Nonlinear phenomena in the mobility of two-dimensional electron layer at the liquid helium surface

Abstract

The dependence of the mobility of electrons localized in a two-dimensional charged layer at the liquid helium surface on the driving electric field is investigated experimentally below 1 K in the electron–ripplon scattering region. The measurements were made at electron concentrations smaller than the values corresponding to screening of confining electric field by the field of the electron layer (below saturation). The form of the observed dependence of mobility on the driving field indicates that the two-ripplon mechanism of energy relaxation plays a decisive role in the system of surface electrons under superheating conditions. Experimental results are in accord with theoretical dependences obtained under the assumption that the short-wave ripplon spectral region coincides with the long-wave asymptotic form.