Quasiperiodicity, band topology, and moiré graphene
arXiv:2011.06034 · doi:10.1103/PhysRevB.103.115110
Abstract
A number of moiré graphene systems have nearly flat topological bands where electron motion is strongly correlated. Though microscopically these systems are only quasiperiodic, they can typically be treated as translation invariant to an excellent approximation. Here we reconsider this question for magic angle twisted bilayer graphene that is nearly aligned with a hexagonal boron nitride(h-BN) substrate. We carefully study the effect of the periodic potential induced by h-BN on the low energy physics. The combination of this potential and the moiré lattice produced by the twisted graphene generates a quasi-periodic term that depends on the alignment angle between h-BN and the moiré graphene. We find that the alignment angle has a significant impact on both the band gap near charge neutrality and the behavior of electrical transport. We also introduce and study toy models to illustrate how a quasi-periodic potential can give rise to localization and change in transport properties of topological bands.
12+8 pages
References in corpus (5)
- Origin of band gaps in graphene on hexagonal boron nitride
- Entanglement Spectrum of a Disordered Topological Chern Insulator
- Anderson localization transitions with and without random potentials
- Symmetry breaking in the double moiré superlattices of relaxed twisted bilayer graphene on hexagonal boron nitride
- Misalignment instability in magic-angle twisted bilayer graphene on hexagonal boron nitride