Bose one-component plasma in 2D: a Monte Carlo study

TL;DR

This study uses Quantum Monte Carlo simulations to investigate the low-temperature superfluid properties of a 2D Bose plasma with Coulomb interactions, revealing a superfluid phase persisting at high densities beyond previous estimates of crystallization.

Contribution

First comprehensive Monte Carlo analysis of 2D charged Bose fluid showing superfluidity persists near the Wigner crystallization threshold.

Findings

Superfluid ground state observed up to $r_s$=70.

No evidence of re-entrant crystalline phase or metastable bubbles.

Superfluid transition temperature weakly depends on density.

Abstract

The low-temperature properties of a 2D Bose fluid of charged particles interacting through a 1/r potential, moving in the presence of a uniform neutralizing background, is studied by Quantum Monte Carlo simulations. We make use of the Modified Periodic Coulomb potential formalism to account for the long-range character of the interaction, and explore a range of density corresponding to average interparticle separation $1 \le r_s\le 80$. We report numerical results based on simulations of system comprising up to 2304 particles. We find a superfluid ground state for $r_s$ as large as 70, i.e., significantly above the most recent numerical estimate of the Wigner crystallization threshold, which we estimate at $r_W \approx 71$. Furthermore, no thermally re-entrant crystalline phase nor any evidence of metastable bubbles is observed near the transition, in contrast with a previous theoretical study in which quantum statistics was neglected. The computed superfluid transition temperature depends remarkably weakly on density.