Analysis of anisotropic tunnel magneto-resistance of (Ga,Mn)As/AlAs/(Ga,Mn)As magnetic tunnel junction

Anisotropic tunnel magneto-resistance (TMR) of (Ga,Mn)As/AlAs/(Ga,Mn)As magnetic tunnel junctions (MTJs) was investigated by both experimentation and simulation. The TMR ratios measured at View the MathML source for the fabricated MTJs with magnetic fields applied in the View the MathML source plane along the View the MathML source, and View the MathML source directions were 39%, 19%, and 10%. These asymmetrical TMR ratios can be explained by the magnetic anisotropy of (Ga,Mn)As, in which the cubic magnetic anisotropy dominated the magnetization switching with its easy axis along the View the MathML source directions, whereas the uniaxial anisotropy contributed slightly with its easy axis along the View the MathML source direction. Two models of magnetization reversal were considered: (1) the coherent rotation model and (2) the domain-wall displacement model, for the analysis. As a result, the domain-wall displacement model accurately explained both the TMR ratio and switching field of the fabricated MTJ with View the MathML source junction size.