Dirac edges of fractal magnetic minibands in graphene with hexagonal moire superlattices

Chen, Xi and Wallbank, John and Patel, Aavishkar A. and Mucha-Kruczynski, Marcin and McCann, Edward and Falko, Vladimir (2014) Dirac edges of fractal magnetic minibands in graphene with hexagonal moire superlattices. Physical review B, 89 (7). ISSN 1098-0121

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Abstract

We find a systematic reappearance of massive Dirac features at the edges of consecutive minibands formed at magnetic fields B_{p/q}=\frac{p}{q}\phi_0/S providing rational magnetic flux through a unit cell of the moire superlattice created by a hexagonal substrate for electrons in graphene. The Dirac-type features in the minibands at B=B_{p/q} determine a hierarchy of gaps in the surrounding fractal spectrum, and show that these minibands have topological insulator properties. Using the additional q-fold degeneracy of magnetic minibands at B_{p/q}, we trace the hierarchy of the gaps to their manifestation in the form of incompressible states upon variation of the carrier density and magnetic field.

Item Type: Journal Article
Journal or Publication Title: Physical review B
Additional Information: ©2014 American Physical Society
Departments: Faculty of Science and Technology > Physics
ID Code: 68521
Deposited By: ep_importer_pure
Deposited On: 07 Feb 2014 15:28
Refereed?: Yes
Published?: Published
Last Modified: 20 Feb 2020 01:57
URI: https://eprints.lancs.ac.uk/id/eprint/68521

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