Remarks on Lewenstein-Sanpera Decomposition
  We discuss in this letter Lewenstein-Sanpera (L-S) decomposition for a specific Werner state. Compared with the optimal case, we propose a quasi-optimal one which in the view of concurrence leads to the same entanglement measure for the entangled mixed state discussed. We think that in order to obtain entanglement of given state the optimal L-S decomposition is not necessary. 
Mingjun Shi, Jiangfeng Du