Theoretical study of correlated electronic states in twisted monolayer-bilayer graphene*

In twisted trilayer graphene with a graphene monolayer stacked and twisted on top of bilayer graphene, massless and massive Dirac fermions hybridize. This heterostructure gives rise to topological electronic bands that are a unique platform to explore symmetry-broken correlated electronic states [1,2,3]. In this theoretical work, we first develop an analytical model to explain the observed asymmetry in formation of correlated states with respect to carrier density and displacement field. Using the linearized gap equation method, we then calculate the stability and critical temperature for different symmetry breaking phases, including spin density waves, charge density waves, and valley ordered phases.
References
[1] Shi, Yanmeng, et al. "Tunable van Hove Singularities and Correlated States in Twisted Trilayer Graphene." arXiv preprint arXiv:2004.12414 (2020).
[2] Chen, Shaowen, et al. "Electrically tunable correlated and topological states in twisted monolayer-bilayer graphene." arXiv preprint arXiv:2004.11340 (2020).
[3] Polshyn, Hryhoriy, et al. "Nonvolatile switching of magnetic order by electric fields in an orbital Chern insulator." arXiv preprint arXiv:2004.11353 (2020).