@article{12092,
  author = {Shiqian Ding and Yewei Wu and Ian Finneran and Justin Burau and Jun Ye},
  title = {Sub-Doppler Cooling and Compressed Trapping of YO Molecules at uK Temperatures},
  abstract = {Complex molecular structure demands customized solutions to laser cooling by extending its general set of principles and practices. Compared with other laser-cooled molecules, yttrium monoxide (YO) exhibits a large electron-nucleus interaction, resulting in a dominant hyperfine interaction over the electron spin-rotation coupling. The YO ground state is thus comprised of two manifolds of closely spaced states, with one of them possessing a negligible Landé g factor. This unique energy level structure favors dual-frequency dc magneto-optical trapping (MOT) and gray molasses cooling (GMC). We report exceptionally robust cooling of YO at 4μK
over a wide range of laser intensity, detunings (one- and two-photon), and magnetic field. The magnetic insensitivity enables the spatial compression of the molecular cloud by alternating GMC and MOT under the continuous operation of the quadrupole magnetic field. A combination of these techniques produces a laser-cooled molecular sample with the highest phase space density in free space.},
  year = {2020},
  journal = {Physical Review X},
  volume = {10},
  chapter = {021049},
  pages = {021049},
  month = {2020-06},
  url = {https://link.aps.org/doi/10.1103/PhysRevX.10.021049},
  doi = {10.1103/PhysRevX.10.021049},
}