Electrically controllable magnetic order in the bilayer Hubbard model on honeycomb lattice --- a determinant quantum Monte Carlo study

TL;DR

This study uses determinant quantum Monte Carlo to investigate how an electric field influences magnetic order in a bilayer Hubbard model on a honeycomb lattice, revealing a suppression of magnetic order with increasing electric field.

Contribution

It provides the first unbiased quantum Monte Carlo analysis of electric field effects on magnetic order in the bilayer Hubbard model on a honeycomb lattice.

Findings

Magnetic order supports the layered antiferromagnetic spin density wave ground state.

Magnetic moments are smaller than mean field estimates.

Magnetic order parameter decreases rapidly with increasing electric field.

Abstract

Layered antiferromagnetic spin density wave (LAF) state is one of the plausible ground states of charge neutral Bernal stacked bilayer graphene. In this paper, we use determinant quantum Monte Carlo method to study the effect of the electric field on the magnetic order in bilayer Hubbard model on a honeycomb lattice. Our results qualitatively support the LAF ground state found in the mean field theory. The obtained magnetic moments, however, are much smaller than what are estimated in the mean field theory. As electric field increases, the magnetic order parameter rapidly decreases.