Magnetically-controlled velocity selection in a cold atom sample using   stimulated Raman transitions
  We observe velocity-selective two-photon resonances in a cold atom cloud in the presence of a magnetic field. We use these resonances to demonstrate a simple magnetometer with sub-mG resolution. The technique is particularly useful for zeroing the magnetic field and does not require any additional laser frequencies than are already used for standard magneto-optical traps. We verify the effects using Faraday rotation spectroscopy. 
Matthew L. Terraciano, Spencer E. Olson, Mark Bashkansky, Zachary   Dutton, Fredrik K. Fatemi