Three-dimensional band mapping by angle-dependent very-low-energy electrondiffraction and photoemission: Methodology and application to Cu - art. no. 205108

A method of band mapping providing full control of the three-dimensional k is described in detail. Angle-dependent very-low-energy electron diffractio n is applied to determine the photoemission final states along a Brillouin zone symmetry line parallel to the surface; photoemission out of these stat es is then utilized to map the valence bands in the constant-final-state mo de. The method naturally incorporates the non-free-electron and excited-sta te self-energy effects in the unoccupied band, resulting in an accuracy sup erior over conventional techniques. Moreover, its intrinsic accuracy is les s limited by lifetime broadening. As a practical advantage, the method prov ides access to a variety of lines in the Brillouin zone using only one crys tal surface. We extensively tested the method on Cu. Several new aspects of the electronic structure of this metal are determined, including; non-free -electron behavior of unoccupied bands and missing pieces of the Valence ba nd.