IMAGING OF A SUSPENDED HELIUM FILM WITH 2-D ELECTRONS BY INTERFEROMETRY

A helium film suspended between elevations on a substrate forms an exc ellent surface for a two-dimensional electron gas. With the structure on the substrate a quasi one-dimensional electron system can be create d. Experiments probing the electrical transport properties of this sys tem have raised questions about the suspended helium film itself. We r eport measurements of the suspended film using interferometry. The pro file is mapped out as a function of the bull helium level beneath the substrate. By measuring the electron signal simultaneously the relatio n between the signal and the film profile can be obtained.