The influence of structure disorder on mean atomic momentum fluctuations and a spin-wave spectrum

TL;DR

This paper explores how structural disorder affects atomic momentum fluctuations and spin-wave spectra, using mean-field and Green function methods to analyze excitation energies and damping in disordered magnetic systems.

Contribution

It introduces a theoretical framework linking structure disorder to atomic and spin dynamics, including new insights into spin-wave behavior in disordered environments.

Findings

Derived relations between atomic momentum and density fluctuations.

Obtained equations for spin excitation energy and damping.

Discussed anomalous behavior of spin-wave stiffness constant.

Abstract

The relation between atomic momenta fluctuations and density fluctuations is obtained in frames of mean-field approximation. Using two-time temperature Green functions within Tyablikov approximation the equations for spin excitation energy and damping are obtained. The asymptotics of energy and damping in the long-wave limit are investigated and the anomalous behaviour of spin-wave stiffness constant is discussed.