Production of a degenerate Fermi gas of metastable helium-3 atoms

TL;DR

This paper reviews experiments on ultracold metastable helium-3 and helium-4 gases, including Bose-Einstein condensation, sympathetic cooling to Fermi degeneracy, and ionization loss studies.

Contribution

It reports the first production of a degenerate Fermi gas of metastable helium-3 atoms and details experimental techniques and results.

Findings

Achieved Bose-Einstein condensation of helium-4 with over 10 million atoms.

Realized sympathetic cooling of helium-3 to below the Fermi temperature with over 1 million atoms.

Studied Penning ionization losses in ultracold helium gases.

Abstract

We give an overview of the experiments at the Laser Centre of the Vrije Universiteit in Amsterdam on ultracold gases of metastable helium-4 and helium-3 as well as mixtures of both isotopes. We describe our experimental setup and discuss our experiments on Bose-Einstein condensation of 4He* (more than 10 million atoms in a BEC) and sympathetic cooling of 3He* towards Fermi degeneracy (more than 1 million atoms below the Fermi temperature as well as realization of a degenerate boson-fermion mixture). We also present our results on Penning Ionization in ~1 mK clouds containing a single isotope (homonuclear losses) or a mixture of both isotopes (heteronuclear losses).