Differential measurements of the lateral photoeffect in GaAs/AlGaAs heterostructures

The authors present a novel laserscan technique based on the lateral photoeffect to image the local resistivity of the two-dimensional electron gas of GaAs/AlGaAs heterostructures. They show that a measurement of the spatial derivative of the lateral photoeffect gives direct information about the local resistivity. Compared with conventional measurements of the lateral photoeffect the technique presented here is able to resolve much smaller variations in the resistivity. This is illustrated by the experimental results presented.