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Main Authors: Ye, Xuda, Zhou, Zhennan
Format: Preprint
Published: 2023
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Online Access:https://arxiv.org/abs/2307.06510
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author Ye, Xuda
Zhou, Zhennan
author_facet Ye, Xuda
Zhou, Zhennan
contents The quantum thermal average plays a central role in describing the thermodynamic properties of a quantum system. Path integral molecular dynamics (PIMD) is a prevailing approach for computing quantum thermal averages by approximating the quantum partition function as a classical isomorphism on an augmented space, enabling efficient classical sampling, but the theoretical knowledge of the ergodicity of the sampling is lacking. Parallel to the standard PIMD with $N$ ring polymer beads, we also study the Matsubara mode PIMD, where the ring polymer is replaced by a continuous loop composed of $N$ Matsubara modes. Utilizing the generalized $Γ$ calculus, we prove that both the Matsubara mode PIMD and the standard PIMD have uniform-in-$N$ ergodicity, i.e., the convergence rate towards the invariant distribution does not depend on the number of modes or beads $N$.
format Preprint
id arxiv_https___arxiv_org_abs_2307_06510
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Dimension-free Ergodicity of Path Integral Molecular Dynamics
Ye, Xuda
Zhou, Zhennan
Numerical Analysis
Probability
Computational Physics
Quantum Physics
37A30, 82B31, 81S40
The quantum thermal average plays a central role in describing the thermodynamic properties of a quantum system. Path integral molecular dynamics (PIMD) is a prevailing approach for computing quantum thermal averages by approximating the quantum partition function as a classical isomorphism on an augmented space, enabling efficient classical sampling, but the theoretical knowledge of the ergodicity of the sampling is lacking. Parallel to the standard PIMD with $N$ ring polymer beads, we also study the Matsubara mode PIMD, where the ring polymer is replaced by a continuous loop composed of $N$ Matsubara modes. Utilizing the generalized $Γ$ calculus, we prove that both the Matsubara mode PIMD and the standard PIMD have uniform-in-$N$ ergodicity, i.e., the convergence rate towards the invariant distribution does not depend on the number of modes or beads $N$.
title Dimension-free Ergodicity of Path Integral Molecular Dynamics
topic Numerical Analysis
Probability
Computational Physics
Quantum Physics
37A30, 82B31, 81S40
url https://arxiv.org/abs/2307.06510