A characterization of N-partite quantum states, based on K-way (2≤K≤N) negativities, is proposed. For an N-partite system the fraction of K-way negativity (2≤K≤N), contributing to global negativity, is obtained. The entanglement measures for a given state ρ are identified as the fractional K-way negativities of the corresponding canonical state. Contributions to K-way negativity from different parts of the composite system are determined.
© 2007 Optical Society of AmericaPDF Article