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L. Chizhova, J. Burgdörfer, F. Libisch:
"Magneto-optical response of graphene: Probing substrate interactions";
Physical Review B, 92 (2015), S. 125411-1 - 125411-8.

Magneto-optical transitions between Landau levels can provide precise spectroscopic information on the electronic structure and excitation spectra of graphene, enabling probes of substrate and many-body effects. We calculate the magneto-optical conductivity of large-size graphene flakes using a tight-binding approach. Our method allows us to directly compare the magneto-optical response of an isolated graphene flake with one aligned on hexagonal boron nitride giving rise to a periodic superlattice potential. The substrate interaction induces band gaps away from the Dirac point. In the presence of a perpendicular magnetic field, Landau-level-like structures emerge from these zero-field band gaps. The energy dependence of these satellite structures is, however, not easily accessible by conventional probes of the density of states by varying the back-gate voltage. Here we propose the magneto-optical probing of the superlattice perturbed spectrum. Our simulation includes magneto-excitonic effects in first-order perturbation theory. Our approach yields a quantitative explanation of recently observed Landau-level-dependent renormalizations of the Fermi velocity.

Graphene, Boron Nitride, Moire Structure, Optical Response

http://dx.doi.org/10.1103/PhysRevB.92.125411

http://publik.tuwien.ac.at/files/PubDat_246450.pdf