Numerical Study of a Superconducting Glass Model

TL;DR

This study investigates the behavior of a superconducting glass model using a zero-temperature renormalization group approach, revealing the effects of disorder in two and three dimensions and challenging previous theories.

Contribution

It applies a domain wall renormalization group method to analyze disorder effects in a superconducting glass model across dimensions, providing new insights into its phase behavior.

Findings

Weak disorder is marginal in 2D and likely irrelevant in 3D.

Strong disorder flows to a non-superconducting fixed point in 2D.

Strong disorder leads to a superconducting glass in 3D.

Abstract

An XY model with random phase shifts as a model for a superconducting glass is studied in two and three dimensions by a zero temperature domain wall renormalization group which allows one to follow the flows of both the coupling constant and the disorder strength with increasing length scale. Weak disorder is found to be marginal in two and probably irrelevant in three dimensions. For strong disorder the flow is towards a non-superconducting gauge glass fixed point in 2d and a superconducting glass in 3d. Our results are in agreement with recent analytic theory and are inconsistent with earlier predictions of a re-entrant transition to a disordered phase at very low temperature and with the loss of superconductivity for any finite amount of disorder.