Injection locking in DC-driven spintronic vortex oscillators via surface acoustic wave modulation

TL;DR

This paper explores how surface acoustic waves can be used to synchronize spintronic vortex oscillators, enhancing their signal control for applications in spin wave generation and neuromorphic computing.

Contribution

It introduces a simplified theoretical model and micromagnetic simulations to demonstrate injection locking of vortex STOs via surface acoustic waves, highlighting the role of vortex deformations.

Findings

Locking bandwidth depends on SAW amplitude.

External field amplitude and direction influence locking.

The study provides insights for low-power STO network synchronization.

Abstract

Control of the microwave signal generated by spin-transfer torque oscillators (STOs) is crucial for their applications in spin wave generation and neuromorphic computing. This study investigates injection locking of a DC-driven vortex STO using surface acoustic waves (SAWs) to enhance the STO's signal and allow for its synchronization with external inputs. We employ a simplified model based on Thiele's formalism and highlight the role of vortex deformations in achieving injection locking. Micromagnetic simulations are conducted to validate our theoretical predictions, revealing how the locking bandwidth depends on SAW amplitude, as well as on the amplitude and direction of an applied external field. Our findings are pivotal for advancing experimental research and developing efficient low-power synchronization methods for large-scale STO networks.