Magnonic momentum transfer force on domain walls confined in space

TL;DR

This paper investigates how confined magnons transfer linear momentum to Bloch domain walls, causing forces that can control domain wall motion, with implications for magnonic device engineering.

Contribution

It introduces a micromagnetic analysis of momentum transfer in confined geometries, revealing how dispersion mismatch leads to magnon reflection and momentum transfer to domain walls.

Findings

Magnon reflection occurs due to dispersion mismatch in confined geometries.

Momentum transfer can exert controllable forces on domain walls.

The study provides a basis for magnonic control of magnetic textures.

Abstract

Momentum transfer from incoming magnons to a Bloch domain wall is calculated using one dimensional continuum micromagnetic analysis. Due to the confinement of the wall in space, the dispersion relation of magnons is different from that of a single domain. This mismatch of dispersion relations can result in reflection of magnons upon incidence on the domain wall, whose direct consequence is a transfer of momentum between magnons and the domain wall. The corresponding counteraction force exerted on the wall can be used for the control of domain wall motion through magnonic linear momentum transfer, in analogy with the spin transfer torque induced by magnonic angular momentum transfer.