Extraction of the Electron Self-Energy from Angle Resolved Photoemission Data: Application to Bi2212

Abstract

The self-energy $Σ({\bf k},ω)$, the fundamental function which describes the effects of many-body interactions on an electron in a solid, is usually difficult to obtain directly from experimental data. In this paper, we show that by making certain reasonable assumptions, the self-energy can be directly determined from angle resolved photoemission data. We demonstrate this method on data for the high temperature superconductor $Bi_2Sr_2CaCu_2O_{8+x}$ (Bi2212) in the normal, superconducting, and pseudogap phases.

expanded version (6 pages), to be published, Phys Rev B (1 Sept 99)