A photoemission study of the bandstructure of InSb (100)

Abstract

Angle resolved photoemission spectroscopy with synchrotron radiation was used to study the valence band structure of InSb (100). Normal emission energy distribution curves exhibit direct transitions from the valence band maximum Γ8 at the Γ-point of the Brillouin zone and along the [100] direction (Δ). The splitting of the valence band maximum along Δ into a heavy hole band Δ5(hh) and a light hole band Δ5(lh) is clearly resolved. The amount of the splitting is found to be < 200 meV. In addition, we find transitions from the spin-orbit split valence band Γ7. The valence band spin-orbit splitting at the Γ-point is determined to be (750 ± 50) meV. The dispersion behaviour of light and heavy hole bands and the spin-orbit split valence band as well as the resulting data for spin-orbit and light-hole/heavy-hole-band splitting of the topmost valence bands are compared to band structures calculated by nonlocal pseudopotential and self-consistent local-density approximations.