@Article{CiCP-38-1355, author = {Ye , Xuda and Zhou , Zhennan}, title = {Dimension-Free Ergodicity of Path Integral Molecular Dynamics}, journal = {Communications in Computational Physics}, year = {2025}, volume = {38}, number = {5}, pages = {1355--1388}, abstract = {

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 $\Gamma$ 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 $N$.

}, issn = {1991-7120}, doi = {https://doi.org/10.4208/cicp.OA-2024-0004}, url = {http://global-sci.org/intro/article_detail/cicp/24460.html} }