Magnon softening in a ferromagnetic monolayer: a first-principles spin dynamics study

TL;DR

This study combines first-principles calculations and atomistic spin dynamics to analyze magnon softening in a ferromagnetic Fe monolayer, aligning well with experimental data and highlighting the importance of finite temperature effects.

Contribution

It demonstrates that atomistic spin dynamics effectively captures magnon softening and finite temperature effects, challenging previous limitations of density functional theory models.

Findings

Magnon spectrum softening observed in Fe/W(110) monolayer

Finite temperature effects significantly influence spin dynamics

Atomistic spin dynamics accurately reproduce experimental dispersion data

Abstract

We study the Fe/W(110) monolayer system through a combination of first principles calculations and atomistic spin dynamics simulations. We focus on the dispersion of the spin waves parallel to the [001] direction. Our results compare favorably with the experimental data of Prokop et al. [Phys. Rev. Lett. 102, 177206], and correctly capture a drastic softening of the magnon spectrum, with respect to bulk bcc Fe. The suggested shortcoming of the itinerant electron model, in particular that given by density functional theory, is refuted. We also demonstrate that finite temperature effects are significant, and that atomistic spin dynamics simulations represent a powerful tool with which to include these.