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 Hartree-Fock 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.
|Journal||Physical Review Letters|
|State||Published - Mar 11 2022|
Bibliographical noteFunding Information:
The authors acknowledge supported from NSF DMR-1611161, German-Israeli Foundation (GIF) Grant No. I-1505-303.10/2019, Minerva Foundation, Dean of Faculty WIS, Israel planning and budgeting committee for financial support, and Koshland Foundation for Koshland Fellowship (A. D.), NSF DMR-2026947 (R. K. K.), and US-Israel Binational Science Foundation Grant No. 2016130 (G. M.). The authors thank Benjamin Sacépé, Alexis Coissard, Adolfo Grushin, and Cécile Repellin for stimulating conversations, and the Aspen Center for Physics (NSF Grant No. PHY-1607611) (R. K. K., G. M.) where this work was completed. We would also like to thank the University of Kentucky Center for Computational Sciences and Information Technology Services Research Computing for their support and use of the Lipscomb Compute Cluster and associated research computing resources.
© 2022 American Physical Society.
ASJC Scopus subject areas
- Physics and Astronomy (all)