Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 9: Poster 1
HL 9.76: Poster
Montag, 23. März 2009, 14:30–17:00, P2
Microwave Spectroscopy of Confined and Edge Magnetoplasmons in 2D Electron Stripes — •Tobias Krohn1, Nikolai Mecking1, Matthias Wiemann2, Ulrich Kunze2, Johannes Kunze3, Christian Heyn1, and Detlef Heitmann1 — 1Institut für Angewandte Physik, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg — 2Lehrstuhl für Werkstoffe und Nanoelektronik, Ruhr-Universität Bochum, 44780 Bochum — 3Lehrstuhl für Integrierte Systeme, Ruhr-Universität Bochum, 44780 Bochum
We have investigated the photovoltage that was induced by irradiating microwaves on typically 30 x 60 µm2 stripes containing a two-dimensional electron system (2DES) in a modulation-doped AlGaAs/GaAs heterostructure. The experiments were performed in sweeps of a magnetic field B that was applied perpendicularly with respect to the 2DES. The temperature was 4.2 K.
Our set up allows us to investigate a wide frequency range from 9 GHz to 325 GHz. We use special frequency modulation techniques to reduce impedance matching effects in the microwave setup. We observe a rich mode spectrum with modes exhibiting positive or negative B dispersions, which we can model, respectively, by confined magnetoplasmon and edge magnetoplasmon modes. Both types of modes are governed by characteristic lengths. We find that these lengths reflect the stripe’s dimensions.
We gratefully acknowledge support through SFB 508 and BMBF 01BM461.