Exchange Monte Carlo for continuous-space Path Integral Monte Carlo simulation

TL;DR

This paper introduces an Exchange Monte Carlo method with an exchange update scheme and Stochastic Potential Switching to improve the efficiency and accuracy of continuous-space Path Integral Monte Carlo simulations for bosonic systems, especially for global permutation-sensitive observables.

Contribution

The paper presents a novel EMC approach with exchange updates and SPS for efficient simulation of bosonic systems at finite temperature, addressing autocorrelation and long-range interaction challenges.

Findings

Significantly reduces autocorrelation times in PIMC simulations.

Enhances efficiency in handling long-range interatomic potentials.

Improves sampling of permutation effects in bosonic systems.

Abstract

We present a novel Exchange Monte Carlo (EMC) method designed for application in continuous-space Path Integral Monte Carlo (PIMC) simulations at finite temperature. Traditional PIMC methods for bosonic systems suffer from long autocorrelation times, particularly when measuring observables affected by particle permutations, such as the winding number. To address this issue, we introduce an exchange update scheme that facilitates replica transitions between different interaction regimes, significantly accelerating Monte Carlo dynamics-especially for global observables sensitive to permutation effects. Furthermore, we incorporate Stochastic Potential Switching (SPS) to efficiently decompose interactions, substantially enhancing computational efficiency for long-range interatomic pair potentials such as the Lennard-Jones and Aziz potentials.