Study On Quantum Communication Theory Based On Non-maximal Entangled States

With the development of the technology, quantum information theory which is based on the quantum mechanics, becomes a new active field recently. In Chapters 1, 2 and 3, it discusses some fundamental elements of quantum informatics and quantum entanglement. In Chapter 4, it discusses the N-qubit general W state. With the concurrence, it demonstrates that the quantum state transmission could be accomplished by the non-maximal entangled states. Then it proposes a perfect transfer scheme with arbitrary particles and a scheme for preparing the N-qubit general W state. In Chapter 5, it proposes a scheme for coding and decoding in high-dimensional quantum systems, which is then applied to the non-maximal entangled systems. In Chapter 6, it concerns on the time departures that are resulted by the inaccurate-measure theory in Bell state preparing process and gives a scheme for applying them to quantum states transfer. In Chapter 7, the state transfer or the entanglement transmission between photons and atoms has been proposed. Some kinds of systems of photons and∧-type atoms are analyzed and the successful probabilities are obtained.