An individual Mn acceptor in GaAs is mapped by Cross-sectional Scanning
Tunneling Microscopy (X-STM) at room temperature and a strongly anisotropic
shape of the acceptor state is observed. An acceptor state manifests itself as
a cross-like feature which we attribute to a valence hole weakly bound to the
Mn ion forming the (Mn2+3d5+hole) complex. We propose that the observed
anisotropy of the Mn acceptor wave-function is due to the d-wave present in the
acceptor ground state.Comment: Proceedings of the SIMD-4 conference. Hawaii, USA (December 1-5,
2003