Kinetics of phase ordering with topological textures

TL;DR

This paper investigates how topological textures influence phase ordering in a 2D nonlinear sigma model, revealing two decay mechanisms and complex scaling behavior due to multiple evolving length scales.

Contribution

It identifies and characterizes two distinct decay mechanisms of topological textures during phase ordering, highlighting the complex dynamics and scaling violations involved.

Findings

Early-time dominance of topological charge annihilation

Later-time significance of texture unwinding

Strong violation of dynamical scaling due to multiple length scales

Abstract

We study the role played by topological textures and antitextures during the phase ordering of a two-dimensional system described by the discretised nonlinear O(3) sigma model with purely dissipative dynamics. We identify and characterise two distinct mechanisms for the decay of the order parameter variations --- single texture unwinding, and topological charge annihilation. Our results show that while at early times after the quench, the annihilation process dominates, the unwinding processes become of comparable importance at later times. We calculate the correlations in the order parameter and in the topological charge density, and show that dynamical scaling is strongly violated due to the occurence of multiple length scales growing differently in time.