Zusammenfassung
Studying the cyclotron resonance (CR) induced photoconductivity in GaAs and HgTe two-dimensional electron structures under circularly polarized terahertz illumination, we observed an anomalous resonant photoresponse for the CR inactive helicity of almost the same magnitude as for the CR active helicity. This observation conflicts with simultaneous transmission measurements and fundamentally ...
Zusammenfassung
Studying the cyclotron resonance (CR) induced photoconductivity in GaAs and HgTe two-dimensional electron structures under circularly polarized terahertz illumination, we observed an anomalous resonant photoresponse for the CR inactive helicity of almost the same magnitude as for the CR active helicity. This observation conflicts with simultaneous transmission measurements and fundamentally contradicts the conventional theory of CR. We provide a possible route to explain such a basic failure of the conventional description of light-matter interaction and discuss a modified electron dynamics near strong impurities that may provide a local near-field coupling of the two helicity modes. This should result in a CR enhanced absorption for both magnetic field polarities.