Quantum optomechanics of a Bose-Einstein Antiferromagnet
  We investigate the cavity optomechanical properties of an antiferromagnetic Bose-Einstein con- densate, where the role of the mechanical element is played by spin-wave excitations. We show how this system can be described by a single rotor that can be prepared deep in the quantum regime under realizable experimental conditions. This system provides a bottom-up realization of dispersive rotational optomechanics, and opens the door to the direct observation of quantum spin fluctuations. 
H. Jing, D. S. Goldbaum, L. Buchmann, and P. Meystre
quant-ph cond-mat.quant-gas physics.atom-ph physics.optics