Control of magnetic anisotropy and magnetotransport in epitaxial micropatterned (Ga,Mn)As wire structures

The authors present magnetoresistance characteristics of patterned (Ga,Mn)As wire structures, which depend on wire width and thus overall magnetic anisotropy. Cubic and uniaxial magnetocrystalline anisotropies seem to be the dominant magnetic contributions in 2-μm-wide wires, whereas both magnetocrystalline and shape-induced anisotropies contribute to magnetization reversal in 1-μm-wide wires, as manifested by jumps in the magnetoresistance curves. The role of these two anisotropies in the magnetization reversal is discussed, together with the determination of magnetic easy/hard axes of (Ga,Mn)As wires.