Energy bands of (111) copper thin films

Abstract

A tight-binding calculation of the energy bands of a 30-layer (111) copper thin film is performed using the same set of 34 Hamiltonian matrix element parameters that we used in our (100) and (110) thin-film calculations. The bands are calculated at 61 points in the irreducible (1/12) two-dimensional Brillouin zone (2D BZ) both with and without a surface parameter shift. The planar and total densities of states are presented. We find a free-electron-like surface state which lies well above the Fermi energy independent of the surface parameter shift. Gartland and Slagsvold have inferred from their photoelectric data that this (or perhaps another surface state in the same region of the 2D BZ) lies below $E_F$. We present an argument which indicates that their interpretation of their data may be incorrect.