AVS 61st International Symposium & Exhibition
    Spectroscopic Ellipsometry Focus Topic Thursday Sessions
       Session EL+AS+EM+MC+SS-ThA

Paper EL+AS+EM+MC+SS-ThA9
Dielectric Tensor Model for Inter Landau-level Transitions in Highly Oriented Pyrolytic Graphite and Epitaxial Graphene – Symmetry Properties, Energy Conservation and Plasma Coupling

Thursday, November 13, 2014, 5:00 pm, Room 304

Session: Optical Characterization of Nanostructures and Metamaterials
Presenter: Philipp Kühne, Linköping University, Sweden
Authors: P. Kühne, Linköping University, Sweden
T. Hofmann, University of Nebraska-Lincoln
M. Schubert, University of Nebraska-Lincoln
C.M. Herzinger, J.A. Woollam Co., Inc.
V. Darakchieva, Linköping University, Sweden
Correspondent: Click to Email
We report on polarization sensitive, magneto-optic, reflection-type Landau level (LL) spectroscopy at low temperatures by using the integrated optical Hall effect instrument1 in the mid-infrared spectral range (600 – 4000 cm−1) on highly oriented pyrolytic graphite (HOPG) and epitaxial graphene grown on C-face silicon carbide by thermal decomposition. In both sample systems we observe a multitude of inter-LL transitions. Inter-LL transitions in HOPG possess polarization mode mixing polarization selection rules characteristics, while polarization mode conserving and polarization mode mixing inter-LL transitions are observed in epitaxial graphene which can be assigned to single- and Bernal stacked (ABA) multi-layer graphene, respectively.2 We present a new dielectric tensor model for inter-LL transitions which explains all experimentally observed line-shapes. For inter-LL transitions in multi-layer graphene and HOPG we employ this new model together with energy conservation considerations, to show that these polarization mode mixing inter-LL transitions couple with a free charge carrier plasma. Finally, inter-LL transition energy parameters are determined and discussed.

1) P. Kühne, et. al., Rev. Sci. Instrum., accepted (2014)

2) P. Kühne, et. al., Phys. Rev. Lett. 111, 077402 (2013)