Anisotropic magnetotransport due to uniaxial magnetic anisotropy in (Ga,Mn)As wires

The in-plane anisotropic magnetotransport feature of 2-μm-wide (Ga,Mn)As wires is examined at 4 K. The magnetoresistance (MR) features as a function of applied field orientation show clear anisotropy associated with the cubic magnetocrystalline anisotropy. Moreover, the field orientation dependence of the magnetization switching field shows two asymmetric peaks along [110] and [1~10], indicating the presence of uniaxial anisotropy along [110]. A simple model incorporating the cubic and uniaxial anisotropies well explains these asymmetric peaks based on magnetization reversal processes via 90° domain wall displacement.