Pairing correlation of the Kagome-lattice Hubbard model with the nearest-neighbor interaction

TL;DR

This study investigates the superconducting pairing mechanisms in Kagome lattice materials, revealing how on-site and nearest-neighbor interactions influence the dominant pairing symmetry, which aids in understanding the superconductivity in VSb compounds.

Contribution

It demonstrates how nearest-neighbor interactions can alter the dominant pairing symmetry in the Kagome-Hubbard model, providing insights into the superconductivity of VSb materials.

Findings

On-site Coulomb interaction U favors next-nearest-neighbour d pairing.

Nearest-neighbor V interaction can induce p pairing.

Doping near the Dirac point influences pairing symmetry.

Abstract

A recently discovered family of Kagome lattice materials, $\emph{A}\mathrm{V}_{3}\mathrm{Sb}_{5}$($\emph{A}$= $\mathrm{K,Rb,Cs}$), has attracted great interest, especially in the debate over its dominant superconducting pairing symmetry. To explore this issue, we study the superconducting pairing behavior within the Kagome-Hubbard model through the constrained path Monte Carlo method. It is found that doping around the Dirac point generates a dominant next-nearest-neighbour-$d$ pairing symmetry driven by on-site Coulomb interaction $U$. However, when considering the nearest-neighbor interaction $V$, it may induce nearest-neighbor-$p$ pairing to become the preferred pairing symmetry. Our results provide useful information to identify the dominant superconducting pairing symmetry in $\emph{A}\mathrm{V}_{3}\mathrm{Sb}_{5}$ family.