摘要
通过使用含时量子波包方法，对HF分子该类型的布居转移动力学进行了研究．提出双∑型激光控制方案，用于控制布居从1u=16）能级向（v=0〉能级进行转移，该方案的第一步是将布居从｜u=16〉经过中间能级｜v=11〉向1v=7）转移，第二步是将布居从｜v=7）经过中间能级lv=3〉向｜v=0）转移．在每一个步骤中，三个振动能级在两束重叠的激光脉冲作用下形成一个∑型的布居转移路径．通过优化激光的强度、频率和延迟时间，得到了最大的布居转移效率．计算并比较了正序脉冲和反序脉冲两种情况，在这两种情况下，布居都可以超过90％从｜v=16〉能级向｜v=0〉能级进行转移．
The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-wave-packet method, the population transfer dynamics is investigated theoretically for the HF molecule. A double-E-type laser scheme is proposed to transfer the population from the ｜v=16〉 level to the ground vibrational level ｜v=0〉 on the ground electronic state. The scheme consists of two steps： The first step is to transfer the population from ｜v=16〉 to ｜v=7〉 via an intermediate level ｜v=11〉, and the second one is to transfer the population from ｜v=7〉 to ｜v=0〉 via ｜v=3〉. In each step, three vibrational levels form a E-type population transfer path under the action of two temporally overlapped laser pulses. The maximal population-transfer efficiency is obtained by optimizing the laser inten- sities, frequencies, and relative delays. Cases for the pulses in intuitive and counterintuitive sequences are both calculated and compared. It is found that for both cases the population can be efficiently （over 90%） transferred from the ｜v=-16〉 level to the ｜v=0〉 level.
基金
Li-hang Li thanks Dr. Yin Huang for assistance. The project is supported by the Specialized Research Fund for the Doctoral Program of Higher Education （No.20130041120053）, SRF for ROCS, SEM, the Sci- ence and Technology Research Funds of the Depart- ment of Education of Liaoning Province （L2013014）, the National Magnetic Confinement Fusion Science Pro- gram （No.2013GB109005）, the Fundamental Research Funds for the Central Universities （DUT12RC（3）60）, and the NationM Natural Science Foundation of China （No.21473018, No.10974024, and No.11274056）.
