Low temperature phase diagram of condensed para-Hydrogen in two dimensions

TL;DR

This study uses Path Integral Monte Carlo simulations to explore the low-temperature phase diagram of two-dimensional condensed para-Hydrogen, revealing a stable crystalline phase with no metastable liquid, and melting near 7 K.

Contribution

First detailed simulation of 2D para-Hydrogen phase diagram at low temperatures showing crystal stability and melting behavior.

Findings

System remains solid down to spinodal density

No metastable liquid phase observed

Crystal melts at approximately 7 K

Abstract

Extensive Path Integral Monte Carlo simulations of condensed para-Hydrogen in two dimensions at low temperature have been carried out. In the zero temperature limit, the system is a crystal at equilibrium, with a triangular lattice structure. No metastable liquid phase is observed, as the system remains a solid down to the spinodal density, and breaks down into solid clusters at lower densities. The equilibrium crystal is found to melt at a temperature close to 7 K.