$\eta$-pairing in a two-band model of spinless fermions

TL;DR

This paper investigates a two-band model of spinless fermions with hybridization, revealing a mechanism for $ ext{eta}$-pairing that could explain high-temperature superconductivity in hydrogen-rich materials.

Contribution

It introduces a novel pairing mechanism via two-particle hybridization leading to $ ext{eta}$-pairing and potential $p$-superconducting states in a two-band spinless fermion model.

Findings

Exact Bethe ansatz solution in 1D confirms hybridization reduces repulsion.

Strong interaction induces attractive effective interaction, enabling $ ext{eta}$-pairing.

Proposed mechanism may explain high-temperature superconductivity in hydrogen-rich materials.

Abstract

We study the two-band model of spinless fermions in which itinerant fermions interact with localized fermions through the two-particle hybridization. In 1D version, the model has exact solution using the Bethe ansatz. It has been shown that accounting for two-particle hybridization reduces the repulsive interaction between itinerant fermions. In the case of strong interaction, the effective interaction between itinerant fermions is attractive, and $\eta$-pairing of spinless fermions is realized. The proposed pairing mechanism via two-particle hybridization can lead to $p$-superconducting states with $\eta$-pairing. $\eta$-pairing of spinless fermions could explain the phenomenon of high-temperature superconductivity experimentally observed in hydrogen-rich materials at high pressures.