Path integral molecular dynamics simulations for Green's function in a system of identical bosons

TL;DR

This paper extends path integral molecular dynamics to compute Green's functions in bosonic systems, enabling analysis of momentum distributions and phase transitions like the Berezinskii-Kosterlitz-Thouless transition.

Contribution

The work develops a novel PIMD-based method to calculate Green's functions and momentum distributions in interacting bosonic systems, including phase transition analysis.

Findings

Successfully computed Green's functions and momentum distributions.

Applied method to study BKT transition near critical temperature.

Demonstrated effectiveness in large bosonic systems.

Abstract

Path integral molecular dynamics (PIMD) has been successfully applied to perform simulations of large bosonic systems in a recent work (Hirshberg et al., PNAS, 116, 21445 (2019)). In this work we extend PIMD techniques to study Green's function for bosonic systems. We demonstrate that the development of the original PIMD method enables us to calculate Green's function and extract momentum distribution from our simulations. We also apply our method to systems of identical interacting bosons to study Berezinskii-Kosterlitz-Thouless transition around its critical temperature.