@article{1069,
  author = {X. Xu and T. Loftus and J. Dunn and Chris Greene and John Hall and Alan Gallagher and Jun Ye},
  title = {Single-Stage Sub-Doppler Cooling of Alkaline Earth Atoms},
  abstract = {We report the first experimental study of sub-Doppler cooling in alkaline earth atoms (87Sr) enabled
by the presence of nuclear spin-originated magnetic degeneracy in the atomic ground state. Sub-Doppler
cooling in a (\sigma+) - (\sigma-) configuration is achieved despite the presence of multiple, closely spaced excited
states. This surprising result is confirmed by an expanded multilevel theory of the radiative cooling
force. Detailed investigations of system performance have shed new insights into ((\sigma+) - (\sigma-)) cooling
dynamics and will likely play an important role in the future development of neutral atom-based
optical frequency standards.},
  year = {2003},
  journal = {Physical Review Letters},
  volume = {90},
  month = {Jan-05-2003},
  issn = {0031-9007},
  doi = {10.1103/PhysRevLett.90.193002},
}