Transport Measurements of Strongly-Correlated Electrons on Helium in a Classical Point-Contact Device

TL;DR

This study investigates electron transport on liquid helium in a microchannel device with a split-gate, revealing stepwise current suppression influenced by electrostatic potentials and electron density, advancing mesoscopic electron experiments.

Contribution

It provides the first detailed analysis of electron transport through a split-gate constriction on helium, combining experimental measurements with finite element modeling.

Findings

Current decreases stepwise with negative split-gate voltage

Threshold current depends on surface electron density

Modeling agrees well with experimental data

Abstract

We present transport measurements of electrons on the surface of liquid helium in a microchannel device in which a constriction may be formed by a split-gate electrode. The surface electron current passing through the microchannel first decreases and is then completely suppressed as the split-gate voltage is swept negative. The current decreases in a steplike manner, due to changes in the number of electrons able to pass simultaneously through the constriction. We investigate the dependence of the electron transport on the AC driving voltage and the DC potentials applied to the sample electrodes, in order to understand the electrostatic potential profile of the constriction region. Our results are in good agreement with a finite element modeling analysis of the device. We demonstrate that the threshold of current flow depends not only on the applied potentials but also on the surface electron density. The detailed understanding of the characteristics of such a device is an important step in the development of mesoscopic experiments with surface electrons on liquid helium.