Phase Diagram and Superconducting Properties of an Exactly Solvable Model with Correlated Hopping

TL;DR

This paper presents an exact solution of a one-dimensional strongly correlated electron model with correlated hopping and hole interactions, revealing a complex phase diagram with metallic, superconducting, insulating, and phase-separated phases.

Contribution

It provides an exact analysis of the phase diagram and physical properties of a novel correlated electron model with correlated hopping and hole interactions.

Findings

Existence of gapless metallic and superconducting phases

Presence of insulating and phase-separated regions

Exact calculations of conductivity stiffness, effective mass, and compressibility

Abstract

The model of strongly correlated electrons with the correlated hopping term and an additional interaction between holes $V$ is solved exactly in one dimension at a special point where the number of hole pairs is conserved. As a function of the interaction $V$ the phase diagram has a rich structure. There exist gapless phases with dominating density-density correlations (metallic) or pair-pair correlations (superconducting) as well insulating and phase-separated phases. The stiffness constant of the conductivity, the effective transport mass, and the compressibility are also exactly calculated in several regions of the phase diagram.