Effects of a k-dependent Hybridization on the Fermi Surface of an Extended $d-p$ Hubbard Model

TL;DR

This study explores how k-dependent hybridization influences the Fermi surface topology in an extended d-p Hubbard model, revealing its significant role in Lifshitz transitions and pseudogap suppression, aligning with experimental observations in cuprates.

Contribution

It provides a systematic analysis of the impact of d-p hybridization on Fermi surface topology, pseudogap behavior, and Lifshitz transition in the Hubbard model, highlighting hybridization as a control parameter.

Findings

Hybridization affects the Lifshitz transition from hole-like to electron-like Fermi surface.

Hybridization and doping both suppress the pseudogap in the low doping regime.

Results qualitatively agree with experimental data on cuprate Nd-LSCO.

Abstract

The topology of the Fermi surface of an extended $d-p$ Hubbard model is investigated using the Green's function technique in a n-pole approximation. The effects of the $d-p$ hybridization on the Fermi surface are the main focus in the present work. Nevertheless, the effects of doping, Coulomb interaction and hopping to second-nearest-neighbors on the Fermi surface, are also studied. Particularly, it is shown that the crossover from hole-like to electron-like Fermi surface (Lifshitz transition) is deeply affected by the $d-p$ hybridization. Moreover, the pseudogap present in the low doping regime is also affected by the hybridization. The results show that both the doping and the hybridization act in the sense of suppresses the pseudogap. Therefore, the systematic investigation of the Fermi surface topology, shows that not only the doping but also the hybridization can be considered as a control parameter for both the pseudogap and the Lifshitz transition. Assuming that the hybridization is sensitive to external pressure, the present results agree qualitatively with recent experimental data for the cuprate Nd-LSCO.