Domain wall attraction and repulsion during spin-torque-induced coherent motion

TL;DR

This paper investigates how current-induced forces cause magnetic domain walls to attract or repel each other, leading to equilibrium spacings that depend on current magnitude, with implications for magnetic device control.

Contribution

It introduces a calculation of domain wall interactions during coherent motion, revealing separation-dependent forces and equilibrium states influenced by current strength.

Findings

Domain walls exhibit attraction at large separations.

Domain walls repel at short distances.

An equilibrium spacing depends on current magnitude.

Abstract

We calculate the interaction between two magnetic domain walls during their current-induced motion. This interaction produces a separation-dependent resistance and also a differential velocity, causing domains in motion to experience an effective attraction at large separations and an effective repulsion at short separations. In an intermediate range of currents the two domain walls will reach a natural equilibrium spacing that depends on the magnitude of the current flowing through the material.