Probabilistic and controlled teleportation of tripartite state in a general form and its quantum networks

We discuss a scheme for probabilistic and controlled teleportation of an unknown arbitrary three-particle state by constructing a peculiar non-maximally entangled state as a controlled quantum channel，which is teleported between two sides with the help of the auxiliary particle and the cooperation of the third side (Charlie) as a supervisor. In comparison with some existing schemes, on the receiver's side it is easy to have the sender's state through operating two uniform unitary transformations in turn. In addition, we also give an efficient quantum network for implementing the new scheme by means of some primitive operations.     

A new approach to obtaining positive-definite Wigner operator for two entangled particles with different masses

Based on our previously proposed Wigner operator in entangled form,we introduce the generalized Wigner operator for two entangled particles with different masses,which is expected to be positive-definite.This approach is able to convert the generalized Wigner operator into a pure state so that the positivity can be ensured.The technique of integration within an ordered product of operators is used in the discussion.