Surface band structure of MBE-grown GaAs(001)-2 × 4

Angle-resolved photoemission measurements using synchrotron radiation have been performed for the As-stable GaAs(001)-2 × 4 reconstruction, which was grown in situ by molecular beam epitaxy. Measurements made at high symmetry points and along symmetry lines of the surface Brillouin zones show weakly dispersing dangling bond-like surface states in the energy range between -1.6 eV and the top of the valence band and a nearly dispersionless state near -3 eV.