Micromagnetic prediction strain and current co-mediated spindynamics in skyrmion-based spin-torque nano-oscillator

Abstract

Abstract In this article, we theoretically investigate the influence of strain on the oscillation frequency characteristics of a skyrmion-based spin-torque nano-oscillator (STNO) using micromagnetic simulations. The system consists of an ultrathin nanopillar magnetic film with interfacial Dzyaloshinskii–Moriya interactions and a ring-shaped region to offer a tunable spatial strain source. The applied strain gives rise to an extra effective field in the magnetic film through magnetoelastic coupling and forms a strong confined potential for skyrmion dynamics. Our simulation results show that the operation frequency of the STNO can be effectively modulated by the strain. Furthermore, we introduce a simplified analytical expression of the skyrmion gyration dynamics to explain the micromagnetic simulation results. Our results will be useful in the development of wide-range frequency-tunable microwave emitters and frequency-shift keying for wireless communication.