TY - JOUR

T1 - Dirac edges of fractal magnetic minibands in graphene with hexagonal moire superlattices

AU - Chen, Xi

AU - Wallbank, John

AU - Patel, Aavishkar A.

AU - Mucha-Kruczynski, Marcin

AU - McCann, Edward

AU - Falko, Vladimir

N1 - ©2014 American Physical Society

PY - 2014/2/5

Y1 - 2014/2/5

N2 - 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.

AB - 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.

U2 - 10.1103/PhysRevB.89.075401

DO - 10.1103/PhysRevB.89.075401

M3 - Journal article

VL - 89

JO - Physical review B

JF - Physical review B

SN - 1098-0121

IS - 7

M1 - 075401

ER -