Terahertz Spectroscopy of Double CdTe/CdMgTe Quantum Wells

Modulation doped CdTe/CdMgTe double quantum wells were studied at low temperatures and high magnetic fields. Transmission of THz monochromatic radiation from a molecular laser was studied as a function of magnetic field on samples with a grid processed on the surface either by evaporation of metallic stripes or by etching stripe-like trenches which cut only the well positioned closer to the surface. We compare dispersion relations of THz excitations in these samples and in an unprocessed one and we show that the strength of magnetoplasmon excitations in samples studied can be considered as a promising basis to construct magnetic-field tunable THz detectors.