English
Related papers

Related papers: Path integral simulation of exchange interactions …

200 papers

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

We present a method for performing path integral molecular dynamics (PIMD) simulations for fermions and address its sign problem. PIMD simulations are widely used for studying many-body quantum systems at thermal equilibrium. However, they…

Chemical Physics · Physics 2020-05-07 Barak Hirshberg , Michele Invernizzi , Michele Parrinello

We explore exchange coupling of a pair of spins in a double dot and in an optical lattice. Our algorithm uses the frequency of exchanges in a bosonic path integral, evaluated with Monte Carlo. This algorithm is simple enough to be a "black…

Strongly Correlated Electrons · Physics 2010-07-27 Lei Zhang , Matthew Gilbert , Jesper Pedersen , John Shumway

A simple algorithm is described to sample permutations of identical particles in Path Integral Monte Carlo (PIMC) simulations of continuum many-body systems. The sampling strategy illustrated here is fairly general, and can be easily…

Computational Physics · Physics 2009-11-11 Massimo Boninsegni

The uniform electron gas (UEG) at finite temperature is of high current interest due to its key relevance for many applications including dense plasmas and laser excited solids. In particular, density functional theory heavily relies on…

Strongly Correlated Electrons · Physics 2016-01-15 Tobias Dornheim , Tim Schoof , Simon Groth , Alexey Filinov , Michael Bonitz

To account for the interference effects of the Coulomb and exchange interactions of electrons a new path integral representation of the density matrix has been developed in the canonical ensemble at finite temperatures. The developed…

Plasma Physics · Physics 2022-01-05 Vladimir Filinov , Pavel Levashov , Alexander Larkin

We present extensive \textit{ab initio} path integral Monte Carlo (PIMC) simulations of two-dimensional quantum dipole systems in a harmonic confinement, taking into account both Bose- and Fermi-statistics. This allows us to study the…

Computational Physics · Physics 2020-08-12 Tobias Dornheim

The strongly coupled electron liquid provides a unique opportunity to study the complex interplay of strong coupling with quantum degeneracy effects and thermal excitations. To this end, we carry out extensive \textit{ab initio} path…

Computational Physics · Physics 2020-02-05 Tobias Dornheim , Travis Sjostrom , Shigenori Tanaka , Jan Vorberger

We describe a method to evaluate electronic forces by Path Integral Monte Carlo (PIMC). Electronic correlations, as well as thermal effects, are included naturally in this method. For fermions, a restricted approach is used to avoid the…

Condensed Matter · Physics 2009-10-31 Fenghua Zong , D. M. Ceperley

We review the path integral method wherein quantum systems are mapped with Feynman's path integrals onto a classical system of "ring-polymers" and then simulated with the Monte Carlo technique. Bose or Fermi statistics correspond to…

Condensed Matter · Physics 2010-07-27 J. Shumway , D. M. Ceperley

Electron transfer (ET) across molecular chains including an impurity is studied based on a recently improved real-time path integral Monte Carlo (PIMC) approach [J. Chem. Phys. {\bf 121}, 12696 (2004)]. The reduced electronic dynamics is…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Lothar Muehlbacher , Joachim Ankerhold

Mean-field molecular dynamics based on path integrals is used to approximate canonical quantum observables for particle systems consisting of nuclei and electrons. A computational bottleneck is the sampling from the Gibbs density of the…

Numerical Analysis · Mathematics 2023-11-30 Xin Huang , Petr Plechac , Mattias Sandberg , Anders Szepessy

We present a hybrid Path Integral Monte Carlo (hPIMC) algorithm to calculate real-time quantum thermal correlation functions and demonstrate its application to open quantum systems. The hPIMC algorithm leverages the successes of classical…

Quantum Physics · Physics 2025-06-12 Elliot C. Eklund , Nandini Ananth

Accurate thermodynamic simulations of correlated fermions using path integral Monte Carlo (PIMC) methods are of paramount importance for many applications such as the description of ultracold atoms, electrons in quantum dots, and warm-dense…

Computational Physics · Physics 2021-02-03 Tobias Dornheim , Michele Invernizzi , Jan Vorberger , Barak Hirshberg

Accurate ab initio calculations of 3d transition metal monoxide molecules have attracted extensive attention because of its relevance in physical and chemical science, as well as theoretical challenges in treating strong electron…

Strongly Correlated Electrons · Physics 2021-11-02 Tonghuan Jiang , Yilin Chen , Nikolay Bogdanov , Enge Wang , Ali Alavi , Ji Chen

An improved real-time quantum Monte Carlo procedure is presented and applied to describe the electronic transfer dynamics along molecular chains. The model consists of discrete electronic sites coupled to a thermal environment which is…

Chemical Physics · Physics 2009-11-10 L. Muehlbacher , J. Ankerhold , C. Escher

We investigate the thermal expansion of crystalline SiO$_2$ in the $\beta$-- cristobalite and the $\beta$-quartz structure with path integral Monte Carlo (PIMC) techniques. This simulation method allows to treat low-temperature quantum…

Statistical Mechanics · Physics 2009-10-31 Chr. Rickwardt , P. Nielaba , M. H. Müser , K. Binder

The results of analytical approximations and extensive calculations based on a path integral Monte Carlo (PIMC) scheme are presented. A new (direct) PIMC method allows for a correct determination of thermodynamic properties such as energy…

Astrophysics · Physics 2007-05-23 V. Filinov , M. Bonitz , D. Kremp , W. -D. Kraeft , V. Fortov

The quantum theory of the Friedmann cosmological model with dust and cosmological constant ($\Lambda$) is not exactly solvable analytically. We apply Path Integral Monte Carlo (PIMC) techniques to study its quantum dynamics using the…

General Relativity and Quantum Cosmology · Physics 2020-09-10 Masooma Ali , Syed Moeez Hassan , Viqar Husain

A Path Integral Monte Carlo method is used to investigate the thermodynamics of nuclear like systems. Systems composed of bosons or fermions interracting via a Lennard-Jones potential with periodic boundary conditions were simulated and the…

Nuclear Theory · Physics 2010-09-02 A. H. Raduta