Exact Electron-Pairing Ground States of Tight-Binding Models with Local Attractive Interactions

TL;DR

This paper introduces a class of exactly solvable tight-binding models with local attractive interactions, demonstrating electron-pair condensation at specific fillings across any dimension.

Contribution

It provides exact solutions for ground states with electron pairs in models with local attraction, extending understanding of pairing mechanisms in correlated electron systems.

Findings

Exact ground states with electron pairs identified

Models exhibit electron-pair condensation at specific fillings

Applicable in any spatial dimension

Abstract

We present a class of exactly solvable models of correlated electrons. The models are defined in any dimension $d$ and consist of electron-hopping terms and local attractive interactions between electrons. For each even number of electrons less than or equal to $1/(d+1)$-filling, we find the exact ground state in which all electrons form pairs of a certain type, and thus the models exhibit an electron-pair condensation.