Ground-State Instabilities in The One-dimensional Penson-Kolb-Hubbard Model

TL;DR

This paper investigates various electronic instabilities in the one-dimensional Penson-Kolb-Hubbard model using an approximate Bethe-Salpeter approach, revealing phase diagrams and stability conditions across different densities and parameters.

Contribution

It provides a comprehensive analysis of ground-state instabilities in the 1D Penson-Kolb-Hubbard model at arbitrary densities and parameters, extending understanding of phase behavior.

Findings

No transition at half filling without on-site interaction for negative pair-hopping.

The model behaves similarly to the Hubbard model when |W/t|<π/sin(k_F).

Phase diagrams are mapped for various densities and parameters.

Abstract

Different kinds of instabilities (CDW, SDW, SS) in the 1D Hubbard model with pair-hopping interaction are investigated using an approximate Bethe-Salpeter equation. The study is performed at any density of electrons and for arbitrary values of the model parameters. In the absence of the on-site interaction, no transition occurs at half filling for any finite negative pair-hopping parameter, in agreement with recent results; our calculation suggests that the Penson-Kolb model (t,W) with $\mid W/t\mid<\pi/\sin k^{}_F$ behaves qualitatively like the Hubbard model (t,U). Phase diagrams of the Penson-Kolb-Hubbard model (t,U,W) at various densities are presented.