Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 48: Two-dimensional materials IV (joined session with TT)

HL 48.1: Talk

Wednesday, March 22, 2017, 09:30–09:45, POT 51

Landau-Quantized Graphene: A Tunable Nonlinear Optical Material in the THz Range — •Jacob C. König-Otto^1,2, Yongrui Wang³, Alexey Belyanin³, Claire Berger^4,5, Walt A. de Heer⁴, Milan Orlita^6,7, Alexej Pashkin¹, Harald Schneider¹, Manfred Helm^1,2, and Stephan Winnerl¹ — ¹Helmholtz-Zentrum Dresden-Rossendorf, Germany — ²Technische Universität Dresden, Germany — ³Texas AM University, USA — ⁴Georgia Institute of Technology, USA — ⁵CNRS-Université Alpes, France — ⁶LNCMI, Grenoble, France — ⁷Charles University in Prague, Czech Republic

Finding nonlinear optical materials for the THz and mid-infrared regimes is not straightforward. State-of-the-art devices with a high third-order optical susceptibility are often processed as complex multi-quantum-well structures designed to feature one specific resonance frequency. In our work we study Landau-quantized graphene as a tunable and simple to produce nonlinear material. To this end we perform time-integrated degenerate four-wave mixing (FWM) experiments at a photon energy of 78 meV resonant to the transitions between the Landau levels LL₋₁, LL₀ and LL₁ at a magnetic field of roughly 4 T. We can recover expected scaling of the FWM-signal with the incident fields and the resonance behavior. The value of the third-order surface susceptibility in this material is in agreement with our calculations based on the density matrix formalism. We find the order of χ⁽³⁾ of Landau-quantized graphene to be competitive with more complex and elaborated solutions.