Dissipative preparation of entangled states between two spatially   separated nitrogen-vacancy centers
  We present a novel scheme for the generation of entangled states of two spatially separated nitrogen-vacancy (NV) centers with two whispering-gallery-mode (WGM) microresonators, which are coupled either by an optical fiber-taper waveguide, or by the evanescent fields of the WGM. We show that, the steady state of the two NV centers can be steered into a singlet-like state through a dissipative quantum dynamical process, where the cavity decay plays a positive role and can help drive the system to the target state. The protocol may open up promising perspectives for quantum communications and computations with this solid-state cavity quantum electrodynamic system. 
Peng-Bo Li, Shao-Yan Gao, Hong-Rong Li, Sheng-Li Ma, and Fu-Li Li
quant-ph