Far-infrared photoresponse of the magnetoresistance of the two-dimensional electron systems in the integer quantized Hall regime

We have investigated the far-infrared (FIR) photoinduced resistance change of the two-dimensional electron systems in AlₓGa_1-xAs/GaAs heterojunctions in the integer quantized Hall regime. Sensitive photoinduced resistance change ΔRₓₓ is observed only in the vicinity of the quantum Hall states. It is found that the magnitude and polarity of ΔRₓₓ strongly depend on the Landau-level filling factor and the bias current. We have shown that not only a bolometric effect (i.e., electron heating) but also an electronic process due to edge channel transport is responsible for the observed behavior of ΔRₓₓ. The observed photoresponse can be used for realizing very sensitive, narrow-band FIR detectors.