Chiral finite-momentum superconductivity in the tetralayer graphene

TL;DR

This paper investigates the pairing mechanism in rhombohedral tetralayer graphene, revealing dominant chiral p-wave superconductivity at low densities and characterizing different superconducting phases.

Contribution

It introduces a density-density interaction model within RPA that explains experimental superconductivity and predicts distinct chiral finite-momentum phases.

Findings

Chiral p-wave pairing dominates at low densities.

Superconducting regions SC1 and SC2 exhibit finite-momentum pairing.

SC4 shows zero-momentum spin-singlet superconductivity.

Abstract

Motivated by the recent experimental discovery of superconductivity in rhombohedral tetralayer graphene, we investigate the pairing mechanism arising from the density-density interactions within the random-phase approximation. This approach successfully highlights the dominance of the chiral $p$-wave pairing between electrons with the same spin and valley index at low densities, while also predicting the superconducting range in agreement with experimental findings. Furthermore, we examine the characteristics of distinct superconducting regions: SC1 and SC2 exhibit chiral finite-momentum superconductivity with pronounced phase fluctuations, whereas SC4 displays zero-momentum spin-singlet superconductivity.