Pressure induced orientational glass phase in molecular para-hydrogen

TL;DR

This paper presents a theoretical model predicting an orientational glass transition in solid molecular para-hydrogen and ortho-deuterium under high pressure, using spin-glass theory concepts.

Contribution

It introduces a novel theoretical framework for understanding orientational glass phases in molecular hydrogen and deuterium under pressure, linking to experimental phase diagrams.

Findings

Predicts the existence of an orientational glass phase under high pressure.

Connects the glass transition to the II' phase in hydrogen phase diagram.

Uses spin-glass theory to model molecular orientation disorder.

Abstract

We propose a theoretical description of possible orientational glass transition in solid molecular para-hydrogen and ortho-deuterium under pressure supposing that they are mixtures of J=0 and J=2 states of molecules. The theory uses the basic concepts and methods of standard spin-glass theory. We expect our orientational glass to correspond the II' phase of the high pressure hydrogen phase diagram.