Measurement of High Density Electrons Above a Helium Film on an Amorphous Metal Substrate

TL;DR

This study measures high-density two-dimensional electron systems on a helium film supported by an amorphous metal substrate, revealing the substrate's ability to sustain electron densities that may lead to Fermi degeneracy.

Contribution

First measurement of electron density on helium films supported by an amorphous metal substrate using Kelvin probe technique.

Findings

Supported high electron densities due to low surface roughness

Electrons are expected to be Fermi-degenerate at these densities

Amorphous metal substrate effectively supports uniform electron systems

Abstract

We have measured two-dimensional electron systems bound to a thin helium film supported by a metallic substrate. We report on our measurement of electron density obtained via a Kelvin probe technique. The underlying metallic substrate is an amorphous metallic alloy (TaWSi), which can support large uniform densities due to its low surface roughness and homogeneous work function. We find that this substrate is able to support high enough densities that the electrons are expected to be Fermi-degenerate.