Electric field control of magnons in magnetic thin films: ab initio predictions for 2D metallic heterostructures

TL;DR

This study uses ab initio calculations to show how external electric fields can control magnon properties in 2D magnetic heterostructures, with effects depending on substrate and layer thickness.

Contribution

It provides the first ab initio predictions of electric field effects on magnons in 2D metallic heterostructures, highlighting substrate and thickness dependencies.

Findings

Electric fields can significantly modify magnon lifetimes.

Magnon energy gaps vary with external electric field.

Substrate influences the sensitivity of magnon spectra.

Abstract

We explore possibilities for control of magnons in two-dimensional heterostructures by an external electric field acting across a dielectric barrier. By performing ab-initio calculations for a Fe monolayer and a Fe bilayer, both suspended in vacuum and deposited on Cu(001), we demonstrate that external electric field can significantly modify magnon lifetimes and that these changes can be related to field-induced changes in the layer-resolved Bloch spectral functions. For systems with more magnon dispersion branches, the gap between high- and low-energy eigenmodes varies with the external field. These effects are strongly influenced by the substrate. Considerable variability in how the magnon spectra are sensitive to the external electric field can be expected, depending on the substrate and on the thickness of the magnetic layer.