Ferromagnetic Pairing States on Two-Coupled Chains

TL;DR

This paper introduces a model with two coupled chains that simultaneously exhibits ferromagnetism and electron-pair condensation, with rigorous proof of fully polarized ferromagnetic pairing ground states.

Contribution

It presents a new concrete model on two chains demonstrating simultaneous ferromagnetism and electron pairing, including a rigorous proof of its ground states.

Findings

Model exhibits ferromagnetic and pairing ground states.

Ground states are fully polarized ferromagnetic pairings.

Higher dimensional extension of the model is also discussed.

Abstract

We propose a concrete model which exhibits ferromagnetism and electron-pair condensation simultaneously. The model is defined on two chains and consists of the electron hopping term, the on-site Coulomb repulsion, and a ferromagnetic interaction which describes ferromagnetic coupling between two electrons, one on a bond in a chain and the other on a site in the other chain. It is rigorously shown that the model has fullypolarized ferromagnetic pairing ground states. The higher dimensional version of the model is also presented.