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The phaseless Auxiliary Field Quantum Monte Carlo method provides a well established approximation scheme for accurate calculations of ground state energies of many-fermions systems. Here we apply the method to the calculation of imaginary…

Strongly Correlated Electrons · Physics 2015-06-17 M. Motta , D. E. Galli , S. Moroni , E. Vitali

We present an elementary and self-contained account of the analogies existing between classical diffusion and the imaginary-time evolution of quantum systems. These analogies are used to develop a new quantum simulation method which allows…

Condensed Matter · Physics 2007-05-23 S. Baroni , S. Moroni

An ab-initio method for determining the dynamical structure function of an interacting many--body quantum system has been devised by combining a generalized integral transform method with Quantum Monte Carlo methods. As a first application,…

Other Condensed Matter · Physics 2012-09-26 Alessandro Roggero , Francesco Pederiva , Giuseppina Orlandini

A new diagrammatic quantum Monte Carlo approach is proposed to deal with the imaginary time propagator involving both dynamic disorder (i.e., electron-phonon interactions) and static disorder of local or nonlocal nature in a unified and…

Materials Science · Physics 2026-04-15 Yu-Chen Wang , Yi Zhao

Monte Carlo studies involving real time dynamics are severely restricted by the sign problem that emerges from highly oscillatory phase of the path integral. In this letter, we present a new method to compute real time quantities on the…

High Energy Physics - Lattice · Physics 2016-08-24 Andrei Alexandru , Gokce Basar , Paulo F. Bedaque , Sohan Vartak , Neill C. Warrington

When a system undergoes a quantum phase transition, the ground-state wave-function shows a change of nature, which can be monitored using the fidelity concept. We introduce two Quantum Monte Carlo schemes that allow the computation of…

Strongly Correlated Electrons · Physics 2009-10-21 David Schwandt , Fabien Alet , Sylvain Capponi

A real-time path integral Monte Carlo approach is developed to study the dynamics in a many-body quantum system until reaching a nonequilibrium stationary state. The approach is based on augmenting an exact reduced equation for the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Lothar Mühlbacher , Eran Rabani

In this paper, we solve quantum many-body problem by propagating ensembles of trajectories and guiding waves in physical space. We introduce the 'effective potential' correction within the recently proposed time-dependent quantum Monte…

Quantum Physics · Physics 2025-02-05 Ivan P. Christov

We introduce a quantum Monte Carlo method to simulate the reversible dynamics of correlated many-body systems. Our method is based on the Laplace transform of the time-evolution operator which, as opposed to most quantum Monte Carlo…

Quantum Physics · Physics 2022-09-14 Romain Chessex , Massimo Borrelli , Hans Christian Öttinger

We show how the worldline quantum Monte Carlo procedure, which usually relies on an artificial time discretization, can be formulated directly in continuous time, rendering the scheme exact. For an arbitrary system with discrete Hilbert…

Condensed Matter · Physics 2009-10-30 N. V. Prokof'ev , B. V. Svistunov , I. S. Tupitsyn

An efficient Path Integral Monte Carlo procedure is proposed to simulate the behavior of quantum many-body dissipative systems described within the framework of the influence functional. Thermodynamic observables are obtained by Monte Carlo…

Statistical Mechanics · Physics 2009-11-07 Luca Capriotti , Alessandro Cuccoli , Andrea Fubini , Valerio Tognetti , Ruggero Vaia

We have simulated the ground states of quantum harmonic oscillators driven either by constant forces of different magnitudes or time-dependent driving forces. The expectation values of position for various combinations of mass, natural…

Quantum Physics · Physics 2022-11-22 Sohini Marik , Souvik Naskar , Shibaji Banerjee

On the base of a Feynman-Kac--type formula involving Poisson stochastic processes, recently a Monte Carlo algorithm has been introduced, which describes exactly the real- or imaginary-time evolution of many-body lattice quantum systems. We…

Other Condensed Matter · Physics 2011-07-19 Massimo Ostilli , Carlo Presilla

In quantum information theory, there is an explicit mapping between general unitary dynamics and Hermitian ground state eigenvalue problems known as the Feynman-Kitaev Clock. A prominent family of methods for the study of quantum ground…

Quantum Physics · Physics 2015-01-14 Jarrod R. McClean , Alán Aspuru-Guzik

The interaction and exchange-correlation contributions to the ground-state energy of an arbitrary many-electron system can be obtained from a spherical average of the wavevector-dependent diagonal structure factor (SF). We model the…

Materials Science · Physics 2015-06-25 R. Gaudoin , J. M. Pitarke

We evaluate imaginary time density-density correlation functions for a two-dimensional homogeneous electron gas using the phaseless auxiliary field quantum Monte Carlo method. We show that such methodology, once equipped with suitable…

Strongly Correlated Electrons · Physics 2015-09-04 M. Motta , D. E. Galli , S. Moroni , E. Vitali

The accurate theoretical description of the dynamic properties of correlated quantum many-body systems such as the dynamic structure factor $S(\mathbf{q},\omega)$ constitutes an important task in many fields. Unfortunately, highly accurate…

Statistical Mechanics · Physics 2023-03-08 Tobias Dornheim , Zhandos Moldabekov , Panagiotis Tolias , Maximilian Böhme , Jan Vorberger

The Markov chain Monte Carlo (MCMC) method is used to evaluate the imaginary-time path integral of a quantum oscillator with a potential that includes both a quadratic term and a quartic term whose coupling is varied by several orders of…

Computational Physics · Physics 2020-08-27 Shikhar Mittal , Marise J. E. Westbroek , Peter R. King , Dimitri D. Vvedensky

The problem of calculating real-time correlation functions is formulated in terms of an imaginary-time partial differential equation. The latter is solved analytically for the perturbed harmonic oscillator and compared with the known exact…

Statistical Mechanics · Physics 2007-05-23 P. E. Kornilovitch

We have used the variational and diffusion quantum Monte Carlo methods to calculate the energy, pair correlation function, static structure factor, and momentum density of the ground state of the two-dimensional homogeneous electron gas. We…

Mesoscale and Nanoscale Physics · Physics 2010-03-02 N. D. Drummond , R. J. Needs
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