Charged complexes at the surface of liquid helium

TL;DR

This paper investigates charged clusters at the liquid helium surface, revealing a phase transition to a Wigner crystal that can be directly observed, differing from electron Wigner crystals.

Contribution

It introduces the formation and detection of a Wigner crystal of charged clusters on liquid helium, distinct from electron-based systems.

Findings

Charged clusters form a 2D system below helium surface.

A phase transition to a Wigner crystal occurs at high temperatures.

The Wigner lattice of clusters can be directly observed.

Abstract

Charged clusters in liquid helium in an external electric field form a two-dimensional system below the helium surface. This 2D system undergoes a phase transition from a liquid to a Wigner crystal at rather high temperatures. Contrary to the electron Wigner crystal, the Wigner lattice of charged clusters can be detected directly.