Controlled Domain-Wall Pair to Skyrmion Conversion in Typical Junction Geometry Useful for Magnetic Memory Devices

Abstract

One of the important goals of modern spintronics research is to develop energy efficient magnetic memory devices. It has been recently proposed that race track memory based on skyrmion can be used as energy efficient magnetic memory due to the small threshold current required for setting its motion. Here, using micromagnetic simulation, we studied the mechanism of skyrmion creation from a pair of domain walls in a magnetic nano track geometry composed of two narrow channels and a wide channel. Interestingly, by using optimum material parameters, fixed current density, and separation between the narrow channels, we obtained velocity up to ∼450 m s−1 during the skyrmion dynamics. The selected material parameters and geometry allow the stabilization as well as controlled manipulation of topological magnetic texture. Based on these results we propose that the skyrmion based race-track memory with more than one narrow channel in a junction geometry with suitable magnetic parameters relevant for spintronic devices will enable better control of skyrmion dynamics.