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Article Dans Une Revue Physical Review Letters Année : 2023

The multi-channel Dyson equation: coupling many-body Green's functions

Gabriele Riva
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Arjan Berger

Résumé

We present the multi-channel 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 multi-channel 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.

Dates et versions

hal-04279783 , version 1 (10-11-2023)

Identifiants

Citer

Gabriele Riva, Pina Romaniello, Arjan Berger. The multi-channel Dyson equation: coupling many-body Green's functions. Physical Review Letters, 2023, 131 (21), pp.216401. ⟨10.1103/PhysRevLett.131.216401⟩. ⟨hal-04279783⟩
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