Terahertz Detectors Based on Plasmonic Excitations in Double CdTe/CdMgTe Quantum Wells

Double CdTe/CdMgTe quantum wells modulation doped with Iodine were etched to fabricate grids with a period of $8 \mu \mathrm{m}$ and a geometrical aspect ratio ($\delta$) between 0.2 and 0.7. Etching removed only the well closer to the sample's surface. Transmission of terahertz radiation as a function of magnetic field (B) up to 10 T was measured at 2 K. The spectra show a single magnetoplasmon resonance (MPR) which position in B depends on $\delta$. A huge amplitude of MPR, comparable to that of the cyclotron resonance, allows us to propose such structures as tunable plasmonic terahertz detectors.