All-optical 90-degree switching of magnetization in a ferromagnetic Ga0.98Mn0.02As microbar

All-optical, 90 degrees switching of magnetization has been carried out successfully in a laterally magnetized (Ga,Mn) As microbar with a scanning laser magneto-optical microscope. No external magnetic field was applied during switching. Light was used primarily as local excitation source to elevate the lattice temperature (>T-C/2) at which cubic and uniaxial anisotropies become near equal. Lithography-induced magnetic anisotropy plays a key role in that it breaks the degeneracy of fourfold cubic anisotropy of (Ga,Mn) As to a considerable extent. (C) 2010 American Institute of Physics. [doi:10.1063/1.3352887]