Surface states on random substitutional alloys

We present first principles KKRCPA calculations of the angle-resolved photoemission spectra from CuNi single crystal surfaces. Two surface states have been identified; a Shockley-type state on the (111) surface, and a Tamm-type state on the (100) surface. We determine their dispersion, and investigate their sensitivity to the form of the surface potential. The disorder broadening and the influence of surface segregation are discussed quantitatively.