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
ID Code:
68521
Deposited By:
Deposited On:
07 Feb 2014 15:28
Refereed?:
Yes
Published?:
Published
Last Modified:
24 Oct 2020 03:01