Quantum Gibbs ensemble Monte Carlo

TL;DR

This paper introduces a quantum path integral Monte Carlo method that extends the classical Gibbs ensemble approach to quantum systems, effectively studying phase coexistence in strongly quantum regimes like 2D helium-4.

Contribution

It presents a novel quantum Gibbs ensemble Monte Carlo method capable of handling strong quantum delocalization and degeneracy effects, unlike previous methods.

Findings

Successfully applied to 2D helium-4 gas-superfluid transition

Handles strong quantum effects in degenerate regimes

Provides a viable simulation approach for quantum phase coexistence

Abstract

We present a path integral Monte Carlo method which is the full quantum analogue of the Gibbs ensemble Monte Carlo method of Panagiotopoulos to study the gas-liquid coexistence line of a classical fluid. Unlike previous extensions of Gibbs ensemble Monte Carlo to include quantum effects, our scheme is viable even for systems with strong quantum delocalization in the degenerate regime of temperature. This is demonstrated by an illustrative application to the gas-superfluid transition of $^4$He in two dimensions.