Disorder-tuned selection of ordered state in bilayer graphene*

The nature of the symmetry-broken state driven by interaction in bilayer graphene (BLG) has attracted a lot of interest. Theoretical studies predict various possible ordered phases as the candidate for the ground state of BLG. To identify what instability is the most favorable in BLG, a number of experiments have been performed by several groups. However, there is no consensus: some experiments show evidence for a fully gapped state while others seem more consistent with a nematic state. By exploring the influence of disorder on a variety of competing ordered states, we find that the pair breaking effect due to disorder varies among the candidate phases, giving rise to different amount of suppression on the mean-field transition temperatures. This suggests a simple and natural scenario to resolve the discrepancy between experimental observations.