Optimization Of The Skyrmion Racetrack Design By The Modulation Of Magnetocrystalline Anisotropy

Magnetic skyrmions are promising building blocks for next generation data storage due to their stability,small size and extremely low currents to drive them,which can be used instead of traditional magnetic domain walls to store information as data bits.However,skyrmions can drift from the direction of electron flow due to the Magnus force and thus may annihilate at the racetrack edge,resulting in the loss of information.This thesis is based on micromagnetics and used the software OOMMF to simulate the motion of skyrmions in two kinds of optimized racetracks by the modulation of magnetocrystalline anisotropy.The main results are as follows:1.We propose a new skyrmion-based racetrack structure by adding high-K materials(materials with high magnetic crystalline anisotropy)at the edges,which confines the skyrmions in the center region of the metallic racetrack efficiently.According to our micromagnetic simulations,this design can overcome both the clogging and annihilation of skyrmions.Lateral and longitudinal oscillations occur near the boundaries of the racetrack.However,the effect of the DMI value of the edge materials on the velocity of skyrmions is negligible.Moreover,the racetrack design can be optimized by tuning the material and geometric parameters of the racetrack.As a result,the skyrmions can be driven at a high speed in the racetrack under relatively smaller driving currents.2.We proposed another skyrmion-based racetrack with dual channels,which updates and optimizes the representation of binary data in the racetrack.The simulation results show that by varying the values of D,wm,Kuv,it is possible to adjust the motion of skyrmions in a single or dual channel.