NONLINEAR PHENOMENA IN MOBILITY OF 2-DIME NSIONAL ELECTRON-SYSTEM ON THE LIQUID-HELIUM SURFACE

The dependence of the mobility on driving electric field for electrons localized in two-dimensional electron layer on the liquid helium surf ace has been studied at temperatures below 1 K in the region of electr on-ripplon scattering. The measurements are carried out at electron co ncentrations lower than those leading to screening the holding electri c field by the field of electron layer (unsaturated case). The charact er of the dependence of mobility on driving field is shown to be a res ult of determining contribution of two-ripplon mechanism of energy rel axation in surface electron system under its overheating. The data obt ained agree with theoretical dependences obtained under the suppositio n of coinciding the short-wave region of ripplon spectrum with long- w ave asymptotics.