Effect of Transverse Magnetic Field on Dynamics of Current Driven Domain Wall Motion in the Presence of Spin-Hall Effect

TL;DR

This paper theoretically investigates how a transverse magnetic field influences the dynamics of current-driven domain walls in a bi-layer with spin-Hall effect, revealing effects on velocity, width, and polarity switching thresholds.

Contribution

It provides analytical expressions for domain wall velocity and width considering spin-Hall effect and magnetic field, highlighting their impact on domain wall dynamics.

Findings

Polarity switching occurs only above a threshold current density.

Transverse magnetic field increases the threshold current density.

Saturated velocity at threshold current density is enhanced by the magnetic field.

Abstract

Theoretically, we study the dynamics of a current induced domain wall in the bi-layer structure consists of a ferromagnetic layer and a non-magnetic metal layer with strong spin-orbit coupling in the presence of spin-Hall effect. The analytical expressions for the velocity and width of the domain wall interms of excitation angle are obtained by solving the Landau-Lifshitz-Gilbert equation with adiabatic, nonadiabatic and spin Hall effect-spin transfer torques using Schryers and Walker's method. Numerical results show that the occurance of polarity switching in the domain wall is observed only above the threshold current density. The presence of transverse magnetic field along with spin Hall effect-spin transfer torque enchances the value of the threshold current density, and the corresponding saturated velocity at the threshold current density is also increased.