Superfluid Helium Drops Levitated in High Vacuum

TL;DR

This paper reports the successful trapping and cooling of millimeter-scale superfluid helium drops in high vacuum, enabling new experiments in superfluid physics, cold chemistry, and optomechanics.

Contribution

It introduces a novel method for trapping superfluid helium drops in high vacuum, combining multiple techniques for extended isolation and optical mode hosting.

Findings

Drops remain trapped indefinitely in high vacuum.

Drops cooled to 330 mK by evaporation.

Hosting of optical whispering gallery modes.

Abstract

We demonstrate the trapping of millimeter-scale superfluid Helium drops in high vacuum. The drops are sufficiently isolated that they remain trapped indefinitely, cool by evaporation to 330 mK, and exhibit mechanical damping that is limited by internal processes. The drops are also shown to host optical whispering gallery modes. The approach described here combines the advantages of multiple techniques, and should offer access to new experimental regimes of cold chemistry, superfluid physics, and optomechanics.