Perturbative calculation of the spin-wave dispersion in a disordered double-exchange model

TL;DR

This paper develops a perturbative approach to analyze how disorder affects spin-wave dispersion in a one-dimensional double-exchange model, revealing anomalous gapped-like behavior at the Fermi wavevector.

Contribution

It introduces a perturbation theory method to calculate spin-wave dispersion in disordered double-exchange systems, focusing on one-dimensional cases.

Findings

Disorder causes anomalous gapped-like behavior at the Fermi wavenumber.

Next-leading order calculations improve understanding of disorder effects.

The study provides insights into spin dynamics in disordered magnetic systems.

Abstract

We study the spin-wave dispersion of localized spins in a disordered double-exchange model using the perturbation theory with respect to the strength of the disorder potential. We calculate the dispersion upto the next-leading order, and extensively examine the case of one-dimension. We show that in that case, disorder yields anomalous gapped-like behavior at the Fermi wavenumber of the conduction electrons.