Tripartite State Characterization via Activated Bipartite Entanglement

Abstract

We propose a way to identify and classify genuine tripartite entanglement in pure states of three-qubit systems via the Activated Bipartite Entanglement (ABE). We show that for pure states pertaining to one of the two inequivalent classes of genuine tripatite entanglement, for which the GHZ and the W states are the notorious representatives, the ABE is always greater than zero, while for separable tripartite pure states or bipartite entanglement between two parts of three-qubit pure states it is always null. In addition we present a experimental proposal by using liner optical circuits and degrees of freedom of a single photon to verify the characterization via distributed entanglement. The circuit simulation showed an excellent accordance with theoretical prediction for a wide classes of GHZ states.