Phase ordering in 3d disordered systems

TL;DR

This paper investigates how disorder affects the rate of phase ordering in 3D Ising models, revealing a non-monotonous relationship between dilution and growth speed, with a novel increase beyond a critical dilution.

Contribution

It demonstrates a non-monotonous dependence of domain growth speed on dilution in 3D disordered systems, extending previous 2D findings with a renormalization-group interpretation.

Findings

Growth speed decreases with initial dilution increase

Beyond a critical dilution, growth speed increases again

Results support a non-monotonous disorder effect in 3D systems

Abstract

We study numerically the phase-ordering kinetics of the site-diluted and bond-diluted Ising models after a quench from an infinite to a low temperature. We show that the speed of growth of the ordered domain's size is non-monotonous with respect to the amount of dilution $D$: Starting from the pure case $D=0$ the system slows down when dilution is added, as it is usually expected when disorder is introduced, but only up to a certain value $D^*$ beyond which the speed of growth raises again. We interpret this counterintuitive fact in a renormalization-group inspired framework, along the same lines proposed for the corresponding two-dimensional systems, where a similar pattern was observed.