Triplet p-wave superconductivity in low-density extended Hubbard model with Coulomb repulsion

TL;DR

This paper investigates p-wave superconductivity in low-density extended Hubbard models with Coulomb repulsion, showing that strong coupling favors p-wave pairing even with intersite interactions.

Contribution

It demonstrates that in the strong-coupling limit, the main superconducting instability is p-wave pairing, consistent with models neglecting intersite Coulomb interactions.

Findings

P-wave pairing dominates in the low-density extended Hubbard model.

Intersite Coulomb repulsion V does not alter the leading-order p-wave instability.

Results are applicable to 3D and 2D lattices in the strong-coupling regime.

Abstract

We analyze superconducting instabilities in 3D and 2D extended Hubbard model with Coulomb repulsion between electrons on neighboring sites in the limit of low electron density ($n_{el} \rightarrow 0$) on simple cubic (square) lattice. We show that in a realistic strong-coupling case $U\gg V\gg W$ ($U$ and $V$ are the onsite and the intersite Coulomb repulsions, $W$ the bandwidth) the main SC instability corresponds to the p-wave pairing and in the leading order is correctly described by the equations obtained earlier in the absence of the intersite Coulomb interaction V=0.