The Entropy Squeezing Of The Field And The Nonlocality Of Quantum

Quantum optics is a subject on studying quantum statistical and analyzing the quantum character of light interacting with matter. It has been proved by experiment that quantum states of cavity field can exhibit three non-classical features, i.e. photo antibunching effect sub-Poissonian statistics distribution and squeezing states. In the squeezing states, because the quantum fluctuation of its one quadrature is below that of the standard level, the squeezing states have comprehensive applications in optical communication systems, and so on. In many literatures, people commonly begin with the Heisenberg uncertainty principle, verdict that the light field is squeezing while the quantum fluctuation of its orthogonal variant below that of the vacuum's. Does there exist a more sensitive measure to judge the squeezing effect of the light field, we try to do it by the information entropy. In this article, we built the concept of the information entropy, and starting on the entropy uncertainty relations, comparing with the Heisenberg uncertainty relations, studied the entropy squeezing effect of the superposition of the vacuum state and the Fock states.Quantum information which based on the quantum mechanics is the result of combining quantum mechanics and information science. It mainly includes quantum cryptography quantum communication quantum computer, and so on. In recent years, it has been made great breakthrough at the aspect of theory and experiment. For example quantum cryptography is a code teleportation scheme which combining cryptography with quantum mechanics and based on the quantum nonlocality. But the debating on the quantum mechanics' essence problem is never stopping when it was born. This thesis studied the quantum nonlocality which is one of the quantum mechanics' Characters. Firstly wesummarized the EPR paradox, and Bell inequality theorem as well as its generalized Bell type inequalities. Then using the CHSH inequality we studied the quantum nonlocality of two spin-1/2 's entangled quantum states.