Time- and Spectrally Resolved THz Photoconductivity in Quantum Hall Devices

The Terahertz photoconductivity is measured on GaAs/AlGaAs quantum Hall systems. Time resolved investigations show relaxation times form 10 to over 200ns and a dependence on the sample mobility and source-drain voltage. The latter is explained with a heating effect. In addition, spectrally resolved measurements are discussed. The spectral resolution is a function on the sample mobility. Finally, similar measurements on a HgTe/HgCdTe quantum well are presented. All results are important in respect to a possible THz detector application.