Abstract

Entangled states happen to be an essential tool for performing novel fundamental experiments, as well as for expanding our toolbox for quantum computation. While entanglement of two qubits is routine in the laboratory, entanglement of three photons with high quality has only recently been experimentally realized and used to experimentally demonstrate the extreme contradiction in so-called GHZ states between local realism and quantum mechanics. Yet in this case the quality of the entangled states still needs to be significantly improved in order to be useful for either tests of quantum mechanics or in quantum information schemes.

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