Localization of Relative-Position of Two Atoms Induced by Spontaneous   Emission
  We revisit the back-action of emitted photons on the motion of the relative position of two cold atoms. We show that photon recoil resulting from the spontaneous emission can induce the localization of the relative position of the two atoms through the entanglement between the spatial motion of individual atoms and their emitted photons. The result provides a more realistic model for the analysis of the environment-induced localization of a macroscopic object. 
L.Zheng, C.Li, Y.Li, C.P.Sun