Superfluidity of metastable bulk glass para-hydrogen at low temperature

TL;DR

This study investigates the potential for superfluidity in metastable bulk para-hydrogen by using advanced simulation techniques to prevent crystallization and identify superfluid transition temperatures around 1 K.

Contribution

It demonstrates how to simulate metastable liquid para-hydrogen and identifies its superfluid transition temperature using Path Integral Monte Carlo methods.

Findings

Superfluid transition occurs near 1 K in metastable p-H2.

Metastable liquid phase exhibits a measurable superfluid fraction.

Zero-temperature properties of metastable p-H2 are characterized and compared to solid phase.

Abstract

Molecular para-hydrogen has been proposed theoretically as a possible candidate for superfluidity, but the eventual superfluid transition is hindered by its crystallization. In this work, we study a metastable non crystalline phase of bulk p-H2 by means of the Path Integral Monte Carlo method in order to investigate at which temperature this system can support superfluidity. By choosing accurately the initial configuration and using a non commensurate simulation box, we have been able to frustrate the formation of the crystal in the simulated system and to calculate the temperature dependence of the one-body density matrix and of the superfluid fraction. We observe a transition to a superfluid phase at temperatures around 1 K. The limit of zero temperature is also studied using the diffusion Monte Carlo method. Results for the energy, condensate fraction, and structure of the metastable liquid phase at T=0 are reported and compared with the ones obtained for the stable solid phase.