Mobility and Localization of Carriers in a Quasi-One-Dimensional Electron System over Liquid Helium

Abstract

The properties of a quasi-one-dimensional (Q1D) electron system on liquid helium are considered and the experiments on the carrier transport are presented. It has been shown that the electron mobility μ changes from high values close to that for bulk helium to very small values as a function of the Q1D channel width. Such a behaviour of μ is connected to a gradual transition from the regime of the quasi-free movement of the carriers in a Q1D system to the conditions of strong localization of the electrons. In the last case μ depends on temperature exponentially with the activation energy of a few degrees. It is predicted that in Q1D channels in regime of the localization two optical plasmon branches can exist. One of them (a high frequency branch) is connected with the oscillations of electrons in potential wells and another one has lower frequency and is due to the oscillations of dimples, which are created by localized electrons on the liquid helium surface, in the potential wells. Possible new experiments on study of magnetotransport, plasma oscillations and ”phase diagram” of ordered-disordered states in a Q1D electron system of a finite length over liquid helium are proposed and discussed.