Direct laser cooling of calcium monohydride molecules

Abstract

We demonstrate optical cycling and sub-Doppler laser cooling of a cryogenic buffer-gas beam of calcium monohydride (CaH) molecules. We measure vibrational branching ratios for laser cooling transitions for both excited electronic states A and B. We measure further that repeated photon scattering via the $A\leftarrow X$ transition is achievable at a rate of $\sim$ $1.6\times 10^6$ photons/s and demonstrate the interaction-time limited scattering of $\sim$ $200$ photons by repumping the largest vibrational decay channel. We also demonstrate the ability to sub-Doppler cool a molecular beam of CaH through the magnetically assisted Sisyphus effect. Using a standing wave of light, we lower the molecular beam's transverse temperature from $12.2(1.2)$ mK to $5.7(1.1)$ mK. We compare these results to sub-Doppler forces modeled using optical Bloch equations and Monte Carlo simulations of the molecular beam trajectories. This work establishes a clear pathway for creating a magneto-optical trap (MOT) of CaH molecules. Such a MOT could serve as a starting point for production of ultracold hydrogen gas via dissociation of a trapped CaH cloud.

arXiv comment11 pages, 4 figures, 3 tables

References in corpus (39)

• Many-Body Physics with Ultracold Gases
• Search for New Physics with Atoms and Molecules
• Laser cooling of a diatomic molecule
• Bose-Einstein Condensation of Atomic Hydrogen
• Magneto-optical trapping of a diatomic molecule
• Resolving the gravitational redshift within a millimeter atomic sample
• Improved Measurement of the Hydrogen 1S - 2S Transition Frequency
• The Buffer Gas Beam: An Intense, Cold, and Slow Source for Atoms and Molecules
• Molecules cooled below the Doppler limit
• Quantum simulation and computing with Rydberg-interacting qubits
• Sisyphus Laser Cooling of a Polyatomic Molecule
• Radio Frequency Magneto-Optical Trapping of CaF with High Density
• Laser Cooling of Optically Trapped Molecules
• 3-D Magneto-Optical Trap of Yttrium Monoxide
• Ultracold molecules for measuring the electron's electric dipole moment
• Many-body dynamics of dipolar molecules in an optical lattice
• Sisyphus Cooling of Electrically Trapped Polyatomic Molecules
• Magneto-Optical Trap for Polar Molecules
• Magneto-Optical Trapping and Sub-Doppler Cooling of a Polyatomic Molecule
• Direct Laser Cooling of a Symmetric Top Molecule
• Sub-millikelvin dipolar molecules in a radio-frequency magneto-optical trap
• Ultracold polar molecules as qudits
• Laser-Cooled Polyatomic Molecules for Improved Electron Electric Dipole Moment Searches
• Ultracold molecules for quantum simulation: rotational coherences in CaF and RbCs
• Second-Scale Nuclear Spin Coherence Time of Trapped Ultracold ${}^{23}$Na${}^{40}$K Molecules
• Sub-Doppler Cooling and Compressed Trapping of YO Molecules at $\mu$K Temperatures
• Laser cooling of molecules
• A Bright, Slow Cryogenic Molecular Beam Source for Free Radicals
• Deep laser cooling and efficient magnetic compression of molecules
• Cold and Slow Molecular Beam
• Measurement of the $2$S${}_{1/2}-8$D${}_{5/2}$ transition in hydrogen
• Three-dimensional Doppler, polarization-gradient, and magneto-optical forces for atoms and molecules with dark states
• Spectroscopy of atomic hydrogen. How is the Rydberg constant determined?
• Ultracold hydrogen and deuterium production via Doppler-cooled Feshbach molecules
• Determination of CaOH and CaOCH${}_3$ vibrational branching ratios for direct laser cooling and trapping
• Optical cycling, radiative deflection and laser cooling of barium monohydride (BaH)
• BaH molecular spectroscopy with relevance to laser cooling
• Laser cooling and magneto-optical trapping of molecules analyzed using optical Bloch equations and the Fokker-Planck-Kramers equation
• Large molasses-like cooling forces for molecules using polychromatic optical fields: A theoretical description

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