Electron drag in ferromagnetic structures separated by an insulating interface

TL;DR

This paper investigates electron drag effects in ferromagnetic bilayers separated by an insulator, focusing on magnon-electron interactions and comparing magnon-induced drag to phonon-induced effects.

Contribution

It introduces a model for magnon-mediated electron drag in ferromagnetic layers and estimates its magnitude relative to phonon-induced drag.

Findings

Magnon-electron interactions induce measurable drag currents.

Magnon drag can be comparable to phonon-induced drag under certain conditions.

Theoretical estimates suggest significant magnon-mediated electron drag in ferromagnetic structures.

Abstract

We consider electron drag in a system of two ferromagnetic layers separated by an insulating interface. The source of it is expected to be magnon-electron interactions. Namely, we assume that the external voltage is applied to the "active" layer stimulating electric current through this layer. In its turn, the scattering of the current-carrying electrons by magnons leads to a magnon drag current within this layer. The 3-magnons interactions between magnons in the two layers (being of non-local nature) lead to magnon drag within the "passive" layer which, correspondingly, produce electron drag current via processes of magnon-electron scattering. We estimate the drag current and compare it to the phonon-induced one.