Polarization-dependent angle-resolved photoemission study of a surface state on GaSb(110)

Using polarization-dependent, angle-resolved photoemission, a prominent nondispersive structure in the normal emission spectra from GaSb(110) has been identified as being due to transitions from the Sb-derived dangling-bond surface state. The atomic-orbital character of the surface state was confirmed to be mainly pz-like, and the dispersion of the surface state along the {Γ}{} X{} direction in the surface Brillouin zone was observed. Using symmetry selection rules, an accurate determination of Γ₈ᵛ, the valence-band maximum (VBM), was made. The surface state was found to be 150±{}100 meV above the VBM, showing that the surface state is indeed an intrinsic intergap surface state.