Photoemission spectral functions from the three-body Green's function
Gabriele Riva, Timothée Audinet, Matthieu Vladaj, Pina Romaniello, J. Arjan Berger
SciPost Phys. 12, 093 (2022) · published 15 March 2022
- doi: 10.21468/SciPostPhys.12.3.093
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Abstract
We present an original strategy for the calculation of direct and inverse photo-emission spectra from first principles. The main goal is to go beyond the standard Green's function approaches, such as the $GW$ method, in order to find a good description not only of the quasiparticles but also of the satellite structures, which are of particular importance in strongly correlated materials. To this end we use as a key quantity the three-body Green's function, or, more precisely, its hole-hole-electron and electron-electron-hole parts, and we show how the one-body Green's function, and hence the corresponding spectral function, can be retrieved from it. We show that, contrary to the one-body Green's function, information about satellites is already present in the non-interacting three-body Green's function. Therefore, simple approximations to the three-body self-energy, which is defined by the Dyson equation for the three-body Green's function and which contains many-body effects, can still yield accurate spectral functions. In particular, the self-energy can be chosen to be static which could simplify a self-consistent solution of the Dyson equation. We give a proof of principle of our strategy by applying it to the Hubbard dimer, for which the exact self-energy is available.
Cited by 10
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 2 Gabriele Riva,
- 1 Timothée Audinet,
- 1 Matthieu Vladaj,
- 1 2 Pina Romaniello,
- 1 2 Arjan Berger
- 1 Université de Toulouse / University of Toulouse
- 2 European Theoretical Spectroscopy Facility [ETSF]