Single and double electron emission: combination of projection operator and nonequilibrium Green's function approaches

Abstract

This work provides a unified theoretical treatment of the single and correlated double-electron emission from a general electronic system. Using Feshbach projection method, the states of interest are selected by the projection operator; the Feshbach-Schur map determines the effective Hamiltonian and the optical potential for the emitted electrons. On the other hand, the nonequilibrium Green's functions method is demonstrated to be a complementary approach and an explicit correspondence between both methods is established. For a self-contained exposition some results on single electron emission are re-derived using both formalisms. New insights and results are obtained for the correlated electron-pair emission: This includes the effective two-electron Hamiltonian, the explicit form of the Feshbach self-energy in terms of the many-body self-energies, and the diagrammatic expansion of the two-particle current. As an illustration of the diagrammatic technique the process of the two-particle emission assisted by the excitation of plasmons is explicitly worked out.

8 figures

References in corpus (4)

• Exponential localization of Wannier functions in insulators
• Transport in molecular states language: Generalized quantum master equation approach
• Diagrammatic expansion for positive spectral functions beyond GW: Application to vertex corrections in the electron gas
• Diagrammatic expansion for positive density-response spectra: Application to the electron gas

Cited by in corpus (2)

• Dynamically screened vertex correction to $GW$
• Noise Correlations in time- and angular-resolved photoemission spectroscopy