Tuesday, May 7, 2013

1305.0977 (P. Kühne et al.)

Isotropic and anisotropic Landau level transitions in epitaxial graphene
revealed by infrared optical Hall effect
   [PDF]

P. Kühne, V. Darakchieva, J. D. Tedesco, R. L. Myers-Ward, C. R. Eddy Jr., D. K. Gaskill, R. Yakimova, C. M. Herzinger, J. A. Woollam, M. Schubert, and T. Hofmann
We report on polarization property discrimination of inter Landau level transitions using reflection-type optical Hall effect measurements from 600 to 4000 cm-1 on epitaxial graphene grown by thermal decomposition of silicon carbide. We observe symmetric and anti-symmetric signatures in our data due to unpolarized, i.e., isotropic, and polarized, i.e., anisotropic Landau level transitions, respectively. The isotropic transitions shift with square-root magnetic field dependence typical for stacks of decoupled graphene mono-layers. The anisotropic Landau transitions match those previously observed in Bernal stacked bi-layer graphene, and predicted recently for Bernal stacked tri-layer graphene. The anisotropic signatures can be explained by coupling with free charge carrier magneto-optic plasma oscillations within the transition layer at the substrate graphene interface.
View original: http://arxiv.org/abs/1305.0977

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