N identical particles and one particle to entangle them all
Bruno Bellomo, Rosario Lo Franco, Giuseppe Compagno · Physical Review A · 2017
In quantum information, $W$ states are a central class of multipartite entangled states because of their robustness against noise and their use in many quantum processes. Their generation, however, remains a demanding task whose difficulty increases with the number of particles. We report a simple scalable conceptual scheme where a single particle in an ancilla mode works as an entanglement catalyst of the $W$ state for other $N$ separated identical particles. A crucial aspect of the scheme, which exploits basically spatial indistinguishability, is its universality, being applicable without essential changes to both bosons and fermions. Our proposal represents a paradigm within the experimental preparation of many-particle entanglement based on quantum indistinguishability.