Uniform magnetization dynamics of a submicron ferromagnetic disk driven by the spin–orbit coupled spin torque

Abstract

A simple model of magnetization dynamics in a ferromagnet/doped semiconductor hybrid structure with Rashba spin–orbit interaction (SOI), driven by an applied pulse of the electric field, is proposed. The electric current excited by the applied field is spin-polarized, due to the SOI and therefore it induces the magnetization rotation in the ferromagnetic layer via s-d exchange coupling. Magnetization dynamics dependence on the electric pulse shape and magnitude is analyzed for realistic values of the parameters. We show that it is similar to the dynamics of a damped nonlinear oscillator with the time-dependent frequency proportional to the square root of the applied electric field. The magnetization switching properties of an elliptic magnetic element are examined as a function of the applied field magnitude and direction.