Extraction of the electron self-energy from angle-resolved photoemission data: Application to Bi2Sr2CaCu2O8+x

The self-energy Sigma(k, 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 Bi2Sr2CaCu2O8+x in the normal, superconducting, and pseudogap phases. [S0163-1829(99)13433-7].