Photoconductivity of 2<Emphasis Type="Italic">D</Emphasis> electrons over helium in the presence of cyclotron pumping

Recent measurements of photoconductivity for 2D electrons at the helium surface in the presence of a magnetic field orthogonal to the 2D plane require a qualitative explanation, because of the very fact of its existence. Various scenarios of the effect are discussed, and arguments in favor of one of these—that which is associated with the emergence of thermoelectric power along a 2D charged system in a magnetic field under the effect of a spatially nonuniform external pumping—are presented. The corresponding nonuniform electron distribution δn_s (against the background of the uniform distribution) leads to the effect that is observed with the aid of Corbino disks and which consists in a change in the conductivity of the 2D system.