Self-oscillations induced by self-induced torque in magnetic double tunnel junction

TL;DR

This paper investigates how self-induced torque can generate GHz-range self-oscillations in magnetic double tunnel junctions, highlighting the importance of self-induced torque and field-like torque in controlling oscillation properties.

Contribution

It demonstrates through numerical analysis that self-induced torque is crucial for GHz oscillations in magnetic junctions and explores how field-like torque influences oscillation characteristics.

Findings

Self-induced torque is essential for GHz oscillations.

Frequency decreases with current without FLT, but increases with FLT presence.

Power and Q-factor increase with current and FLT strength.

Abstract

Self-oscillations of the magnetization due to self-induced torque (SIT) in a magnetic double tunnel junction that consists of perpendicularly polarized, pinned and free layers is investigated along with the field-like torque (FLT). The associated Landau-Lifshitz-Gilbert-Slonczewski equation is numerically analysed to exhibit the oscillations of magnetization driven by the current. From the numerical analysis, we show that the SIT is essential to generate oscillations in the order of GHz and without it the magnetization reaches steady state after exhibiting switching. Without FLT, the frequency of the oscillations decreases with the current while the power of oscillations increases. In the presence of the negative strength of the FLT the power spectral density confirms that the frequency, power and the Q-factor increase with the current. Also the tunability range and the rate at which the frequency enhances increase with the magnitude of the FLT.