Operational determination of multiqubit entanglement classes via tuning of local operations

Phys Rev Lett. 2009 Feb 6;102(5):053601. doi: 10.1103/PhysRevLett.102.053601. Epub 2009 Feb 3.

Abstract

We present a physical setup with which it is possible to produce arbitrary symmetric long-lived multiqubit entangled states in the internal ground levels of photon emitters, including the paradigmatic Greenberger-Horne-Zeilinger and W states. In the case of three emitters, where each tripartite entangled state belongs to one of two well-defined entanglement classes, we prove a one-to-one correspondence between well-defined sets of experimental parameters, i.e., locally tunable polarizer orientations, and multiqubit entanglement classes inside the symmetric subspace.