Criticality of relaxation in dislocation systems

TL;DR

This study uses 2D simulations to explore how dislocation systems relax, revealing universal critical behavior driven by velocity distribution scaling, with implications for understanding glassy material dynamics.

Contribution

It demonstrates that relaxation in dislocation systems exhibits criticality due to velocity distribution scaling, a novel insight into dislocation dynamics.

Findings

Power-law decay observed in physical quantities

Scaling breaks down at a system size-dependent cut-off time

Absence of intrinsic relaxation time indicates criticality

Abstract

Relaxation processes of dislocation systems are studied by two-dimensional dynamical simulations. In order to capture generic features, three physically different scenarios were studied and power-law decays found for various physical quantities. Our main finding is that all these are the consequence of the underlying scaling property of the dislocation velocity distribution. Scaling is found to break down at some cut-off time increasing with system size. The absence of intrinsic relaxation time indicates that criticality is ubiquitous in all states studied. These features are reminiscent to glassy systems, and can be attributed to the inherent quenched disorder in the position of the slip planes.