  Entanglement as a vital resource for information processing can be described
by special properties of the quantum state.
  Using the well-known Weyl basis we propose a new Bloch decomposition of the
quantum state and study its separability problem.
  This decomposition enables us to find an alternative characterization of the
separability based on the correlation matrix.
  We shaw that the criterion is effective in detecting entanglement for the
isotropic states, Bell-diagonal states and some PPT entangled states.
  We also use the Weyl operators to construct an detecting operator for quantum
teleportation.
