We consider the excitation of large amplitude gyrotropic vortex core precession in a permalloy nanodisk by the torques originating from the in-plane microwave current flowing along the interface of the permalloy/${\mathrm{Bi}}_2{\mathrm{Se}}_3$ heterostructures, in which the huge charge-to-spin conversion ratio is observed [A. Mellnik et al., Nature 511, 449 (2014)]. We consider analytically and by micromagnetic modeling the dependence of this excitation on the frequency and magnitude of the microwave current. The analogies of the vortex dynamics and the Landau phase-transition theory are demonstrated. These findings open the possibility to excite gyrotropic vortex motion with the current densities far lower than by any other means.

• Received 3 March 2015
• Revised 17 August 2015

DOI:https://doi.org/10.1103/PhysRevB.92.094432