Double quantum dots as a high sensitive submillimeter-wave detector

A single-electron transistor (SET) consisting of parallel double quantum do ts fabricated in a GaAs/AlxGa1-xAs heterostructure crystal is demonstrated and it serves as an extremely high sensitive detector of submillimeter wave s (SMMWs). One of the double dots is ionized by a SMMW via Kohn-mode plasma excitation, which affects the SET conductance through the other quantum do t, yielding the photoresponse. The noise equivalent power of the detector f or wavelengths of about 0.6 mm is estimated to reach the order of 10(-17) W root Hz at 70 mK. (C) 2001 American Institute of Physics.