New detailed angle-resolved photoemission data are presented, revealing the existence of an Mn-induced state that extends into the band gap of GaAs. In sharp contrast to recent reports we observe that the state is highly dispersive. Spin resolved pho
toemission shows that the band is spin polarized even at room temperature. The results are not consistent with any of the currently discussed band models for ferromagnetism.
Resonant in situ photoemission from Mn 3d states in Ga_{1-x}Mn_{x}As is reported for Mn concentrations down to very dilute limit of 0.1 at %. The properties of the peak at the valence-band maximum reveal an effective interaction between Mn 3d states
for concentration as low as 2.5 %. Concentration-dependent spectral features are analyzed on the basis of first-principles calculations for systems with selected impurity positions as well as for random alloys.
