Simple model of anisotropic pairing with repulsive interactions

TL;DR

This paper introduces a simple tight binding model with multiple orbitals per site that exhibits anisotropic superconductivity driven by repulsive interactions, applicable across all fillings and repulsion strengths.

Contribution

It presents a novel minimal model demonstrating anisotropic pairing induced by repulsive interactions with orbital symmetry considerations.

Findings

Superconductivity occurs at all fillings.

Anisotropic superconducting phase arises from orbital symmetry differences.

Superconductivity persists for all on-site repulsion values.

Abstract

A simple tight binding model with repulsive interactions is studied. The inclusion of more than one orbital per site leads to assisted hopping effects, and, when the orbitals involved have different symmetries, to an anisotropic superconducting phase. Superconductivity exists for all fillings, and for all values of the on site repulsion.