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Related papers: Quantum Algorithm For Estimating Eigenvalue

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The generalized eigenvalue (GE) problems are of particular importance in various areas of science engineering and machine learning. We present a variational quantum algorithm for finding the desired generalized eigenvalue of the GE problem,…

Quantum Physics · Physics 2022-03-08 Jin-Min Liang , Shu-Qian Shen , Ming Li , Shao-Ming Fei

We introduce two kinds of quantum algorithms to explore microcanonical and canonical properties of many-body systems. The first one is a hybrid quantum algorithm that, given an efficiently preparable state, computes expectation values in a…

Quantum Physics · Physics 2021-05-19 Sirui Lu , Mari Carmen Bañuls , J. Ignacio Cirac

The efficient simulation of quantum dynamics and ground states is a central challenge in physics and a key frontier for quantum advantage. While short-time evolution in one-dimensional systems can often be simulated classically, extending…

Quantum Physics · Physics 2025-09-22 Yusen Wu , Yukun Zhang , Chuan Wang , Xiao Yuan

This thesis explores hybrid algorithms that combine classical and quantum computing to enhance the performance of classical algorithms. Two approaches are studied: a hybrid search and sample optimization algorithm and a classical algorithm…

Quantum Physics · Physics 2024-06-19 Roberto Campos

We report an attempt to calculate energy eigenvalues of large quantum systems by the diagonalization of an effectively truncated Hamiltonian matrix. For this purpose we employ a specific way to systematically make a set of orthogonal states…

Strongly Correlated Electrons · Physics 2009-10-31 T. Munehisa , Y. Munehisa

We describe a quantum algorithm for preparing states that encode solutions of non-homogeneous linear partial differential equations. The algorithm is a continuous-variable version of matrix inversion: it efficiently inverts differential…

Quantum Physics · Physics 2019-09-11 Juan Miguel Arrazola , Timjan Kalajdzievski , Christian Weedbrook , Seth Lloyd

We introduce a classical-quantum hybrid approach to computation, allowing for a quadratic performance improvement in the decision process of a learning agent. In particular, a quantum routine is described, which encodes on a quantum…

Quantum Physics · Physics 2023-03-22 A. Sannia , A. Giordano , N. Lo Gullo , C. Mastroianni , F. Plastina

Estimating the eigenvalue or energy gap of a Hamiltonian H is vital for studying quantum many-body systems. Particularly, many of the problems in quantum chemistry, condensed matter physics, and nuclear physics investigate the energy gap…

Quantum Physics · Physics 2023-05-22 Yongdan Yang , Ying Li , Xiaosi Xu , Xiao Yuan

The efficient implementation of matrix arithmetic operations underpins the speedups of many quantum algorithms. We develop a suite of methods to perform matrix arithmetics -- with the result encoded in the off-diagonal blocks of a…

Quantum Physics · Physics 2026-01-23 Christopher Kang , Yuan Su

The use of near-term quantum devices that lack quantum error correction, for addressing quantum chemistry and physics problems, requires hybrid quantum-classical algorithms and techniques. Here we present a process for obtaining the…

Quantum Physics · Physics 2023-08-14 Pejman Jouzdani , Stefan Bringuier

A powerful method for calculating the eigenvalues of a Hamiltonian operator consists of converting the energy eigenvalue equation into a matrix equation by means of an appropriate basis set of functions. The convergence of the method can be…

Quantum Physics · Physics 2007-05-23 Paolo Amore , Alfredo Aranda , Francisco Fernandez , Hugh Jones

We propose an iterative improvement method for the Harrow-Hassidim-Lloyd (HHL) algorithm to solve a linear system of equations. This is a quantum-classical hybrid algorithm. The accuracy is essential to solve the linear system of equations.…

Quantum Physics · Physics 2021-08-18 Yoshiyuki Saito , Xinwei Lee , Dongsheng Cai , Nobuyoshi Asai

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…

The simulation of large-scale classical systems in exponentially small space on quantum computers has gained attention. The prior work demonstrated that a quantum algorithm offers an exponential speedup over any classical algorithm in…

Quantum Physics · Physics 2026-03-02 Kazuki Sakamoto , Keisuke Fujii

We present quantum algorithms to efficiently perform discriminant analysis for dimensionality reduction and classification over an exponentially large input data set. Compared with the best-known classical algorithms, the quantum algorithms…

Quantum Physics · Physics 2016-07-12 Iris Cong , Luming Duan

In this paper, we explore accelerating Hamiltonian ground state energy calculation on NISQ devices. We suggest using search-based methods together with machine learning to accelerate quantum algorithms, exemplified in the Quantum…

Quantum Physics · Physics 2026-05-11 Avner Bensoussan , Elena Chachkarova , Karine Even-Mendoza , Sophie Fortz , Connor Lenihan

Though quantum algorithm acts as an important role in quantum computation science, not only for providing a great vision for solving classically unsolvable problems, but also due to the fact that it gives a potential way of understanding…

Quantum Physics · Physics 2015-08-11 Xiang Zhan , Jian Li , Hao Qin , Zhihao Bian , Peng Xue

We present an algorithm for measurement of $k$-local operators in a quantum state, which scales logarithmically both in the system size and the output accuracy. The key ingredients of the algorithm are a digital representation of the…

Quantum Physics · Physics 2018-10-16 Apoorva Patel , Anjani Priyadarsini

At large scales, quantum systems may become advantageous over their classical counterparts at performing certain tasks. Developing tools to analyse these systems at the relevant scales, in a manner consistent with quantum mechanics, is…

Quantum Physics · Physics 2024-11-12 Timon Schapeler , Robert Schade , Michael Lass , Christian Plessl , Tim J. Bartley

We present an approach, which we term quantum-enhanced optimization, to accelerate classical optimization algorithms by leveraging quantum sampling. Our method uses quantum-generated samples as warm starts to classical heuristics for…

Quantum Physics · Physics 2025-08-25 Ieva Čepaitė , Niam Vaishnav , Leo Zhou , Ashley Montanaro