操作腔外原子比特控制腔内多光子过程中原子比特熵压缩性质  

Controlling entropy squeezing properties of atomic qubit inside the cavity via multiphoton process by manipulating the other atomic qubit outside the cavity

作　　者：罗岸[1] 刘小娟[1] 

机构地区：[1]湖南科技大学物理与电子科学学院,湖南湘潭411201

出　　处：《湖南科技大学学报（自然科学版）》2016年第1期112-117,共6页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：国家自然科学基金资助项目(11104068;11405052)

摘　　要：考虑初始处于Bell态的两原子比特，将其中一个注入真空态腔中发生多光子共振相互作用情况．运用量子信息熵理论，研究对腔外原子比特施逻辑门操作及基态测量前后，腔内原子比特的熵压缩性质．结果表明，操作腔外原子比特前，腔内原子比特不产生熵压缩现象；对腔外原子比特施Hadamard（H）门和H类门操作后，在k=3光子过程中，腔内原予比特产生周期为π/√3！墒压缩现象，可制备最佳熵压缩态；在k〉3的多光子过程中，随着光子数增加，熵压缩因子E（Sx）产生高频振荡，一般熵压缩频繁出现，最佳熵压缩产生次数明显增加，有利于噪声环境下量子通信和量子计算的实验实现．Two identical two -level atoms that initially in Bell state were considered. One of the two atoms was injected into a single mode vacuum cavity to produce multiphoton resonance while the other was outside the microwave cavity. Using information entropy squeezing theory, the information entropy squeezing properties was investigated, that of atomic qubit inside the cavity before and after performing logic gate operations on the other atomic qubit outside the cavity and measure its ground state. It is shown that atomic qubit inside the cavity has no entropy squeezing phenomenon before manipulating atomic qubit outside the cavity. In the case of photon number k = 3, after Hadamard （H） and H - like logic gate manipulations on the atom bit outside the cavity, the entropy squeezing phenomenon with periodπ/√3! can be generated and the optimal entropy squeezing state can be prepared of atomic qubit inside the cavity. In the case of photon number k 〉 3, with the increasing photon number, high -frequency oscillation emerges in the entropy squeezing factor E（Sx ）, and the times of the optimal entropy squeezing of the atomic qubit inside the cavity increase significantly. The multiphoton process may be helpful to the experimental implementation of quantum communication and quantum computing in a noisy environment.

关 键 词：多光子过程 熵压缩 逻辑门操作 基态测量 

分 类 号：O431.2[机械工程—光学工程]