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Significant effort in applied quantum computing has been devoted to the problem of ground state energy estimation for molecules and materials. Yet, for many applications of practical value, additional properties of the ground state must be…

Quantum Physics · Physics 2022-07-13 Ruizhe Zhang , Guoming Wang , Peter Johnson

Uncertainty quantification (UQ) tasks, such as sensitivity analysis and parameter estimation, entail a huge computational complexity when dealing with input-output maps involving the solution of nonlinear differential problems, because of…

Numerical Analysis · Mathematics 2023-02-17 Ludovica Cicci , Stefania Fresca , Mengwu Guo , Andrea Manzoni , Paolo Zunino

The determination of ultra-long-range molecular potential curves has been reformulated using the Coulomb Greens function to give a solution in terms of the roots of an analytical determinantal equation. For a system consisting of one…

Atomic Physics · Physics 2025-11-25 Chris H. Greene , Matthew T. Eiles

An end-to-end strategy for hybrid quantum-classical computations of Green's functions in many-body systems is presented and applied to the pairing model. The scheme makes explicit use of the spectral representation of the Green's function,…

Nuclear Theory · Physics 2026-05-01 Samuel Aychet-Claisse , Denis Lacroix , Vittorio Somà , Jing Zhang

We propose and apply the finite-element discrete variable representation to express the nonequilibrium Green's function for strongly inhomogeneous quantum systems. This method is highly favorable against a general basis approach with regard…

Strongly Correlated Electrons · Physics 2013-05-29 K. Balzer , S. Bauch , M. Bonitz

Reduced Order Quadrature (ROQ) methods can greatly reduce the computational cost of Gravitational Wave (GW) likelihood evaluations, and therefore greatly speed up parameter estimation analyses, which is a vital part to maximize the science…

General Relativity and Quantum Cosmology · Physics 2023-12-18 Gonzalo Morras , Jose Francisco Nuno Siles , Juan Garcia-Bellido

We show that cluster algorithms for quantum models have a meaning independent of the basis chosen to construct them. Using this idea, we propose a new method for measuring with little effort a whole class of Green's functions, once a…

Statistical Mechanics · Physics 2015-06-25 R. Brower , S. Chandrasekharan , U. -J. Wiese

In recent years, a great deal of attention has been focused on numerically solving exponential integrators. The important ingredient to the implementation of exponential integrators is the efficient and accurate evaluation of the so called…

Numerical Analysis · Mathematics 2014-09-02 Gang Wu , Lu Zhang , Ting-ting Xu

The Green's function method has applications in several fields in Physics, from classical differential equations to quantum many-body problems. In the quantum context, Green's functions are correlation functions, from which it is possible…

Mesoscale and Nanoscale Physics · Physics 2016-10-14 Mariana M. Odashima , Beatriz G. Prado , E. Vernek

We report a linear-scaling random Green's function (rGF) method for large-scale electronic structure calculation. In this method, the rGF is defined on a set of random states to stochastically express the density matrix, and rGF is…

Mesoscale and Nanoscale Physics · Physics 2024-03-05 Mingfa Tang , Chang Liu , Aixia Zhang , Qingyun Zhang , Shengjun Yuan , Youqi Ke

Designing quantum circuits for ground state preparation is a fundamental task in quantum information science. However, standard Variational Quantum Algorithms (VQAs) are often constrained by limited ansatz expressivity and difficult…

Quantum Physics · Physics 2026-02-25 Zhijian Lai , Hantao Nie , Jiayuan Wu , Dong An

Arnoldi method and conjugate gradient method are important classical iteration methods in solving linear systems and estimating eigenvalues. Their efficiency often affected by the high dimension of the space, where quantum computer can play…

Quantum Physics · Physics 2018-08-15 Changpeng Shao

We show that Green function methods can be straightforwardly applied to nonlinear equations appearing as the leading order of a short time expansion. Higher order corrections can be then computed giving a satisfactory agreement with…

High Energy Physics - Theory · Physics 2008-11-26 Marco Frasca

A quantum algorithm is developed to calculate decay rates and cross sections using quantum resources that scale polynomially in the system size assuming similar scaling for state preparation and time evolution. This is done by computing…

High Energy Physics - Theory · Physics 2020-11-18 Anthony Ciavarella

In this work we have presented a rather general and easy-to-apply method for discrete Hilbert space representation of quantum mechanical Green's operators. We have shown that if in some discrete Hilbert space basis representation the…

Quantum Physics · Physics 2016-09-08 Balázs Kónya

Here we review the many aspects and distinct phenomena associated to quantum dynamics on general graph structures. For so, we discuss such class of systems under the energy domain Green's function ($G$) framework. This approach is…

Quantum Physics · Physics 2016-08-22 Fabiano M. Andrade , A. G. M. Schmidt , E. Vicentini , B. K. Cheng , M. G. E. da Luz

We derive a method to efficiently compute the Green function of on arbitrary Hamiltonians defined on semi-infinite and periodic quasi-one-dimensional lattices. Computing the Green function is the backbone of quantum transport, electronic…

Mesoscale and Nanoscale Physics · Physics 2021-05-18 Pablo San-Jose

In the framework of the hybrid quantum-classical variational cluster approach (VCA) to strongly correlated electron systems one of the goals of a quantum subroutine is to find single-particle correlation functions of lattice fermions in…

Quantum Physics · Physics 2025-06-26 Gino Bishop , Dmitry Bagrets , Frank K. Wilhelm

A new approach proposed recently by author for the calculation of Green functions in quantum field theory and quantum mechanics is briefly reviewed. The method is applied to nonperturbative calculations for anharmonic oscillator,…

High Energy Physics - Theory · Physics 2007-05-23 V. E. Rochev

The accurate and efficient energy estimation of quantum Hamiltonians consisting of Pauli observables is an essential task in modern quantum computing. We introduce a Resource-Optimized Grouping Shadow (ROGS) algorithm, which optimally…

Quantum Physics · Physics 2025-04-09 Min Li , Mao Lin , Matthew J. S. Beach