Large amplitude oscillation of magnetization in spin-torque oscillator stabilized by field-like torque

TL;DR

This paper theoretically investigates how field-like torque influences large amplitude magnetization oscillations in spin-torque oscillators, highlighting its role in stabilizing steady precession through energy balance.

Contribution

It introduces a theoretical framework incorporating field-like torque to explain steady precession in spin-torque oscillators with specific magnetic configurations.

Findings

Field-like torque is crucial for achieving steady magnetization precession.

The theory aligns well with numerical simulations based on the Landau-Lifshitz-Gilbert equation.

Large amplitude oscillations are stabilized by the balance of spin torque energy and damping.

Abstract

Oscillation frequency of spin torque oscillator with a perpendicularly magnetized free layer and an in-plane magnetized pinned layer is theoretically investigated by taking into account the field-like torque. It is shown that the field-like torque plays an important role in finding the balance between the energy supplied by the spin torque and the dissipation due to the damping, which results in a steady precession. The validity of the developed theory is confirmed by performing numerical simulations based on the Landau-Lifshitz-Gilbert equation.