Spin dynamics in the generalized ferromagnetic Kondo model for manganites

TL;DR

This paper calculates the spin susceptibility in a generalized ferromagnetic Kondo model for manganites, revealing a two-branch spin-wave spectrum and analyzing damping effects.

Contribution

It introduces a mean field approach to the model, showing the existence of acoustic and optic spin-wave branches and evaluating damping effects.

Findings

Two spin-wave branches identified: acoustic and optic.

Damping of acoustic spin-waves quantified.

Self-energy corrections influence the spin spectrum.

Abstract

Dynamical spin susceptibility is calculated for the generalized ferromagnetic Kondo model which describes itinerant $e_{g}$ electrons interacting with localized $t_{2g}$ electrons with antiferromagnetic coupling. The calculations done in the mean field approximation show that the spin-wave spectrum of the system in ferromagnetic state has two branches, acoustic and optic ones. Self-energy corrections to the spectrum are considered and the acoustic spin-wave damping is evaluated.