Current-induced domain wall motion with adiabatic spin torque only in cylindrical nanowires

TL;DR

This paper demonstrates that in cylindrical nanowires, adiabatic spin torque alone can drive domain wall motion, challenging the belief that nonadiabatic torque is necessary, and proposes an experimental method to measure spin current polarization.

Contribution

It shows that adiabatic spin torque alone suffices for domain wall motion in cylindrical nanowires, providing new insights into spin torque mechanisms.

Findings

Adiabatic spin torque can induce domain wall motion without nonadiabatic torque.

Proposed an experimental scheme to measure spin current polarization.

Challenged the common view on the necessity of nonadiabatic torque.

Abstract

We investigate current-driven domain wall (DW) propagation in magnetic nanowires in the framework of the modified Landau-Lifshitz-Gilbert equation with both adiabatic and nonadiabatic spin torque (NAST) terms. Contrary to the common opinion that NAST is indispensable for DW motion[1,2], we point out that adiabatic spin torque (AST) only is enough for current-driven DW motion in a cylindrical (uniaxial) nanowire. Apart from a discussion of the rigid DW motion from the energy and angular momentum viewpoint, we also propose an experimental scheme to measure the spin current polarization by combining both field and current driven DW motion in a flat (biaxial) wire.