Imry-Ma disordered state induced by defects of "random local anisotropy" type in the system with O(n) symmetry

TL;DR

This paper investigates how defects of 'random local anisotropy' influence the emergence of the Imry-Ma disordered state in systems with O(n) symmetry, identifying conditions for disorder initiation and the role of anisotropy distribution.

Contribution

It discovers the conditions under which the Imry-Ma disordered state arises due to random local anisotropy defects in O(n) systems, highlighting the impact of anisotropy distribution.

Findings

Disordered state initiated when local anisotropy axes are nearly isotropic.

Higher anisotropy in axes distribution preserves long-range order.

Limiting degree of anisotropy distribution was quantitatively determined.

Abstract

For the system with the n-component order parameter (O(n)-model), conditions for initiation of the Imry-Ma disordered state resulting from the influence of defects of the "random local anisotropy" type were discovered. The initiation of such a state was shown to be possible if the distribution of local anisotropy axes directions in the order parameter space is nearly isotropic, and the limiting degree of the distribution anisotropy was found. For a higher anisotropy in the distribution of local axes directions, the long-range order in the system holds true even in the presence of defects of the given type.