Preparation and Control for Periodic Quantum Echo of Atom Bit via Two-mode Light Field Intensity-dependent Coupling Multiphoton Channel
Preparation and Control for Periodic Quantum Echo of Atom Bit via Two-mode Light Field Intensity-dependent Coupling Multiphoton Channel
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DOI：
10.3788/gzxb20114012.1803
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发表时间：
2011
影响因子：
0.6
通讯作者：
周并举 Zhou Bing-ju;刘小娟 Liu Xiao-juan;刘明伟 Liu Ming-wei;王艳辉 Wang Yan-hui;彭朝晖 Peng Zhao-hui;姜春蕾 Jiang Chun-lei;刘一曼 Liu Yi-man
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文献类型：
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作者：
周并举 Zhou Bing-ju;刘小娟 Liu Xiao-juan;刘明伟 Liu Ming-wei;王艳辉 Wang Yan-hui;彭朝晖 Peng Zhao-hui;姜春蕾 Jiang Chun-lei;刘一曼 Liu Yi-man
在行波近似下，利用全量子理论，通过依赖强度耦合多光子通道，研究了原子比特与双模相干光场相互作用中周期性量子回波的产生和控制，讨论了双模相干光场平均光子数的分布形式和分布范围对原子比特保真度演化的影响，和原子跃迁时吸收（发射）的光子数k，得到了制备和控制原子比特周期性量子回波的系统参数.根据纠缠理论，分析了原子比特保真度与原子约化熵的关系.结果表明，原子比特保持了良好的相干性和保真度，当k=1时，通过调节光场的平均光子数的对称或非对称分布及其值在一定范围内，双光子过程将产生周期性的量子回波，对于k≥2的多光子过程，原子位总是与两个原子处于最大纠缠状态通过引入一个模相干光场，使原子比特处于部分畸变状态，而不产生周期量子回波，证明了周期量子回波产生的物理本质是周期性的在原子位和光场之间解开纠缠。
In the rotating-wave approximation,the produce and control for periodic quantum echo of atom bit interacting with a two-mode coherent light field is investigated via intensity-dependent coupling multiphoton channel by means of the full quantum theory.The effects on the evolution of the fidelity of atom bit for both the distribution form and distribution range of the average photon number of the two-mode coherent light field,and the photon number k of absorbed(emitted) as the atoms transition are discussed by numerical calculations,respectively.The system parameter of preparation and control for periodic quantum echo of atomic bits are obtained.According to the entanglement theory,the relation of the fidelity of atom bit with atomic reduced entropy is analyzed.The results show that atom bitkeeps good coherence and fidelity,and will produce periodic quantum echo for the two photon process as k=1,by regulation average photon number of the light fields being symmetrical or asymmetrical distribution and its value in a certain range.For k≥2 multiphoton process,the atom bit is always in a maximally entangled with the two-mode coherent light field so that the atom bit is in a state of partial distortion without periodic quantum echo.It is shown that the physical nature of the periodic quantum echo produce is periodic disentangled between the atom bit and the light field.