NONLINEAR MOBILITY OF 2-DIMENSIONAL ELECTRON LAYER OVER LIQUID-HELIUM

The dependence of the mobility on driving electric field for electrons localized in two-dimensional electron layer over liquid helium surfac e is studied experimentally at temperatures below 1 K in the region of electron-ripplon scattering. The measurements are carried out at elec tron concentrations lower than those leading to a screening the holdin g electric field by the field of electron layer (unsaturated case). Th e electron mobility in ground surface level is shown to be monotonical ly increasing function of driving field. The results of the investigat ion agree with theoretical dependences obtained under the supposition of coinciding the short-wave region of ripplon spectrum with long-wave asymptotics.