Dynamics of quantum discord in the purification process
  We investigate the dynamics of quantum discord during the purification process. In the case of Werner states, it is shown that quantum discord is increased after a round of purification protocol. Furthermore, quantum mutual information and classical correlation is also increased during this process.Wealso give an analytic expression for a class of higher dimensional states which have additive quantum discord. 
Wei Song, Lin Chen, Ming Yang, and Zhuo-Liang Cao
quant-ph