Synchronization of an Antiferromagnetic Josephson-like Oscillator with an External AC Signal

Abstract

Magnetization dynamics in a highly nonlinear antiferromagnetic Josephson-like spintronic oscillator under the action of DC and AC signals is studied theoretically and numerically, and the regime of the oscillator synchronization to an external AC signal has been found and investigated. We revealed that the synchronization bandwidth of the oscillator substantially depends not only on the external force amplitude (which is typical), but also on the oscillator nonlinearity. This behavior arises from the highly nonlinear nature of the considered system. Our theoretical and numerical analyses show that the generation frequency of the oscillator depends on the applied electric DC current in a nonlinear way. Thus, the correct choice of the working point characterized by some particular value of the nonlinearity coefficient is important for the considered system to work properly, and it can be used for maximizing the oscillator synchronization bandwidth. Obtained results are important for the further development of antiferromagnetic terahertz-frequency spintronic oscillators and their applications. The developed formalism and numerical simulations can also be used for the description of strongly nonlinear non-isochronous oscillators of any nature.