Injection locking at zero field in two free layer spin-valves

TL;DR

This paper predicts that spin-transfer torque oscillators with hybrid spin-valves can achieve injection locking at zero magnetic field, enabling potential applications in high-speed frequency division and phase-locked-loop systems.

Contribution

It introduces a novel approach for injection locking in spin-valves with two free layers and perpendicular polarizers at zero bias field, expanding potential applications.

Findings

Locking regions near 0.5f0, f0, and 2f0 frequencies identified.

System promising for high-speed frequency dividers and multipliers.

Potential for phase-locked-loop demodulators demonstrated.

Abstract

This paper predicts the possibility to achieve synchronization (via injection locking to a microwave current) of spin-transfer torque oscillators based on hybrid spin-valves composed by two free layers and two perpendicular polarizers at zero bias field. The locking regions are attained for microwave frequency near 0.5f0, f0, and 2f0 where f0 is the input oscillator frequency. Those properties make this system promising for applications, such as high-speed frequency dividers and multipliers, and phase-locked-loop demodulators.