7 - Dynamics of magnetic skyrmions

Abstract

This chapter deals with the skyrmion dynamics excited by spin-polarized electrical current in different magnetic systems, such as ferromagnets, metallic multilayers as well as synthetic antiferromagnets. We will describe the different origin of a spin-polarized current, which can exert a spin-transfer torque onto the magnetization texture of a skyrmion. We will show that an in-plane polarized current promotes shifting dynamics, which is characterized by an in-plane deflection angle, i.e., the skyrmion Hall angle, and is at the basis of racetrack memory. On the other hand, an out-of-plane polarized current excites oscillatory magnetization dynamics, such as breathing mode, which can be used to build spin-torque nano oscillators and detectors. We will point out the characteristics of the skyrmion dynamics by underlining the benefits and drawbacks from an application viewpoint, and, eventually, we will provide an outlook on the next experimental evidences to be achieved to push skyrmions toward a real-device implementation.