  We present results on the direct spatial mapping of the wave-function of a
hole bound to a Mn acceptor in GaAs. To investigate individual Mn dopants at
the atomic scale in both ionized and neutral configurations, we used a room
temperature cross-sectional scanning tunneling microscope (X-STM). We found
that in the neutral configuration manganese manifests itself as an anisotropic
cross-like feature. We attribute this feature to a hole weakly bound to the Mn
ion forming the [Mn2+(3d5) + hole] complex.
