Multiqubit entanglement engineering via projective measurements

We present strategies to obtain different classes of three and four photon entangled symmetric states from a single experimental setup. The basic idea originates from the property of the symmetric Dicke state with two excitations to connect the two inequivalent types of genuine tripartite entanglement. We experimentally confirm the distinct types of entanglement of the observed states. We further propose an extension of the applied scheme that allows one to obtain different classes of four-photon entanglement by adding a fifth photon. The requirement of a single fifth photon is currently a technical challenge, and thus we consider the approach of using a strongly attenuated weak coherent beam instead.