Thursday, May 28, 2015

Abstract-Terahertz response of patterned epitaxial graphene

Christian Sorger, Sascha Preu1,2, Johannes Schmidt3, Stephan Winnerl3, Yuliy V Bludov4, Nuno M R Peres4, Mikhail I Vasilevskiy4 and Heiko B Weber1
1 Department of Physics, Friedrich-Alexander-University Erlangen-Nuremberg (FAU), Staudtstraße 7, D-91058 Erlangen, Germany
2 Department of Electrical Engineering and Information Technology, Technical University Darmstadt, Merckstraße 25, D-64283 Darmstadt, Germany
3 Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, D-01314 Dresden, Germany
4 Department of Physics and Center of Physics, University of Minho, Campus de Gualtar, P-4710-057 Braga, Portugal 

We study the interaction between polarized terahertz (THz) radiation and micro-structured large-area graphene in transmission geometry. In order to efficiently couple the radiation into the two-dimensional material, a lateral periodic patterning of a closed graphene sheet by intercalation doping into stripes is chosen. We observe unequal transmittance of the radiation polarized parallel and perpendicular to the stripes. The relative contrast, partly enhanced by Fabry–Perot oscillations reaches 20%. The effect even increases up to 50% when removing graphene stripes in analogy to a wire grid polarizer. The polarization dependence is analyzed in a large frequency range from <80 GHz to 3 THz, including the plasmon–polariton resonance. The results are in excellent agreement with theoretical calculations based on the electronic energy spectrum of graphene and the electrodynamics of the patterned structure.

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