飞秒激光控制的分子量子动力学研究:(Ⅰ)三维二能级系统

Femtosecond laser pulse control of multidimensional vibrational dynamics: (Ⅰ) the three vibrational mode two electronic state system

结合MCDTDH方法和优化控制理论,以吡嗪分子为例,模拟了在给定不同的目标态下具有3个振动模两个电子态的分子系统的量子动力学过程.以电子激发态作为目标态,优化激光场为一个楔形脉冲,它所激发的电子波函数在两个调制模空间中振荡最后达到平衡位置,并有较高的目标态产生率.发现目标态的选择强烈地影响波函数随时间的演变情况,若目标态在各个模的平衡位置,在优化激光场的作用下,电子波函数被直接激发到其平衡位置;若目标态不在振动模的平衡位形,其电子波函数经过强烈的振荡以达到平衡态.

With the combination of optimal control theory and MCTDH method, given a certain target state, the quantum dynamics of pyrazine molecule system, which has been modeled as two electronic states and three vibrational modes, have been simulated. With the electronic excited state as the target state, what we get of the optimal pulse has a form of cuniform, which excites the wave-packet to the electronic excited state. In the tuning mode coordinate, the reduced probabilities oscillate strongly to obtain a high yield of target state. Given different target states, the evolution of probability density also demonstrates different behaviors. With the target state at the vibrational ground state of each coordinate in electronic excited state, the wave-packet is directly excited to their equilibrium positions. With the target state at the shifted vibrational state, the wave-packet oscillates strongly to reach its target state.