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

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 analyse the effect of the perpendicular electric field on the electronic structure, magnetic property and pairing correlations. It is found that antiferromagnetic fluctuations emerge with the perpendicular electric field, and 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.