Coexistence of Canted Antiferromagnetism and Bond Order in ν=0 Graphene

Motivated by experimental studies of graphene in the quantum Hall regime, we revisit the phase diagram of a single sheet of graphene at charge neutrality. Because of spin and valley degeneracies, interactions play a crucial role in determining the nature of the ground state. We show that, generically within the HartreeFock approximation, in the regime of interest there is a region of coexistence between magnetic and bond orders in the phase diagram. We demonstrate this result both in continuum and lattice models, and argue that the coexistence phase naturally provides a possible explanation for unreconciled experimental observations on the quantum Hall effect in graphene.

Automated summary

Motivated by experiments on graphene in the quantum Hall regime, this study revisits the phase diagram of a single sheet of graphene at charge neutrality and presents the finding of a coexistence region of magnetic and bond orders. This result provides a possible explanation for experimental observations on the quantum Hall effect in graphene.