Distillation of genuine mixed state for quantum communications
  We present a practical entanglement distillation protocol (EDP) with linear optics for a genuine mixed state. Each components of the genuine mixed state is a pure less-entangled state.   After successfully performing this EDP, we can obtain a high quality entangled mixed state. Our EDP can work for both ideal entanglement sources and current available spontaneous parametric down-conversion (SPDC) sources, which makes it feasible in current experimental technology. Moreover, by using the SPDC source, we can obtain a higher fidelity. This protocol can also be used to distill the multi-partite entangled systems. All the features make it practical and useful in current quantum communications. 
Yu-Bo Sheng, Lan Zhou, Xing-Fu Wang
quant-ph