Quantifying genuine tripartite entanglement by reshaping the state

Abstract

Although genuine multipartite entanglement (GME), as one quantum resource, is indispensable in quantum information processing, most of the existing measures cannot detect GME faithfully. In this paper we present a GME measure, namely, the minimum pairwise concurrence (MPC), by introducing pairwise entanglement, which characterizes the entanglement between two single-qubit subsystems of a multipartite system without tracing out the remaining qubit. The pairwise entanglement can be obtained by combining the entanglement of the reduced subsystem and the three-tangle. Compared with existing measures, the MPC measure outperforms the previous ones in many aspects. Due to its fine properties, it thus is believed that the MPC could be a good candidate for achieving potential quantum tasks and also could facilitate the understanding of GME.