检索结果-内蒙古大学图书馆

4th IEEE International Conference on quantum Computing and Engineering, QCE 2023

作者： Galvis-Florez, Cristian A. Reitzner, Daniel Särkkä, Simo Aalto University Department of Electrical Engineering and Automation Espoo Finland Quantum Algorithms and Software Vtt Technical Research Centre of Finland Espoo Finland

ISBN: (纸本)9798350343236

Current quantum computers have the potential to overcome classical computational methods, however, the capability of the algorithms that can be executed on noisy intermediate-scale quantum devices is limited due to hardware imperfections. Estimating the state of a qubit is often needed in different quantum protocols, due to the lack of direct measurements. In this paper, we consider the problem of estimating the quantum state of a qubit in a quantum processing unit without conducting direct measurements of it. We consider a parameterized measurement model to estimate the quantum state, represented as a quantum circuit, which is optimized using the quantum tomographic transfer function. We implement and test the circuit using the quantum computer of the Technical Research Centre of Finland as well as an IBM quantum computer. We demonstrate that the set of positive operator-valued measurements used for the estimation is symmetric and informationally complete. Moreover, the resources needed for qubit estimation are reduced when direct measurements are allowed, keeping the symmetric property of the measurements. © 2023 IEEE.

关键词： Qubits

来源：评论

学校读者我要写书评

暂无评论

Introduction to the Special Issue on quantum Computing and Operations Research

引用

INFORMS JOURNAL ON COMPUTING 2025年第1期37卷 1-196, C2页

作者： Coffrin, Carleton Lobe, Elisabeth Nannicini, Giacomo Parekh, Ojas Los Alamos Natl Lab Adv Network Sci Initiat Los Alamos NM 87545 USA German Aerosp Ctr DLR Inst Software Technol D-38108 Braunschweig Germany Univ Southern Calif Dept Ind & Syst Engn Los Angeles CA 90089 USA Sandia Natl Labs Quantum Algorithms & Applicat Collaboratory QuAAC Albuquerque NM 87123 USA

来源：评论

学校读者我要写书评

暂无评论

Interacting Electrons in a Flat-Band System within the Generalized Kadanoff-Baym Ansatz

引用

PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS 2024年第9期261卷

作者： Cosco, Francesco Tuovinen, Riku Lo Gullo, Nicolino VTT Tech Res Ctr Finland Ltd Quantum Algorithms & Software Tietotie 3 Espoo 02150 Finland Univ Jyvaskyla Dept Phys Nanosci Ctr Box 35 Jyvaskyla 40014 Finland Univ Calabria Dipartimento Fis I-87036 Arcavacata Di Rende CS Italy INFN Sez LNF Grp Collegato Cosenza I-87036 Arcavacata Di Rende CS Italy

In this work, the study of the spectral properties of an open interacting system by solving the generalized Kadanoff-Baym ansatz (GKBA) master equation for the single-particle density matrix, namely the time-diagonal lesser Green's function, is reported. To benchmark its validity, the solution obtained within the GKBA is compared with the solution of the Dyson equation at stationarity. In both approaches, the interaction is treated within the self-consistent second-order Born approximation, whereas the GKBA still retains the retarded propagator calculated at the Hartree-Fock (HF) and wideband limit approximation level. The model chosen is that of two leads connected through a central correlated region where particles can interact and utilize the stationary particle current at the boundary of the junction as a probe of the spectral features of the system. The central region is chosen as the simplest model featuring a degenerate ground state with a flat band. The main result is that the solution of the GKBA master equation captures well the spectral feature of such system and specifically the transition from dispersionless to dispersive behavior of the flat band as the interaction is increased. Therefore, the GBKA solution retains the main spectral features of the self-energy used even when the propagator is at the HF level. Herein, the nonequilibrium Green's function approach is employed to study transport across a correlated 1D system featuring a flat band in its single-particle energy spectrum. Specifically, the results of the solution of the stationary Dyson equation are compared with those obtained by the generalized Kadanoff-Baym ansatz (GKBA) master equation. Good agreement is found between the two although the GBKA approach used here does not account for correlations in the retarded propagator. Strikingly, the restoration of transport is observed through the otherwise nonconductive flat *** (c) 2024 WILEY-VCH GmbH

关键词： flat bands generalized Kadanoff-Baym ansatz quantum transports

来源：评论

学校读者我要写书评

暂无评论

Exploring the trade-off between computational power and energy efficiency: An analysis of the evolution of quantum computing and its relation to classical computing

引用

JOURNAL OF SYSTEMS AND software 2024年 217卷

作者： Desdentado, Elena Calero, Coral Moraga, Ma Angeles Serrano, Manuel Garcia, Felix Univ Castilla La Mancha Inst Technol & Informat Syst Camino Moledores S-N Ciudad Real 13005 Spain aQuantum Green Quantum Algorithms & Software Res Madrid Spain

quantum computing is considered a revolutionary technology due to its ability to solve computational problems that are beyond the capabilities of classical computers. However, quantum computing requires great amounts of energy to run. Therefore, a factor in deciding whether to use quantum computing should be not only the complexity of the problem to be solved, but also the energy required to solve it. This paper presents an empirical study developed with the aim of comparing classical and quantum computing in terms of energy efficiency to determine whether the increased power of quantum computers is offset by their higher energy consumption. To achieve this, a variety of problems with different levels of complexity were tested on both types of computers. Specifically, we used the IBM quantum computers with a maximum of 5 qubits and an Intel i7, as a classical computer. In addition to this we have also analysed the evolution of the quantum computers, performing measurements on three time periods. Our empirical study showed that there is a variability of results obtained in the three time periods and that quantum computing is not recommended for low-complexity problems, given its high energy consumption, particularly when compared to traditional computing.

关键词： software quantum computing Green software Green quantum Energy consumption Energy efficiency

来源：评论

学校读者我要写书评

暂无评论

Single Qubit State Estimation on NISQ Devices with Limited Resources and SIC-POVMs

Single Qubit State Estimation on NISQ Devices with Limited R...

引用

quantum Computing and Engineering (QCE), IEEE International Conference on

作者： Cristian A. Galvis-Florez Daniel Reitzner Simo Särkkä Department of Electrical Engineering and Automation Aalto University Espoo Finland Quantum Algorithms and Software VTT Technical Research Centre of Finland Espoo Finland

关键词：

来源：评论

学校读者我要写书评

暂无评论

Single Qubit State Estimation on NISQ Devices with Limited Resources and SIC-POVMs

arXiv

引用

arXiv 2023年

作者： Galvis-Florez, Cristian A. Reitzner, Daniel Särkkä, Simo Department of Electrical Engineering and Automation Aalto University Espoo Finland Quantum Algorithms and Software VTT Technical Research Centre of Finland Espoo Finland

关键词： Qubits

来源：评论

学校读者我要写书评

暂无评论

General measurements with limited resources and their application to quantum unambiguous state discrimination

引用

quantum INFORMATION PROCESSING 2024年第7期23卷 268-268页

作者： Reitzner, Daniel Bouda, Jan VTT Tech Res Ctr Finland Quantum Algorithms & Software POB 1000 Espoo 02044 Finland Masaryk Univ Fac Informat Botanicka 68a Brno 60200 Czech Republic Slovak Acad Sci Inst Phys RCQI Dubravska cesta 9 Bratislava 84511 Slovakia

In this report, we present a framework for implementing an arbitrary n-outcome generalized quantum measurement (POVM) on an m-qubit register as a sequence of two-outcome measurements requiring only single ancillary qubit. Our procedure offers a particular construction for the two-outcome partial measurements which can be composed into a full implementation of the measurement on any gate architecture. This implementation in general requires classical feedback;we present specific cases when this is not the case. We apply this framework on the unambiguous state discrimination and analyze possible strategies. In the simplest case, it gives the same construction as is known, if we opt for performing conclusiveness measurement first. However, it also offers possibility of performing measurement for one of the state outcomes first, leaving conclusiveness measurement for later. This shows flexibility of presented framework and opens possibilities for further optimization. We present discussion also on biased qubit case as well as general case of unambiguous quantum state discrimination in higher dimension.

关键词： Generalized quantum measurements POVM implementation Sequential measurements Unambiguous state discrimination

来源：评论

学校读者我要写书评

暂无评论

Enhancing qubit readout with Bayesian learning

引用

Physical Review A 2023年第6期108卷 L060402-L060402页

作者： F. Cosco N. Lo Gullo Quantum Algorithms and Software VTT Technical Research Centre of Finland Ltd Tietotie 3 02150 Espoo Finland Dipartimento di Fisica Università della Calabria Arcavacata di Rende I-87036 Cosenza Italy INFN - Gruppo Collegato di Cosenza Arcavacata di Rende I-87036 Cosenza Italy

We introduce an efficient and accurate readout measurement scheme for single and multiqubit states. Our method uses Bayesian inference to build an assignment probability distribution for each qubit state based on a reference characterization of the detector response functions. This allows us to account for system imperfections and thermal noise within the assignment of the computational basis. We benchmark our protocol on a quantum device with five superconducting qubits, testing initial state preparation for single- and two-qubit states and an application of the Bernstein-Vazirani algorithm executed on five qubits. Our method shows a substantial reduction of the readout error and promises advantages for near-term and future quantum devices.

关键词： quantum algorithms & computation quantum computation quantum parameter estimation

来源：评论

学校读者我要写书评

暂无评论

Perturbative approaches to quantum field theory in curved space-time

arXiv

引用

arXiv 2022年

作者： Huhtala, Jesse Vilja, Iiro Gullo, Nicola Lo Department of Physics and Astronomy University of Turku Turku20014 Finland Quantum algorithms and software VTT Technical Research Centre of Finland Ltd Finland 87036 Italy

Despite the large amount of work done in quantum field theory in curved space-times, there are not great many results available for perturbative calculations of particle processes in these systems. Such processes are expected to be important in the early stages of the universe, as well as near highly relativistic objects like black holes and, recently, in effective field theories of condensed matter systems. The difficulties with carrying out perturbative calculations in curved space-times are related to the practical difficulty of quantizing in curved space-times. This suggests the need for investigating new approximations and comparing the results of different methods of carrying out the calculations. In this paper, we compare different perturbative approaches to particle scattering problems and illustrate them with examples. In particular, we look at a 1+1 dimensional static spacetime. We also examine the spacetime particle generation in a 1+1 Robertson-Walker universe, where we find that the curved space LSZ formula yields new information compared to the in-in formalism. Copyright © 2022, The Authors. All rights reserved.

关键词： Black holes

来源：评论

学校读者我要写书评

暂无评论

Dispensing of quantum information beyond no-broadcasting theorem-is it possible to broadcast anything genuinely quantum?

引用

JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL 2023年第13期56卷 135301-135301页

作者： Heinosaari, Teiko Jencova, Anna Plavala, Martin VTT Tech Res Ctr Finland Ltd Quantum Algorithms & Software Tampere Finland Univ Turku Dept Phys & Astron Turku 20014 Finland Slovak Acad Sci Math Inst Bratislava Slovakia Univ Siegen Naturwissenschaftlich Tech Fak D-57068 Siegen Germany

No-broadcasting theorem is one of the most fundamental results in quantum information theory;it guarantees that the simplest attacks on any quantum protocol, based on eavesdropping and copying of quantum information, are impossible. Due to the fundamental importance of the no-broadcasting theorem, it is essential to understand the exact boundaries of this limitation. We generalize the standard definition of broadcasting by restricting the set of states which we want to broadcast and restricting the sets of measurements which we use to test the broadcasting. We show that in some of the investigated cases broadcasting is equivalent to commutativity, while in other cases commutativity is not necessary.

关键词： no-broadcasting no-cloning commutativity

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：