Photoelectron diffraction effect in the highly ordered Si(5 5 7)/Pb surface

The electronic structure of vicinal Si(5 5 7) surface covered with 2 ML Pb, ordered after annealing at 640 K as found previously [C. Tegenkamp, Z. Kallassy, H.-L. Gunter, V. Zielasek, H. Pfnür, Eur. Phys. J. B 43 (2005) 557; C. Tegenkamp, Z. Kallassy, H. Pfnür, H.-L. Gunter, V. Zielasek, M. Henzler, Phys. Rev. Lett. 95 (2005) 176804], is studied with angle-resolved photoemission spectroscopy (ARPES) at a temperature of 130 K. The spectra show a superposition of Pb-induced electronic surface states and the Si(1 1 1) bulk band states. The observed splitting of a Si bulk band suggests photoelectron diffraction on the one-dimensional grid of the vicinal surface.