Injection locking of antiferromagnetic spin Hall nano-oscillators to a microwave current

Abstract

Antiferromagnetic spin Hall nano-oscillators (ASHNOs), attributed to the spin Hall effect and spin transfer torque, have been extensively studied over the past few years owing to their potentials for application as devices in the THz frequency range. However, low output power of ASHNOs is a main obstacle to overcome for practical application. In this regard, we investigate the injection locking of ASHNOs to a microwave current. In order to describe the magnetization dynamics of ASHNOs, we employ a numerical macrospin model expressed by Landau-Lifshitz-Gilbert-Slonczewki equation. We found that the injection locking of ASHNO is achieved by the microwave current whose frequency is in the THz range, and the locking range depends on the amplitude of the injected microwave current. We look forward to an experimental confirmation of these results with existing experimental techniques.