Quantum Science and Technology最新文献_第10页

Scalable high-dimensional multipartite entanglement with trapped ions 可扩展的高维多部纠缠与捕获离子

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-31 DOI: 10.1088/2058-9565/adac06

Harsh Vardhan Upadhyay, Sanket Tripathy, Ting Rei Tan, Baladitya Suri and Athreya Shankar

{"title":"Scalable high-dimensional multipartite entanglement with trapped ions","authors":"Harsh Vardhan Upadhyay, Sanket Tripathy, Ting Rei Tan, Baladitya Suri and Athreya Shankar","doi":"10.1088/2058-9565/adac06","DOIUrl":"https://doi.org/10.1088/2058-9565/adac06","url":null,"abstract":"We propose a protocol for the preparation of generalized Greenberger–Horne–Zeilinger (GHZ) states of N atoms each with d = 3 or 4 internal levels. We generalize the celebrated one-axis twisting (OAT) Hamiltonian for N qubits to qudits by including OAT interactions of equal strengths between every pair of qudit levels, a protocol we call as balanced OAT (BOAT). Analogous to OAT for qubits, we find that starting from a product state of an arbitrary number of atoms N, dynamics under BOAT leads to the formation of GHZ states for qutrits (d = 3) and ququarts (d = 4). While BOAT could potentially be realized on several platforms where all-to-all coupling is possible, here we propose specific implementations using trapped ion systems. We show that preparing these states with fidelity above a threshold value rules out lower dimensional entanglement than that of the generalized GHZ states. For qutrits, we also propose a protocol to bound the fidelity that requires only global addressing of the ion crystal and single-shot readout of one of the levels. Our results open a path for the scalable generation and certification of high-dimensional multipartite entanglement on current atom-based quantum hardware.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"54 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077520","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 enhanced precision in thermometry with nonlinear qubits 利用非线性量子比特提高测温精度

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-29 DOI: 10.1088/2058-9565/adac05

Sebastian Deffner

引用次数: 0

Quantum data encoding as a distinct abstraction layer in the design of quantum circuits 量子数据编码是量子电路设计中一个独特的抽象层

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-28 DOI: 10.1088/2058-9565/ada6f8

Gabriele Agliardi and Enrico Prati

{"title":"Quantum data encoding as a distinct abstraction layer in the design of quantum circuits","authors":"Gabriele Agliardi and Enrico Prati","doi":"10.1088/2058-9565/ada6f8","DOIUrl":"https://doi.org/10.1088/2058-9565/ada6f8","url":null,"abstract":"Complex quantum circuits are constituted by combinations of quantum subroutines. The computation is possible as long as the quantum data encoding is consistent throughout the circuit. Despite its fundamental importance, the formalization of quantum data encoding has never been addressed systematically so far. We formalize the concept of quantum data encoding, namely the format providing a representation of a data set through a quantum state, as a distinct abstract layer with respect to the associated data loading circuit. We survey existing encoding methods and their respective strategies for classical-to-quantum exact and approximate data loading, for the quantum-to-classical extraction of information from states, and for quantum-to-quantum encoding conversion. Next, we show how major quantum algorithms find a natural interpretation in terms of data loading. For instance, the quantum Fourier transform is described as a quantum encoding converter, while the quantum amplitude estimation as an extraction routine. The new conceptual framework is exemplified by considering its application to the simple case of the Bernstein–Vazirani algorithm, and then to quantum-based Monte Carlo simulations, thus showcasing the power of the proposed formalism for the description of complex quantum circuits. Indeed, the approach clarifies the structure of complex quantum circuits and enables their efficient design.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"20 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077535","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 algorithm for polaritonic chemistry based on an exact ansatz 基于精确ansatz的极化化学量子算法

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-28 DOI: 10.1088/2058-9565/ad9fa5

Samuel Warren, Yuchen Wang, Carlos L Benavides-Riveros and David A Mazziotti

引用次数: 0

Distributing quantum correlations through local operations and classical resources 通过局部操作和经典资源分配量子相关性

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-27 DOI: 10.1088/2058-9565/ada79c

Adam G Hawkins, Hannah McAleese and Mauro Paternostro

引用次数: 0

Atom interferometer as a freely falling clock for time-dilation measurements 原子干涉仪作为时间膨胀测量的自由落体钟

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-22 DOI: 10.1088/2058-9565/ad9e2e

Albert Roura

引用次数: 0

Learning to classify quantum phases of matter with a few measurements 学习通过一些测量对物质的量子相进行分类

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-20 DOI: 10.1088/2058-9565/ada79b

Mehran Khosrojerdi, Jason L Pereira, Alessandro Cuccoli and Leonardo Banchi

引用次数: 0

Conditions for a quadratic quantum speedup in nonlinear transforms with applications to energy contract pricing 非线性变换中二次量子加速的条件及其在能源合约定价中的应用

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-16 DOI: 10.1088/2058-9565/ada08c

Gabriele Agliardi, Corey O’Meara, Kavitha Yogaraj, Kumar Ghosh, Piergiacomo Sabino, Marina Fernández-Campoamor, Giorgio Cortiana, Juan Bernabé-Moreno, Francesco Tacchino, Antonio Mezzacapo and Omar Shehab

{"title":"Conditions for a quadratic quantum speedup in nonlinear transforms with applications to energy contract pricing","authors":"Gabriele Agliardi, Corey O’Meara, Kavitha Yogaraj, Kumar Ghosh, Piergiacomo Sabino, Marina Fernández-Campoamor, Giorgio Cortiana, Juan Bernabé-Moreno, Francesco Tacchino, Antonio Mezzacapo and Omar Shehab","doi":"10.1088/2058-9565/ada08c","DOIUrl":"https://doi.org/10.1088/2058-9565/ada08c","url":null,"abstract":"Computing nonlinear functions over multilinear forms is a general problem with applications in risk analysis. For instance in the domain of energy economics, accurate and timely risk management demands for efficient simulation of millions of scenarios, largely benefiting from computational speedups. We develop a novel hybrid quantum–classical algorithm based on polynomial approximation of nonlinear functions, computed through Quantum Hadamard Products, and we rigorously assess the conditions for its end-to-end speedup for different implementation variants against classical algorithms. In our setting, a quadratic quantum speedup, up to polylogarithmic factors, can be proven only when forms are bilinear and approximating polynomials have second degree, if efficient loading unitaries are available for the input data sets. We also enhance the bidirectional encoding, that allows tuning the balance between circuit depth and width, proposing an improved version that can be exploited for the calculation of inner products. Lastly, we exploit the dynamic circuit capabilities, recently introduced on IBM Quantum devices, to reduce the average depth of the Quantum Hadamard Product circuit. A proof of principle is implemented and validated on IBM Quantum systems.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"93 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986041","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

Automated quantum system modeling with machine learning 使用机器学习的自动量子系统建模

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-16 DOI: 10.1088/2058-9565/ada79a

K Mukherjee, J Schachenmayer, S Whitlock and S Wüster

引用次数: 0

Challenging excited states from adaptive quantum eigensolvers: subspace expansions vs. state-averaged strategies 自适应量子特征解的激发态挑战：子空间展开与状态平均策略

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-01-10 DOI: 10.1088/2058-9565/ad9fa2

Harper R Grimsley and Francesco A Evangelista

{"title":"Challenging excited states from adaptive quantum eigensolvers: subspace expansions vs. state-averaged strategies","authors":"Harper R Grimsley and Francesco A Evangelista","doi":"10.1088/2058-9565/ad9fa2","DOIUrl":"https://doi.org/10.1088/2058-9565/ad9fa2","url":null,"abstract":"The prediction of electronic structure for strongly correlated molecules represents a promising application for near-term quantum computers. Significant attention has been paid to ground state wavefunctions, but excited states of molecules are relatively unexplored. In this work, we consider the adaptive, problem-tailored (ADAPT)-variational quantum eigensolver (VQE) algorithm, a single-reference approach for obtaining ground states, and its state-averaged generalization for computing multiple states at once. We demonstrate for both rectangular and linear H4, as well as for BeH2, that this approach, which we call multistate-objective, Ritz-eigenspectral (MORE)-ADAPT-VQE, can make better use of small excitation manifolds than an analogous method based on a single-reference ADAPT-VQE calculation, q-sc-EOM. In particular, MORE-ADAPT-VQE is able to accurately describe both avoided crossings and crossings between states of different symmetries. In addition to more accurate excited state energies, MORE-ADAPT-VQE can recover accurate transition dipole moments in situations where traditional ADAPT-VQE and q-sc-EOM struggle. These improvements suggest a promising direction toward the use of quantum computers for difficult excited state problems.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"9 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939758","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