Quantum Monte Carlo study of superconductivity in rhombohedral trilayer graphene under an electric field

TL;DR

This study uses quantum Monte Carlo simulations to explore how an electric field influences superconductivity and magnetic properties in trilayer graphene, revealing dominant $d+id$ pairing driven by electronic correlations.

Contribution

It provides the first systematic quantum Monte Carlo analysis of superconductivity in rhombohedral trilayer graphene under electric fields, highlighting the role of Coulomb interactions.

Findings

Electric field suppresses antiferromagnetism, especially long-range correlations.

$d+id$ superconducting pairing is dominant and enhanced by increased Coulomb interaction.

Results may explain recent experimental observations of superconductivity in the material.

Abstract

By using the constrained-phase quantum Monte Carlo method, we performed a systematic study of the ground state of the half filled Hubbard model for a trilayer honeycomb lattice. We analyze the effect of the perpendicular electric field on the electronic structure, magnetic property and pairing correlations. It is found that the antiferromagnetism is suppressed by the perpendicular electric field, especially the long-range parts, and the dominant magnetic fluctuations are still antiferromagnetic. The electronic correlation drives a $d+id$ superconducting pairing to be dominant over other pairing patterns among various electric fields and interaction strengths. We also found that the $d+id$ pairing correlation is greatly enhanced as the on-site Coulomb interaction is increased. Our intensive numerical results may unveil the nature of the recently observed superconductivity in rhombohedral trilayer graphene under an electric field.