2013/10/31 by Xi Chen, John R. Wallbank, J. R. Wallbank +8
Materials Science · Physics and Astronomy · #Condensed matter physics #Graphene #Graphene research and applications #Magnetic field #Noncommutative and Quantum Gravity Theories #Physics #Quantum mechanics #Superlattice #Topological Materials and Phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.89.075401
published as Physical Review B 89, 075401 (2014) · 5 pages, 4 figures
arxiv created 2014/01/13 · openalex publication_date 2014/02/05 · arxiv updated 2014/02/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We find a systematic reappearance of massive Dirac features at the edges of consecutive minibands formed at magnetic fields Bp/q=(p)/(q)\ensuremathφ0/S providing rational magnetic flux through a unit cell of the moir'e superlattice created by a hexagonal substrate for electrons in graphene. The Dirac-type features in the minibands at B=Bp/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 Bp/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.