Periodic magnetization structures generated by transverse spin-current in magnetic nanowires

TL;DR

This paper theoretically investigates how strong perpendicular spin-polarized currents induce periodic magnetization structures in magnetic nanowires, revealing critical behaviors and hysteresis effects through analytical and simulation methods.

Contribution

It introduces a comprehensive theoretical analysis of current-induced magnetization structures in nanowires, including critical parameters and hysteresis phenomena, using Landau-Lifshitz-Slonczewski phenomenology.

Findings

Magnetization remains uniform at small currents but inclines with increasing current.

Periodic multidomain structures form in thicker wires at high currents.

Hysteresis observed during saturation process in thick wires.

Abstract

Magnetization behavior of long nanowires with square cross-section under influence of strong perpendicular spin-polarized current is studied theoretically. The study is based on Landau-Lifshitz-Slonczewski phenomenology. In the no current case the wire is magnetized uniformly along its axis. For small currents the wire magnetization remains uniform but it inclines with respect to the wire axis within the plane perpendicular to the current direction. With the current increasing the inclination angle increases up to the maximum value $\pi/4$. Further current increase leads either to saturation or to stable periodic multidomain structure depending on the wire thickness. For thick wires a hysteresis is observed in the saturation process under the action of current. All critical parameters of the current induced magnetization behavior are determined theoretically. The study is carried out both analytically and using micromagnetic simulations.