Abstract

We consider time-dependent evolution of the field-free molecular alignment and orientation for different rotational quantum states, induced by a single- and dual-color femtosecond laser pulses. We show that, compared to the evolutions of overall molecular alignment and orientation averaged by all rotational states, evolutions of each quantum state’s contribution present more complex temporal structure and provide richer dynamical evolving process of the molecules. Furthermore, we investigate the variation of the maximal degrees of the molecular alignment and orientation in different rotational quantum states. The results show that maximal degrees of both the molecular alignment and anti-alignment have the same change trend with the rotational state distribution, while for the molecular orientation consistency only exists in the variation of the difference between the maximal values of the positive and negative orientation. Correlation analysis shows it is independent of the molecular rotational temperature.

Graphic Abstract

The maximal degrees of the molecular alignment and orientation show different evolution behaviors with the rotational state distribution

中文翻译：

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无场分子排列和取向中旋转量子态的演化

摘要

我们考虑了由单色和双色飞秒激光脉冲引起的不同旋转量子态的无场分子排列和取向的时间依赖性演变。我们表明，与所有旋转状态平均的整体分子排列和取向的演变相比，每个量子态贡献的演变呈现出更复杂的时间结构，并提供更丰富的分子动力学演变过程。此外，我们研究了不同旋转量子态下分子排列和取向的最大程度的变化。结果表明，分子排列和反排列的最大程度与旋转状态分布具有相同的变化趋势，而分子取向一致性只存在于正负取向最大值之差的变化中。相关分析表明它与分子旋转温度无关。

图形摘要

分子排列和取向的最大程度随着旋转状态分布表现出不同的演化行为