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Related papers: Quantum Algorithm For Estimating Eigenvalue

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We present an efficient method for preparing the initial state required by the eigenvalue approximation quantum algorithm of Abrams and Lloyd. Our method can be applied when solving continuous Hermitian eigenproblems, e.g., the Schroedinger…

Quantum Physics · Physics 2009-11-10 Peter Jaksch , Anargyros Papageorgiou

Quantum computers are predicted to outperform classical ones for solving partial differential equations, perhaps exponentially. Here we consider a prototypical PDE - the heat equation in a rectangular region - and compare in detail the…

Quantum Physics · Physics 2020-06-19 Noah Linden , Ashley Montanaro , Changpeng Shao

We present a new algorithm that computes eigenvalues and eigenvectors of a Hermitian positive definite matrix while solving a linear system of equations with Conjugate Gradient (CG). Traditionally, all the CG iteration vectors could be…

High Energy Physics - Lattice · Physics 2011-10-12 Andreas Stathopoulos , Kostas Orginos

Quantum computers may achieve speedups over their classical counterparts for solving linear algebra problems. However, in some cases -- such as for low-rank matrices -- dequantized algorithms demonstrate that there cannot be an exponential…

Quantum Physics · Physics 2023-05-16 Ashley Montanaro , Changpeng Shao

Quantum computers can be used to address molecular structure, materials science and condensed matter physics problems, which currently stretch the limits of existing high-performance computing resources. Finding exact numerical solutions to…

In this paper, we explore using the Harrow-Hassidim-Lloyd (HHL) algorithm to address scientific and engineering problems through quantum computing, utilizing the NWQSim simulation package on a high-performance computing platform. Focusing…

Quantum Physics · Physics 2025-08-08 Muqing Zheng , Chenxu Liu , Samuel Stein , Xiangyu Li , Johannes Mülmenstädt , Yousu Chen , Ang Li

Solving eigenproblem of the Laplacian matrix of a fully connected weighted graph has wide applications in data science, machine learning, and image processing, etc. However, this is very challenging because it involves expensive matrix…

Quantum Physics · Physics 2022-05-31 Hai-Ling Liu , Su-Juan Qin , Lin-Chun Wan , Chao-Hua Yu , Shi-Jie Pan , Fei Gao , Qiao-Yan Wen

This work presents a novel approach to compute the eigenvalues of non-Hermitian matrices using an enhanced shifted QR algorithm. The existing QR algorithms fail to converge early in the case of non-hermitian matrices, and our approach shows…

Numerical Analysis · Mathematics 2025-10-16 Chahat Ahuja , Partha Chowdhury , Subhashree Mohapatra

We derive out a complete series expression of Hamiltonian eigenvalues without any approximation and cut in the general quantum systems based on Wang's formal framework \cite{wang1}. In particular, we then propose a calculating approach of…

Quantum Physics · Physics 2009-11-12 Zhou Li , An Min Wang

Achieving a provable exponential quantum speedup for an important machine learning task has been a central research goal since the seminal HHL quantum algorithm for solving linear systems and the subsequent quantum recommender systems…

Quantum Physics · Physics 2025-12-03 Allan Grønlund , Kasper Green Larsen

A hybrid quantum-classical algorithm is a computational scheme in which quantum circuits are used to extract information that is then processed by a classical routine to guide subsequent quantum operations. These algorithms are especially…

Quantum Physics · Physics 2025-09-03 Alon Levi , Ziv Ossi , Eliahu Cohen , Amit Te'eni

Harnessing the full power of nascent quantum processors requires the efficient management of a limited number of quantum bits with finite lifetime. Hybrid algorithms leveraging classical resources have demonstrated promising initial results…

Solving linear systems of equations is ubiquitous in all areas of science and engineering. With rapidly growing data sets, such a task can be intractable for classical computers, as the best known classical algorithms require a time…

We apply numerical optimization and linear algebra algorithms for classical computers to the problem of automatically synthesizing algorithms for quantum computers. Using our framework, we apply several common techniques from these…

Numerical Analysis · Mathematics 2025-09-16 Yuxin Huang , Benjamin E. Grossman-Ponemon , David A. B. Hyde

An algorithm to classify a general Hermitian matrix according to its signature (positive semi-definite, negative or indefinite) is presented. It builds on the Quantum Phase Estimation algorithm, which stores the sign of the eigenvalues of a…

Quantum Physics · Physics 2022-11-28 Andrés Gómez , Javier Mas

Linear differential equations are ubiquitous in science and engineering. Quantum computers can simulate quantum systems, which are described by a restricted type of linear differential equations. Here we extend quantum simulation algorithms…

Quantum Physics · Physics 2014-02-21 Dominic W. Berry

A theoretical analysis is given of the equation of motion method, due to Alben et al., to compute the eigenvalue distribution (density of states) of very large matrices. The salient feature of this method is that for matrices of the kind…

Computational Physics · Physics 2009-11-06 Anthony Hams , Hans De Raedt

While it seems possible that quantum computers may allow for algorithms offering a computational speed-up over classical algorithms for some problems, the issue is poorly understood. We explore this computational speed-up by investigating…

Quantum Physics · Physics 2010-06-09 Alastair A. Abbott , Cristian S. Calude

Quantum computing promises the ability to compute properties of quantum systems exponentially faster than classical computers. Quantum advantage is achieved when a practical problem is solved more efficiently on a quantum computer than on a…

Quantum Physics · Physics 2025-12-03 William A. Simon , Peter J. Love

Power flow calculation plays an important role in planning, operation, and control of the power system. The quantum HHL algorithm can achieve theoretical exponential speedup over classical algorithms on DC power flow calculation. Since the…

Quantum Physics · Physics 2022-06-09 Fang Gao , Guojian Wu , Suhang Guo , Wei Dai , Feng Shuang