Ensemble Green's function theory for interacting electrons with degenerate ground states
Research output: Contribution to journal › Article
An ensemble Green's function formalism, based on the von Neumann density matrix approach, to calculate one-electron excitation spectra of a many-electron system with degenerate ground states is proposed. A set of iterative equations for the ensemble Green's function and self-energy is derived and a simplest approximation corresponding to an ensemble GW approximation is naturally obtained. The derivation is based on the Schwinger functional derivative technique and does not assume any adiabatic connection between a noninteracting and an interacting ground state.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Journal||Physical Review B|
|Publication status||Published - 2019|