Effective t-J model of pairing: singlet versus triplet

TL;DR

This paper reviews the effective t-J model's role in understanding singlet and triplet pairing mechanisms, emphasizing the influence of kinetic exchange interactions in strongly correlated systems, including a case study of triplet pairing on a 2D lattice.

Contribution

It provides a comparative analysis of singlet and triplet pairing within the t-J model and discusses the effects of ferromagnetic and antiferromagnetic exchange interactions in orbitally degenerate systems.

Findings

Kinetic exchange interactions induce both singlet and triplet pairing.

Antiferromagnetic exchange favors singlet pairing, while ferromagnetic exchange can promote triplet pairing.

A concrete example of triplet pairing on a two-dimensional lattice is presented.

Abstract

The t-J model is regarded as a canonical model of spin-singlet pairing induced by the {\em kinetic exchange interaction} responsible also for an antiferromagnetic ordering in the strongly correlated narrow-band systems. In the orbitally degenerate systems both ferromagnetic and antiferromagnetic kinetic exchange interactions occur. I review briefly the analogy between the singlet and triplet types of pairing, as well as draw some general conclusions about the pairing induced by these exchange interactions. The general discussion is also illustrated with a concrete case of a two-dimensional lattice with the spin triplet pairing.