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

Abstract

We have investigated the far-infrared (FIR) photoinduced resistance change of the two-dimensional electron systems in ${\mathrm{Al}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}/\mathrm{GaAs}$ heterojunctions in the integer quantized Hall regime. Sensitive photoinduced resistance change $\ensuremath{\Delta}{R}_{\mathrm{xx}}$ is observed only in the vicinity of the quantum Hall states. It is found that the magnitude and polarity of $\ensuremath{\Delta}{R}_{\mathrm{xx}}$ 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 $\ensuremath{\Delta}{R}_{\mathrm{xx}}.$ The observed photoresponse can be used for realizing very sensitive, narrow-band FIR detectors.