Current-Induced Magnetic Domain-Wall Motion by Spin Transfer Torque: Collective Coordinate Approach with Domain-Wall Width Variation

TL;DR

This paper develops a theoretical model for current-induced magnetic domain-wall motion, incorporating domain-wall width variation, and shows how this affects the critical current needed for motion.

Contribution

The study extends the collective coordinate approach to include domain-wall width variation, providing new insights into the critical current for domain-wall motion.

Findings

Width variation influences the critical current.

The extended model improves understanding of domain-wall dynamics.

The approach offers a more comprehensive theoretical framework.

Abstract

The spin transfer torque generated by a spin-polarized current can induce the shift of the magnetic domain-wall position. In this work, we study theoretically the current-induced domain-wall motion by using the collective coordinate approach [Gen Tatara and Hiroshi Kohno, Phys. Rev. Lett. 92, 86601 (2004)]. The approach is extended to include not only the domain-wall position and the polarization angle changes but also the domain-wall width variation. It is demonstrated that the width variation affects the critical current.