Extraction of the electron self-energy from angle-resolved photoemission data: Application toBi2Sr2CaCu2O8+x

Abstract

The self-energy $\ensuremath{\Sigma}(\mathbf{k},\ensuremath{\omega}),$ the fundamental function that 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 ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+x}$ in the normal, superconducting, and pseudogap phases.