Production of quantum-degenerate strontium gases: Larger, better, faster, colder
We report on an improved scheme to generate Bose-Einstein condensates (BECs) and degenerate Fermi gases of strontium. This scheme allows us to create quantum gases with higher atom number, a shorter time of the experimental cycle, or deeper quantum degeneracy than before. We create a BEC of 84Sr exceeding 107 atoms, which is a 30-fold improvement over previously reported experiments. We increase the atom number of 86Sr BECs to 2.5x104 (a fivefold improvement), and refine the generation of attractively interacting 88Sr BECs. We present a scheme to generate 84Sr BECs with a cycle time of 2s, which, to the best of our knowledge, is the shortest cycle time of BEC experiments ever reported. We create deeply-degenerate 87Sr Fermi gases with T/TF as low as 0.10(1), where the number of populated nuclear spin states can be set to any value between one and ten. Furthermore, we report on a total of five different double-degenerate Bose-Bose and Bose-Fermi mixtures. These studies prepare an excellent starting point for applications of strontium quantum gases anticipated in the near future.
Phase transition from a thermal gas to a 84Sr BEC with 107 atoms.
Simon Stellmer, Rudolf Grimm, and Florian Schreck