Enhancement of pair correlation in a one-dimensional hybridization model

TL;DR

This paper introduces an integrable 1D electron model with local orbitals that enhances pair correlations in the ground state, revealing different effects under attractive and repulsive interactions.

Contribution

It presents a novel integrable 1D hybridization model that incorporates local orbitals and analyzes their impact on electron pairing and effective mass.

Findings

Local orbitals increase pair correlation in the ground state for attractive interactions.

Effective mass of Cooper-pair-like singlets is enhanced by local orbitals.

Persistent current is reduced when interactions are attractive.

Abstract

We propose an integrable model of one-dimensional (1D) interacting electrons coupled with the local orbitals arrayed periodically in the chain. Since the local orbitals are introduced in a way that double occupation is forbidden, the model keeps the main feature of the periodic Anderson model with an interacting host. For the attractive interaction, it is found that the local orbitals enhance the effective mass of the Cooper-pair-like singlets and also the pair correlation in the ground state. However, the persistent current is depressed in this case. For the repulsive interaction case, the Hamiltonian is non-Hermitian but allows Cooper pair solutions with small momenta, which are induced by the hybridization between the extended state and the local orbitals.