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Energy filter methods in combination with quantum simulation can efficiently access the properties of quantum many-body systems at finite energy densities [Lu et al. PRX Quantum 2, 020321 (2021)]. Classically simulating this algorithm with…

Quantum Physics · Physics 2024-07-08 Maxine Luo , Rahul Trivedi , Mari Carmen Bañuls , J. Ignacio Cirac

We construct quantum algorithms to compute physical observables of nonlinear PDEs with M initial data. Based on an exact mapping between nonlinear and linear PDEs using the level set method, these new quantum algorithms for nonlinear…

Quantum Physics · Physics 2025-04-22 Shi Jin , Nana Liu

The diagonalization of matrices may be the top priority in the application of modern physics. In this paper, we numerically demonstrate that, for real symmetric random matrices with non-positive off-diagonal elements, a universal scaling…

Quantum Physics · Physics 2020-11-06 Wei Pan , Jing Wang , Deyan Sun

Noisy intermediate-scale quantum (NISQ) devices offer unique platforms to test and evaluate the behavior of non-fault-tolerant quantum computing. However, validating programs on NISQ devices is difficult due to fluctuations in the…

Quantum Physics · Physics 2022-01-10 Megan L. Dahlhauser , Travis S. Humble

Finding ground states and low-lying excitations of a given Hamiltonian is one of the most important problems in many fields of physics. As a novel approach, quantum computing on Noisy Intermediate-Scale Quantum (NISQ) devices offers the…

The Poisson equation has wide applications in many areas of science and engineering. Although there are some quantum algorithms that can efficiently solve the Poisson equation, they generally require a fault-tolerant quantum computer which…

Quantum Physics · Physics 2021-08-25 Hailing Liu , Yusen Wu , Linchun Wan , Shijie Pan , Sujuan Qin , Fei Gao , Qiaoyan Wen

There is widespread interest in calculating the energy spectrum of a Hamiltonian, for example to analyze optical spectra and energy deposition by ions in materials. In this study, we propose a quantum algorithm that samples the set of…

We propose a class of randomized quantum algorithms for the task of sampling from matrix functions, without the use of quantum block encodings or any other coherent oracle access to the matrix elements. As such, our use of qubits is purely…

Quantum Physics · Physics 2024-05-22 Samson Wang , Sam McArdle , Mario Berta

Solving non-Hermitian quantum many-body systems on a quantum computer by minimizing the variational energy is challenging as the energy can be complex. Here, based on energy variance, we propose a variational method for solving the…

Quantum Physics · Physics 2024-02-21 Xu-Dan Xie , Zheng-Yuan Xue , Dan-Bo Zhang

Quantum search algorithm (also known as Grover's algorithm) lays the foundation for many other quantum algorithms. Although it is very simple, its implementation is limited on noisy intermediate-scale quantum (NISQ) processors. Grover's…

Quantum Physics · Physics 2022-09-28 Kun Zhang , Kwangmin Yu , Vladimir Korepin

An observer-based Hamiltonian identification algorithm for quantum systems is proposed. For the 2-level case an exponential convergence result based on averaging arguments and some relevant transformations is provided. The convergence for…

Mathematical Physics · Physics 2007-05-23 Mazyar Mirrahimi , Pierre Rouchon

We review two algorithmic advances that bring us closer to reliable quantum simulations of model systems in high energy physics and beyond on noisy intermediate-scale quantum (NISQ) devices. The first method is the dimensional expressivity…

Hybrid quantum-classical algorithms are among the most promising systems to implement quantum computing under the Noisy-Intermediate Scale Quantum (NISQ) technology. In this paper, at first, we investigate a quantum dynamics algorithm for…

Quantum Physics · Physics 2020-08-13 Mahmoud Mahdian , H. Davoodi Yeganeh

Besides the traditional circuit-based model of quantum computation, several quantum algorithms based on a continuous-time Hamiltonian evolution have recently been introduced, including for instance continuous-time quantum walk algorithms as…

Quantum Physics · Physics 2007-05-23 Jeremie Roland , Nicolas J. Cerf

The Variational Quantum Eigensolver (VQE) algorithm, as applied to finding the ground state of a Hamiltonian, is particularly well-suited for deployment on noisy intermediate-scale quantum (NISQ) devices. Here we utilize the VQE algorithm…

Quantum Physics · Physics 2024-11-28 Younes Javanmard , Ugne Liaubaite , Tobias J. Osborne , Xusheng Xu , Man-Hong Yung

We present a quantum algorithm for estimating the matrix determinant based on quantum spectral sampling. The algorithm estimates the logarithm of the determinant of an $n \times n$ positive sparse matrix to an accuracy $\epsilon$ in time…

Quantum Physics · Physics 2025-05-02 Vittorio Giovannetti , Seth Lloyd , Lorenzo Maccone

We propose a quantum algorithm for finding eigenvalues of non-unitary matrices. We show how to construct, through interactions in a quantum system and projective measurements, a non-Hermitian or non-unitary matrix and obtain its eigenvalues…

Quantum Physics · Physics 2010-12-07 Hefeng Wang , Lian-Ao Wu , Yu-xi Liu , Franco Nori

A new method for generating analytical expression of quantum Hamiltonian from non-linear differential equation with stationary energy level has been formulated.Further calculation of energy levels have been carried out analytically using…

Quantum Physics · Physics 2014-12-30 Biswanath Rath , P. Mallick

We propose quantum algorithms, purely quantum in nature, for calculating the determinant and inverse of an $(N-1)\times (N-1)$ matrix (depth is $O(N^2\log N)$) which is a simple modification of the algorithm for calculating the determinant…

Quantum Physics · Physics 2025-06-02 Alexander I. Zenchuk , Georgii A. Bochkin , Wentao Qi , Asutosh Kumar , Junde Wu

State-of-the-art noisy intermediate-scale quantum devices (NISQ), although imperfect, enable computational tasks that are manifestly beyond the capabilities of modern classical supercomputers. However, present quantum computations are…