Abstract
Single-photon detection of THz waves is realized by using two kinds of detectors. The first type of detector exploits a semiconductor lateral quantum dot in magnetic fields. The quantum dot is operated as a single electron transistor (SET) to detect individual events of THz-photon absorption (1.5 THz-1.9 THz) due to cyclotron-resonance induced intra-dot polarization. The second type detector utilizes parallel double quantum dots, in which one of the quantum dots serve as an SET while the other quantum dot affects the SET conductance when it is ionized by a THz photon absorption (about 0.5 THz). The detector performance is described. A future perspective for further improvements of the detectors is also briefly given.
