非Lamb-Dicke近似下制备囚禁冷离子的振动相干态

根据非Lamb-Dicke近似下激光-离子相互作用动力学规律，讨论了如何利用一系列的激光脉冲来驱动冷离子，从而从运动基态出发获得一系列振动数态的宏观叠加态.具体研究了这些叠加态的Q函数、Wigner函数和它们的非经典特性，如压缩和反群聚效应等.结果表明，合适地调节各个所用激光的脉冲长度，所产生的叠加态能很好地逼近熟知的振动相干态. 关键词： Lamb-Dicke近似 叠加态 相干态 非经典特性

Generations of coherent states of single trapped cold ion beyond the Lamb-Dicke limit

Based on the quantum dynamics of laser-ion interaction beyond the Lamb-Dicke limit, we discuss how to superpose a series of vibrational number states from motional ground state by sequentially applying laser beams. The Q function, Wigner distribution function, and the nonclassical properties such as squeezing effect and anti-bunching effect of the generated superposition states are investigated in detail by numerical method. It is shown that, by controlling the durations of the applied laser pulses, these .quantum states could well approach to the well-known coherent states.