Distortion of an Unoccupied Band in Be by the Electron-Plasmon Interaction

Abstract

By means of angle-resolved photoemission, the unoccupied band structure of Be along the $\Delta$ axis has been determined. While the data are in generally good agreement with the results of a self-consistent pseudopotential calculation, additional structure near the threshold for plasmon production is seen. It is argued that this structure is a many-body distortion caused by the electron-plasmon interaction.