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 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.

Field-free self-oscillation of magnetization enabled by the fieldlike spin-orbit torque

“…It seems to be naively believed that a timedependent current should provide more adjustability. By an appropriate linearization, Bondarenko and Sherman [51] decomposed the magnetization dynamics as a superposition of the in-plane precession and outof-plane nutation and confirmed that the pulse shape and magnitude of the alternating current can control the magnetization oscillation and switching. From an application viewpoint, a time-dependent current favors improving energy efficiency.…”

Significant Modulation of Vortex Resonance Spectra in a Square-Shape Ferromagnetic Dot

“…The dynamic properties of magnetic materials or devices are interesting research areas because of their vast frequency tuning range from several megahertz to gigahertz and even terahertz [1][2][3][4]. The total energy of a ferromagnetic unit is determined by the competition among the exchange field, demagnetization field, external field and anisotropic field etc.…”