Regensburg 2013 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 45: Transport in high magnetic fields / Quantum Hall effect
HL 45.4: Talk
Tuesday, March 12, 2013, 15:45–16:00, H13
Optically induced ballistic transport in edge channels — Christoph Kastl1, Markus Stallhofer1, •Christoph Karnetzky1, Dieter Schuh2, Werner Wegscheider3, and Alexander Holleitner1 — 1Walter Schottky Institut and Physik-Department, TU München — 2Institut für Experimentelle und Angewandte Physik, Universität Regensburg — 3Laboratorium für Festkörperphysik, ETH Zürich, Switzerland
We use GaAs-based quantum point contacts as energy tunable and spin-sensitive detectors for an optically induced charge carrier ensemble in a two-dimensional electron gas. Using this technique, we recently investigated spatially resolved photocurrent flow patterns in a mesoscopic circuit with a moderate perpendicular magnetic field applied [1]. At high magnetic fields, where Landau-quantization applies, we find a substantially enhanced propagation length compared to zero field [2] along the boundary of the circuit. We explain the findings in the framework of charge carrier transport within one-dimensional quantum Hall edge states. The presented technique principally allows for the selective optical excitation and electronic detection of spin-degenerate edge channels [3].
M. Stallhofer et al., Phys. Rev. B 86, 115315 (2012).
M. Stallhofer et al., Phys. Rev. B 86, 115313 (2012).
C. Kastl et al. (2013).