Wiggling skyrmion propagation under parametric pumping

Magnetic skyrmion motion under parametric pumping is numerically investigated. Parametric pumping with a perpendicularly oscillating electric field can excite the breathing modes of a skyrmion because an electric field can modify the magnetic anisotropy. Interestingly, using an in-plane static magnetic field to break the rotational symmetry, a perpendicularly oscillating electric field can drive a skyrmion undergoing a wiggling motion along a well-defined trajectory. The skyrmion velocity can reach several meters per second when the frequency of the electric field is close to the frequency of the skyrmion breathing motion. The physics is revealed in a generalized Thiele equation where a net spin current excited by the parametric pumping can drive the skyrmion propagation through angular momentum transfer. Our results open new possibilities for manipulating skyrmions in both metals and insulators with low-power consumption. Moreover, the oscillating skyrmion can act as a microwave generator for future spintronic applications such as a nanotool on a diamond nitrogen-vacancy center.