title: Improved Radio-Frequency Magneto-Optical Trap of SrF Molecules.
abstract: We report the production of ultracold, trapped strontium monofluoride (SrF) molecules with number density and phase-space density significantly higher than previously achieved. These improvements are enabled by three distinct changes to our recently-demonstrated scheme for radio-frequency magneto-optical trapping of SrF: modification of the slowing laser beam geometry, addition of an optical pumping laser, and incorporation of a compression stage to the magneto-optical trap. With these improvements, we observe a trapped sample of SrF molecules at density 2.5×105cm-3and phase-space density 6×10-14, each a factor of 4 greater than in previous work. Under different experimental conditions, we observe trapping of up to 104molecules, a factor of 5 greater than in previous work. Finally, by reducing the intensity of the applied trapping light, we observe molecular temperatures as low as 250 μK.
authors.affiliation: Department of Physics, Yale University, 217 Prospect St, New Haven, CT, 06511, USA.
authors.forename: Matthew H
authors.identifier: http://orcid.org/0000-0002-1291-7663
authors.initials: MH
authors.lastname: Steinecker
authors.affiliation: Department of Physics, Yale University, 217 Prospect St, New Haven, CT, 06511, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: McCarron
authors.affiliation: Department of Physics, Yale University, 217 Prospect St, New Haven, CT, 06511, USA.
authors.forename: Yuqi
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Physics, Yale University, 217 Prospect St, New Haven, CT, 06511, USA.
authors.forename: David
authors.initials: D
authors.lastname: DeMille
keywords: fluorides; laser cooling and trapping; low-temperature physics; polar molecules; strontium