原子-二聚物分子转化系统在受激拉曼绝热过程中的绝热保真度

从原子-二聚物分子转化系统的非U（1）对称性出发，将保真度的定义推广到了非线性系统.并利用绝热保真度定量地研究了原子-二聚物分子转化系统在受激拉曼绝热过程中的动力学和绝热性.研究发现，这个系统的相干布居俘获态——暗态的绝热保真度作为绝热参量的函数以幂律关系趋于1.这个函数关系与线性系统的绝热参量和绝热保真度的幂律关系非常相似，但该系统的幂指数要远小于线性系统的幂指数.此外，还进一步讨论了如何通过优化受激拉曼绝热过程的外部参量得到更高的绝热保真度，从而优化系统的绝热性，提高原子-分子转化效率. 关键词： 原子-二聚物分子转化系统 暗态 受激拉曼绝热过程 绝热保真度

Adiabatic fidelity for atom-dimer conversion system in stimulated Raman adiabatic passage

From the non-U（1） invariance of the atom-dimer conversion system, we generalized the definition of fidelity to this nonlinear system. By making use of the adiabatic fidelity, we investigated the dynamics and adiabaticity of the atom-dimer conversion system in a stimulated Raman adiabatic passage （STIRAP）. We found that the adiabatic fidelity for the coherent population trapping state or dark state, as the function of the adiabatic parameter, approaches to unity following a power law. The power exponent, however, is much smaller than that predicted by the linear adiabatic theorem. We further discuss how to achieve higher adiabatic fidelity for the dark state through optimizing the external parameters of STIRAP and hence to optimize the adiabaticity of the system and obtain high conversion efficiency.