Theory for Quantum Spin and Vortex Glasses

TL;DR

This paper develops a theoretical model for quantum vortex glasses with disorder, revealing phase diagrams with superfluid and glass regions, and predicts experimental signatures of glass transitions.

Contribution

It introduces a comprehensive theory for quantum vortex glasses with site and coupling disorder, linking to XY spin glasses and bosons in random media.

Findings

Phase diagram includes superfluid, Weak Glass, and Strong Glass regions.

Strong Glass transition lacks divergence in non-linear susceptibility.

Model relates to experimental observations in disordered quantum systems.

Abstract

We develop a theory for the quantum vortex glass, with both the coupling strengths and the site energies disordered. This model is closely related to XY spin glasses and bosons in random media. For properly chosen distributions of the site disorder the phase diagram consists of a superfluid phase, and Weak and Strong Glass regions, dominated by long range and local fluctuations, respectively. The most direct experimental manifestation of the Strong Glass transition is the lack of divergence of the corresponding non-linear susceptibility.