Theory of the superglass phase

TL;DR

This paper introduces a three-dimensional bosonic model that exhibits a superglass phase, characterized by simultaneous superfluidity and amorphous structure, and provides exact and approximate analyses of its properties.

Contribution

The authors present a novel bosonic model demonstrating the superglass phase and establish a mapping to classical hard sphere systems for quantitative analysis.

Findings

Identification of the superglass phase in the model

Quantitative analysis of static and dynamic correlations

Characterization of the quantum phase transition between superfluid and superglass

Abstract

A superglass is a phase of matter which is characterized at the same time by superfluidity and a frozen amorphous structure. We introduce a model of interacting bosons in three dimensions that displays this phase unambiguously and that can be analyzed exactly or using controlled approximations. Employing a mapping between quantum Hamiltonians and classical Fokker-Planck operators, we show that the ground state wavefunction of the quantum model is proportional to the Boltzmann measure of classical hard spheres. This connection allows us to obtain quantitative results on static and dynamic quantum correlation functions. In particular, by translating known results on the glassy dynamics of Brownian hard spheres we work out the properties of the superglass phase and of the quantum phase transition between the superfluid and the superglass phase.