Influence of strain on the tunneling magnetoresistance in diluted magnetic semiconductor trilayer and double barrier structures

The influence of strain on hole tunneling in trilayer and double barrier structures made of two diluted magnetic semiconductors (DMS) (Ga, Mn)As, separated by a thin layer of non-magnetic AlAs is investigated theoretically. The strain is caused by lattice mismatch as the whole structure is grown on a (In0.15Ga0.85)As buffer layer. The tensile strain makes the easy axis of magnetization orient along the growth direction. We found that biaxial strain has a strong influence on the tunneling current because the spin splitting at k=0 is comparable to the Fermi energy EFEF. Tensile strain decreases the tunneling magnetoresistance ratio.