Electronic structure of the neutral manganese acceptor in gallium arsenide

A new manganese-related isotropic electron-spin-resonance signal at g=2.77 has been observed in GaAs. It is shown to arise from the neutral Mn acceptor, MnE0. The analysis gives an answer to the longstanding question of whether the structure of MnE0 corresponds to 3dE4 or do 3dE5+hole. The data clearly favor the latter case, thus revealing that Mn is an exception within the 3d acceptor family in GaAs. (IAF)