Experimental Generation And Application Of Multi-photon Entanglement States

We have developed a new type ultra-bright source of entangled photons based on spontaneous parametric down-conversion and a stable interferometer. On the basis of these new advances, in the thesis, we mainly discussed the experimental realization of various multi-photon entanglement. The main results are listed as follow:1. We have developed a ultra-bright four-photon entanglement source, about2000/s. With this four-photon entanglement, we have realized the quantum tele-portation of independent qubits over a97-kilometre one-link free-space channel. Besides being of fundamental interest in quantum mechanics, our results represent an important step towards a global quantum net work.2. We have realized the preparation of the seven-, eight-photon GHZ state. As a quantum resource, they will enable new experiments on, for example, quan-tum simulation, topological error correction and testing entanglement dynamies under decoherence.3. We report an experimental realisation of a three-qubit logical concatenated GHZ C-GHZ) state encoded by a six-qubit graph state. Such a C-GHZ state has better entanglement quantities under any noise-even white noise in principle-in comparison to normal GHZ state.4. We report an experimental generation of one basis vectors (|0)L) for five-bit quantum error correcting code (QECC).5We theoretically show that, for different error models that reducing the viola on of an inequality can improve the significance. And experimentally, we observe this phenomenon in a four-photon experiment, testing the Mermin and Ardehali inequality for different levels of noise. We believe that results on statis-tical confidence can give new insights in finding multiparticle entanglement test tools.