Abstract
Optical Hall conductivity is measured from the Faraday rotation for a heterojunction quantum Hall system in the terahertz-frequency regime. The Faraday rotation angle ( fine-structure constant ) is found to significantly deviate from the Drude-like behavior to exhibit a plateaulike structure around the Landau-level filling . The result, which fits with the behavior expected from the carrier localization effect in the ac regime, indicates that the plateau structure, although not quantized, still exists in the terahertz regime.
- Received 29 March 2010
DOI:https://doi.org/10.1103/PhysRevLett.104.256802
©2010 American Physical Society