ANGLE-RESOLVED PHOTOEMISSION FROM CU(001) - INFLUENCE OF ANGULAR RESOLUTION ON LINE-WIDTHS

In a recent study of angle-resolved photoemission from Cu(001) Aebi et al. [Solid State Commun. 88, 19 (1993)] investigated the influence of highest angular resolution on the experimental linewidths. They obser ve an unexplained dramatic narrowing of an s,p-band direct transition line, with the final electron state located in the second surface Bril louin Zone (SBZ). In contrast, almost no such narrowing is observed wh en the final state is located in the first SBZ, although the photohole initial state band is the same. We have performed calculations, which consistently explain all observations of Aebi et al. in terms of the bulk band structure, without the need to invoke additional broadening mechanisms as proposed by the authors.