MOBILITY OF ELECTRONS ON A HELIUM FILM CAPILLARY CONDENSED ON A 2D-GRATING

Recent developments in the research on two-dimensional electron system s (2DES) show a trend to bring structure in the 2DES and/or reduce the dimensionality. By applying helium films on a substrate with elevatio ns, thick films are created by capillary condensation, with the struct ure of the elevations imposed on the 2DES. We present the first result s of electrons on films above a two-dimensional dielectric grating. Th e two-dimensional superstructure still allows the use of an overall Co rbino arrangement. Thus absolute and accurate values for the mobility of the electrons could be obtained. The measured equilibrium mobility of the electrons at a temperature of 2 K is 0.25 m(2)/Vs, which is one order of magnitude below the value for the mobility on bulk liquid he lium, that was expected.