Lower bound on concurrence for arbitrary-dimensional tripartite quantum   systems
  In this paper, we study the concurrence of arbitrary dimensional tripartite quantum systems. An explicit operational lower bound of concurrence is obtained in terms of the concurrence of sub-states. A given example show that our lower bound may improve the well known existing lower bounds of concurrence. The significance of our result is to get a lower bound when we study the concurrence of arbitrary dimensional multipartite quantum systems. 
Wei Chen, Shao-Ming Fei and Zhu-Jun Zheng
quant-ph math-ph math.MP