/***************************************************************** Description: This mumax3 script demonstrates a skyrmion racetrack driven by spin-orbit torques implemented using the existing slonczewski spin transfer torque implementation This file is written for the mumax3 workshop organised for the spintronic seminar series in the summer of 2020. For more information go to https://www.mumax.ugent.be/mumax3-workshop Authors: Dr. Jonathan Leliaert (jonathan.leliaert@ugent.be) Dr. Jeroen Mulkers (jeroen.mulkers@ugent.be) ******************************************************************/ // Skyrmion racetrack setgridsize(256,64,1) setcellsize(1e-9,1e-9,1e-9) setpbc(4,0,0) Msat = 580e3 Aex = 15e-12 Dind = 3.0e-3 Ku1 = 0.8e6 AnisU = vector(0,0,1) alpha = 0.1 m = neelskyrmion(-1, 1).transl(-40e-9,0,0) minimize() //Add SOT //define constants and set slonczewksi parameters SOTxi := -2 AlphaH := 0.15 Pol = alphaH Lambda = 1 Epsilonprime = alphaH*SOTxi/2 Fixedlayer = vector(0,-1,0) //p //define current J = vector(0,0,abs(-2e11)) //in z-direction autosave(m,1e-10) tableAutosave(1e-11) tableAdd(ext_bubblepos) run(2.5e-9)