The main theme of this review is the many-body physics of vortices in quantum droplets of
bosons or fermions in the limit of small particle numbers. Systems of interest include cold …

Nonpolar atoms or molecules with low particle mass and weak inter-particle interactions can
form quantum liquids and solids (QLS) at low temperatures. Excess electrons naturally bind …

Electrons on helium form a unique two-dimensional system on the interface of liquid helium
and vacuum. A small number of trapped electrons on helium exhibits strong interactions in …

The image-charge detection provides a new direct method for the detection of the Rydberg
transition of electrons trapped on the surface of liquid helium. The interest in this method is …

The quantized lateral motional states and the spin states of electrons trapped on the surface
of superfluid helium have been proposed as basic building blocks of a scalable quantum …

We present transport measurements of a nondegenerate two-dimensional electron system
on the surface of liquid helium at a point constriction. The constriction is formed in a …

We report drastically different onset temperatures of the reentrant integer quantum Hall
states in the second and third Landau level. This finding is in quantitative disagreement with …

We present the results of a combined experimental and theoretical investigation of the
stability of rings of millimetric droplets bouncing on the surface of a vibrating liquid bath. As …

We investigate exciton bound‐state formation and crystallization effects in two‐dimensional
electron‐hole bilayers. Performing unbiased path integral Monte Carlo simulations all …

We demonstrate, for the first time, that a quasi-one-dimensional Wigner crystal formed on
superfluid He 4 with only a few electrons in the confined direction shows reentrant melting …