Quasiparticle Many-Body Dynamics of Highly Correlated Electronic Systems

TL;DR

This paper introduces a self-consistent Green's function approach for analyzing quasiparticle dynamics in highly correlated electronic systems, effectively capturing strong interactions and damping effects across various models.

Contribution

It presents a novel Irreducible Green's Functions method for quasiparticle spectrum calculation applicable to multiple models, including Hubbard and Anderson models.

Findings

Derived an interpolative quasiparticle spectrum valid in atomic and band limits.

Calculated quasiparticle damping self-consistently for strongly correlated systems.

Applied the method to various models, demonstrating its versatility.

Abstract

The self-consistent theory of the correlation effects in Highly Correlated Systems(HCS) is presented. The novel Irreducible Green's Functions(IGF) method is discused in detail for the Hubbard model and random Hubbard model. The interpolative solution for the quasiparticle spectrum, which is valid for both the atomic and band limit is obtained. The (IGF) method permits to calculate the quasiparticle spectra of many-particle systems with the complicated spectra and strong interaction in a very natural and compact way. The inelastic scattering corrections leads to the damping of the quasiparticles and are the main topic of the present consideration. The calculation of the damping has been done in a self-consistent way for both limits. For the random Hubbard model the weak coupling case has been considered and the self-energy operator has been calculated using the combination of the IGF method and Coherent Potential Approximation (CPA). The other applications of the method to s-f model, Anderson model, Heisenberg antiferromagnet, electron-phonon interaction models are discussed briefly.