Electronic Nematic States in Bernal Bilayer Graphene

In recent years, graphene multilayers under displacement field have demonstrated a wide variety of electronically ordered phases, including valley and/or spin polarized phases as well as potentially unconventional superconducting phases. Recent quantum oscillation data suggests that, in Bernal bilayer graphene (BBG), there is also an electronic nematic phase. In our work, we search for nematic phases in BBG under varying number density and displacement field by performing Hartree-Fock calculations. We first demonstrate that the screened Coulomb interaction is sufficient to induce a nematic order parameter, and also discuss the effects of coherence factors. We find partially polarized half and quarter metal states, which matches the experimental data, and discuss the presence of nematic order parameters within these states.