We report on polarization selection rules 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 polarization preserving and polarization mixing inter-Landau level transitions, respectively. From field-dependent measurements we identify that transitions in decoupled graphene mono-layers are governed by polarization mixing selection rules, whereas transitions in coupled graphene mono-layers are governed by polarization preserving selection rules. The selection rules may find explanation by different coupling mechanisms of inter-Landau level transitions with free charge carrier magneto-optic plasma oscillations.
@article{arxiv.1305.0977,
title = {Polarization selection rules for inter-Landau level transitions in epitaxial graphene revealed by infrared optical Hall effect},
author = {P. Kühne and V. Darakchieva and J. D. Tedesco and R. L. Myers-Ward and C. R. Eddy and D. K. Gaskill and R. Yakimova and C. M. Herzinger and J. A. Woollam and M. Schubert and T. Hofmann},
journal= {arXiv preprint arXiv:1305.0977},
year = {2013}
}