THE POLARIZATION DEPENDENCE OF BI-INDUCED SURFACE-STATES ON GAAS(110)

We report on a study of the Bi-induced surface states of the GaAs(110)-Bi(1 x 1) monolayer system using angle-resolved photoelectron spectroscopy with a synchrotron radiation source. The overlayer system possesses at least three detectable surface states with two-dimensional character. We have determined their band dispersion along the high symmetry directions of the GaAs(110) surface Brillouin zone, and their polarization dependence. In this paper we demonstrate that all three Bi-induced states are predominantly p(z) like, although the state with the highest binding energy appears to posses slightly more p(xy) character than the other two. In contrast, previous photoemission studies of the GaAs(110)-Sb(1 x 1) monolayer system have demonstrated that the corresponding high binding energy state has predominantly p(xy) character.