Antiferromagnetism and chiral-d wave superconductivity in a honeycomb lattice close to Mott state

TL;DR

This paper investigates the coexistence and interplay of antiferromagnetism and chiral-d wave superconductivity in a honeycomb lattice near a Mott insulator state, revealing enhanced superconductivity and unexpected nodal dispersion relations.

Contribution

It introduces a study of AFM and chiral-d wave SC in a honeycomb lattice using a t-J model, highlighting the enhancement of SC by AFM and the emergence of nodal dispersion relations.

Findings

AFM enhances chiral-d wave superconductivity

Nodal dispersion relations appear at specific band fillings

Comparison with extended-s wave states highlights unique features

Abstract

The antiferromagnetism (AFM) and chiral-d wave superconductivity (SC) in a honeycomb lattice close to an antiferromagnetic (AF) Mott state at half band filling are studied with a t-J model and slave boson mean field theory. The order parameters and single particle dispersion relations at different band filling fractions are investigated. It is found that the AFM enhances the SC, and leads to nodal single particle dispersion relations at two band filling fractions. These unexpected nodal dispersion relations out of nodeless chiral-d wave superconducting order are discussed. A comparison between AF chiral-d wave states and AF extended-s wave states is also given to highlight the pertinent features in chiral-d wave superconducting states. This study may be related to the honeycomb lattice materials such as the In$_3$Cu$_2$VO$_9$ compound.