PNAS 2021], the first efficient quantum algorithm for solving nonlinear differential equations was constructed, based on a single condition $R lt 1$, where $R$ characterizes the ratio of nonlinearity to dissipation. This result, however, is limited to the class of purely dissipative systems with negative log-norm, which excludes application to many important problems. In this work, we correct technical issues with this and other prior analysis, and substantially extend the scope of nonlinear dynamical systems that can be efficiently simulated on a quantum computer in a number of ways. Firstly, we extend the existing results from purely dissipative systems to a much broader class of stable systems, and show that every quadratic Lyapunov function for the linearized system corresponds to an independent $R$-number criterion for the convergence of the Carleman scheme. Secondly, we extend our stable system results to physically relevant settings where conserved polynomial quantities exist. Finally, we provide extensive results for the class of non-resonant systems. With this, we are able to show that efficient quantum algorithms exist for a much wider class of nonlinear systems than previously known, and prove the BQP-completeness of nonlinear oscillator problems of exponential size. In our analysis, we also obtain several results related to the Poincaré-Dulac theorem and diagonalization of the Carleman matrix, which could be of independent interest.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"9 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149123738","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

Towards local and compositional measurements in quantum field theory 量子场论中的局部测量和组分测量

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-08 DOI: 10.22331/q-2026-10-08-2232

Robert Oeckl, Adamantia Zampeli

{"title":"Towards local and compositional measurements in quantum field theory","authors":"Robert Oeckl, Adamantia Zampeli","doi":"10.22331/q-2026-10-08-2232","DOIUrl":"https://doi.org/10.22331/q-2026-10-08-2232","url":null,"abstract":"A universal framework for the joint measurement of multiple localized observables in quantum field theory satisfying spacetime locality and compositionality is still lacking. We present an approach to the problem that is based on the one hand on the positive formalism, an axiomatic framework, where it is clear from the outset that we satisfy locality and compositionality, while also having a consistent probabilistic interpretation. On the other hand, the approach is based on standard tools from quantum field theory, in particular the path integral and the Schwinger-Keldysh formalism. After an overview of the conceptual foundations we introduce the modulus-square construction as a formalization of the measurement process for the expectation value of an important class of observables including quadratic observables. We show that this construction has many of the desired properties, including positivity, locality, single measurement recovery and compositionality. We introduce a renormalization scheme for the measurement of quadratic observables that also satisfies compositionality, in contrast to previous renormalization schemes. We discuss relativistic causality, confirming that measurements in our scheme are indeed localized in the spacetime regions where the underlying observables have support.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"38 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149123735","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

Composable logical gate error in approximate quantum error correction: reexamining gate implementations in Gottesman-Kitaev-Preskill codes 近似量子纠错中的可组合逻辑门错误：重新检查Gottesman-Kitaev-Preskill码中的门实现

IF 6.4 2区物理与天体物理

Quantum Pub Date : 2026-10-08 DOI: 10.22331/q-2026-10-08-2230

Lukas Brenner, Beatriz Dias, Robert Koenig

{"title":"Composable logical gate error in approximate quantum error correction: reexamining gate implementations in Gottesman-Kitaev-Preskill codes","authors":"Lukas Brenner, Beatriz Dias, Robert Koenig","doi":"10.22331/q-2026-10-08-2230","DOIUrl":"https://doi.org/10.22331/q-2026-10-08-2230","url":null,"abstract":"Quantifying the accuracy of logical gates is paramount in approximate error correction, where perfect implementations are often unachievable with the available set of physical operations. To this end, we introduce a single scalar quantity we call the (composable) logical gate error. It captures both the deviation of the logical action from the desired target gate as well as leakage out of the code space. It is subadditive under successive application of gates, providing a simple means for analyzing circuits. We show how to bound the composable logical gate error in terms of matrix elements of physical unitaries between (approximate) logical computational basis states. In the continuous-variable context, this sidesteps the need for computing energy-bounded norms.<br/> As an example, we study the composable logical gate error for linear optics implementations of Paulis and Cliffords in approximate Gottesman-Kitaev-Preskill (GKP) codes. We find that the logical gate error for implementations of Paulis depends linearly on the squeezing parameter. This implies that their accuracy improves monotonically with the amount of squeezing. For some Cliffords, however, linear optics implementations which are exact for ideal GKP codes fail in the approximate case: they have a constant logical gate error even in the limit of infinite squeezing. This is consistent with previous results about the limitations of certain gate implementations for approximate GKP codes. It shows that findings applicable to ideal GKP codes do not always translate to the realm of physically realizable approximate GKP codes.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"30 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149123733","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