| Autor: |
Riva G; Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, UPS, CNRS, and European Theoretical Spectroscopy Facility (ETSF), 118 route de Narbonne, F-31062 Toulouse, France., Romaniello P; Laboratoire de Physique Théorique, CNRS, Université de Toulouse, UPS, and European Theoretical Spectroscopy Facility (ETSF), 118 route de Narbonne, F-31062 Toulouse, France., Berger JA; Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, UPS, CNRS, and European Theoretical Spectroscopy Facility (ETSF), 118 route de Narbonne, F-31062 Toulouse, France. |
| Abstrakt: |
We present the multichannel Dyson equation that combines two or more many-body Green's functions to describe the electronic structure of materials. In this work we use it to model photoemission spectra by coupling the one-body Green's function with the three-body Green's function. We demonstrate that, unlike methods using only the one-body Green's function, our approach puts the description of quasiparticles and satellites on an equal footing. We propose a multichannel self-energy that is static and only contains the bare Coulomb interaction, making frequency convolutions and self-consistency unnecessary. Despite its simplicity, we demonstrate with a diagrammatic analysis that the physics it describes is extremely rich. Finally, we present a framework based on an effective Hamiltonian that can be solved for any many-body system using standard numerical tools. We illustrate our approach by applying it to the Hubbard dimer and show that it is exact both at 1/4 and 1/2 filling. |
