Layer-thickness dependence in tunneling magnetoresistance and current-driven magnetization reversal using GaMnAs-based double-barrier structures

We have investigated the layer-thickness dependence on tunneling magnetoresistance (TMR) in double-barrier structures using GaMnAs-based magnetic tunneling junctions in order to clarify the origin of low threshold current density for current-driven magnetization orientation reversal. The TMR characteristics are well explained by assuming the spin configurations due to the difference in coercive force in each magnetic layer. Using the thin middle magnetic layer, current-driven magnetization reversal in low current density and spin accumulation are realized.