WestudythequantumsizeeffectsofanMgO-baseddoublebarriermagnetictunneljunctionwitha nonmagnetic-metal (DBMTJ-NM)(semiconductor(DBMTJ-SC))spaceronthechargecurrentandthe spin-transfer torque(STT)componentsusingnon-equilibriumGreen'sfunction(NEGF)formalism.The results showoscillatorybehaviorduetotheresonanttunnelingeffectdependingonthestructure parameters.We find thatthechargecurrentandtheSTTcomponentsintheDBMTJ-SCdemonstratethe magnitude enhancementincomparisonwiththeDBMTJ-NM.ThebiasdependenceoftheSTTcompo- nents inaDBMTJ-NMshowsdifferentbehaviorincomparisonwithspinvalvesandconventionalMTJs. Therefore,bychoosingaspecific SCspacerwithsuitablethicknessinaDBMTJthechargecurrentandthe STT componentssignificantly increasesothatonecandesignadevicewithhighSTTandfastermag- netization switching.
