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  • Letter
  • Open Access

High phase-space density gas of NaCs Feshbach molecules

Aden Z. Lam1, Niccolò Bigagli1, Claire Warner1, Weijun Yuan1, Siwei Zhang1, Eberhard Tiemann2, Ian Stevenson1, and Sebastian Will1,*

  • 1Department of Physics, Columbia University, New York, New York 10027, USA
  • 2Institut für Quantenoptik, Leibniz Universität Hannover, 30167 Hannover, Germany

  • *sebastian.will@columbia.edu
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Phys. Rev. Research 4, L022019 – Published 25 April, 2022

DOI: https://doi.org/10.1103/PhysRevResearch.4.L022019

Abstract

We report on the creation of ultracold gases of bosonic Feshbach molecules of NaCs. The molecules are associated from overlapping gases of Na and Cs using a Feshbach resonance at 864.12(5)G. We characterize the Feshbach resonance using bound-state spectroscopy, in conjunction with a coupled-channel calculation. By varying the temperature and atom numbers of the initial atomic mixtures, we demonstrate the association of NaCs gases over a wide dynamic range of molecule numbers and temperatures, reaching 70 nK for our coldest systems and a phase-space density near 0.1. This is an important stepping stone for the creation of degenerate gases of strongly dipolar NaCs molecules in their absolute ground state.

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Phys. Rev. Research 4, L022019– Published 25 April, 2022
  • Received 8 February 2022
  • Accepted 29 March 2022
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