Model of Antiferromagnetic Superconductivity

TL;DR

This paper introduces a simple lattice model demonstrating how doping an antiferromagnetic Mott insulator can induce superconductivity through Schafroth pairing, combining magnetic order with superconducting properties.

Contribution

The model shows how doping a Mott insulator with holes can lead to superconductivity via Schafroth pairing while maintaining antiferromagnetic order, a novel theoretical insight.

Findings

Doped holes become mobile charge carriers.

Interactions induce Schafroth pairing at low doping.

The model suggests coexistence of superconductivity and antiferromagnetism.

Abstract

We present a simple model that supports superconductive and antiferromagnetic ordering. The model consists of a system of electrons on a simple cubic lattice that move by tunnel effect and interact via antiferromagnetic Ising spin couplings and short range repulsions: these include infinitely strong Hubbard forces that prevent double occupancy of any lattice site. Hence, under the filling condition of one electron per site and at sufficiently low temperature, the system is an antiferromagnetic Mott insulator. However, when holes are created by suitable doping, they are mobile charge carriers. We show that, at low concentration, their interactions induced by the above interelectronic ones lead to Schafroth pairing. Hence, under certain plausible but unproved assumptions, the model exhibits the off-diagonal long range order that characterises superconductivity, while retaining the antiferromagnetic ordering.