Unusual magnetotransport in twisted bilayer graphene
arXiv:2105.01870 · doi:10.1073/pnas.2118482119
Abstract
We present transport measurements of bilayer graphene with 1.38° interlayer twist and apparent additional alignment to its hexagonal boron nitride cladding. As with other devices with twist angles substantially larger than the magic angle of 1.1°, we do not observe correlated insulating states or band reorganization. However, we do observe several highly unusual behaviors in magnetotransport. For a large range of densities around half filling of the moiré bands, magnetoresistance is large and quadratic. Over these same densities, the magnetoresistance minima corresponding to gaps between Landau levels split and bend as a function of density and field. We reproduce the same splitting and bending behavior in a simple tight-binding model of Hofstadter's butterfly on a square lattice with anisotropic hopping terms. These features appear to be a generic class of experimental manifestations of Hofstadter's butterfly and may provide insight into the emergent states of twisted bilayer graphene.
8 pages, 4 figures; updated supplemental material; added additional device measurements and updated toy model
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Cited by in corpus (17)
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- Quantifying the charge carrier interaction in metallic twisted graphene superlattices
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- Revisiting Bloch electrons in magnetic field: Hofstadter physics via hybrid Wannier states
- Atomistic theory of moiré Hofstadter's butterfly in magic-angle graphene
- Inducing topological flat bands in bilayer graphene with electric and magnetic superlattices
- Landau quantization near generalized Van Hove singularities: Magnetic breakdown and orbit networks
- Feedback Lock-in: A versatile multi-terminal measurement system for electrical transport devices
- Mean-field Modelling of Moiré Materials: A User's Guide with Selected Applications to Twisted Bilayer Graphene
- Microscopic theory for electron-phonon coupling in twisted bilayer graphene
- Residual quantum coherent electron transport in doped graphene leads
- Engineering stacking-induced topological phase transitions in bilayer heterostructures