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arXiv · 1201.0182

Terahertz dynamics of a topologically protected state: quantum Hall effect plateaus near cyclotron resonance in a GaAs/AlGaAs heterojunction

A. V. Stier·C. T. Ellis·H. Zhang·D. Eason·G. Strasser·B. D. McCombe T. Morimoto·H. Aoki·J. Cerne
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Abstract

We measure the Hall conductivity of a two-dimensional electron gas formed at a GaAs/AlGaAs heterojunction in the terahertz regime close to the cyclotron resonance frequency by employing a highly sensitive Faraday rotation method coupled with electrical gating of the sample to change the electron density. We observe clear plateau-and step-like features in the Faraday rotation angle vs. electron density and magnetic field (Landau-level filling factor), which are the high frequency manifestation of quantum Hall plateaus - a signature of topologically protected edge states. The results are compared to a recent dynamical scaling theory.

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A. V. Stier, C. T. Ellis, H. Zhang, D. Eason, G. Strasser, B. D. McCombe T. Morimoto, H. Aoki, J. Cerne. 2011-12-30. Terahertz dynamics of a topologically protected state: quantum Hall effect plateaus near cyclotron resonance in a GaAs/AlGaAs heterojunction. https://doi.org/10.1103/physrevlett.115.247401

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