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arXiv:2004.09562

Fermi-liquid behaviors in three-dimensional polaron system with tunable dispersion

Chen-Huan Wu

Published Apr 20, 2020• 0 citations
arXivHTMLPDF

Abstract

We investigate the electronic properties and electron correlations in a three-dimensional (3D) polaron system with tunable dispersion parameter in Fermi-liquid picture. The polaronic coupling is considered as a weakly attractive bare coupling. Both the single and many-polaron, zero and finite-temperature cases are considered in this paper. The physical quantities, including the self-energy, spectral function, optical conductivity (both the planar and 3D one), free energy, and momentum distribution function, are studied and are been verified exhibit Fermi-liquid features. Both the analytic derivation and numerical calculation are done in this paper to make our results reliable.

DOI
10.48550/arxiv.2004.09562

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Abstract We investigate the electronic properties and electron correlations of the bipolaron formed with the participation of electron-hole excitations in the presence of Yukawa-type coupling (between nonrelativistic fermions) in three spatial dimension. The electron-hole excitation, which is necessary to the formation of bipolaron, leads to imaginary particle-hole channel order parameter, and provide finite boson field mass to the single-polaron dispersion in a broken-symmetry phase. We found that the bipolaron exhibits fermi-liquid features as long as the long-range strong interaction is suppressed, and it behave differently compared to the single-polaron. The bosonic momentum determines the mass of boson field propagator and the gap function, and it also related to the self-energies and the single-particle Green’s functions. The Thouless criterion is also used during the calculation of gap equation at critical temperature (which becomes lower in weak-coupling regime), which corresponds to the pole (instability) of the pair propagator in zero center-of-mass freamwork. The mean field term and the bosonic fluctuation-induced contribution to free energy in Aslamazov-Larkin-type bipolaron diagram are also studied.
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