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HL: Fachverband Halbleiterphysik
HL 59: THz and MIR physics in semiconductors
HL 59.3: Vortrag
Donnerstag, 19. März 2020, 10:00–10:15, POT 151
Modeling of the Hot Carrier Dynamics in Graphene THz Magneto Plasmons — •Florian Stawitzki1, Sebastian Matschy1, Stephan Winnerl2, Matt Chin3, 4, Thomas E. Murphy4, and Martin Mittendorff1 — 1Universität Duisburg-Essen, Duisburg, Germany — 2Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany — 3US Army Research Laboratory — 4University of Maryland, College Park, MD, US
Patterning graphene in plasmonic structures leads to resonant absorption and an increased light-matter interaction that also results in enhanced THz non-linear absorption. The charge carriers in graphene can be heated efficiently, leading to a decrease in chemical potential. This causes an ultrafast redshift of the plasmon frequency, and thus a strong increase in transmission at the resonance frequency. Here we study the dynamics of THz plasmons in an array of micrometer sized discs of bilayer graphene on SiC. These plasmons hybridize with the cyclotron motion in strong magnetic fields leading to splitting of the plasmon resonance into two branches that can be distinguished with circularly polarized radiation. We experimentally and theoretically investigate the nonlinear absorption in magnetic fields of up to 10T. A two-temperature model is used to simulate the time dependent temperature of the charge carriers. The results are in good agreement with pump-probe measurements performed at the free-electron laser FELBE at HZDR.
We thank the German Research Foundation for funding through CRC 1242.