A paradigm for entanglement and information swapping of two qubits
  Based on a general unitary operation of two-qubit system, we investigate the dynamics of entanglement, entropy and purity. Distinctive features in the different initial states settings of an interacting bipartite system are explored. The striking effects of initial product states on entanglement shows that zeros entanglement can be obtained during the development of the interaction. 
Nasser Metwally and Mahmoud Abdel-Aty