The Decomposition of Werner and Isotropic States.

The well-known tough issue of the decomposition of separable Werner and Isotropic states is investigated in the Bloch representation. Thanks to the existence of SIC-POVM in arbitrary dimentional Hilbert space, we successively obtain the decomposition forms for any separable Werner states. And, by means of the relation between Werner state and Isotropic state, we can get as well the decomposition forms for separable Isotropic states. A geometrical interpretation of the decomposition feasibility in our scheme is given.