A theoretical scheme used for controlling molecular orientation with few-cycle terahertz pulse is proposed, taking the NaI molecule as an example. The time-dependent quantum wave packet theory method is used to accurately solve the time-dependent Schrödinger equation including rotational degrees of freedom and vibrational degrees of freedom. By optimizing the parameters of few-cycle terahertz pulse, the maximal orientation, 0.824, is achieved. By modualting the carrier envelope phase (CEP) of few-cycle terahertz pulse, the enhancement and suppression of molecular orientation can be effectively controlled. Moreover, the molecular orientation degrees are dependent on the center frequency and the intensity of electric field of the few-cycle terahertz pulse. The numerical computation result shows that the orientation of the NaI molecule can be effectively steered by using our scheme.

以NaI分子为例，提出了一种利用少周期太赫兹脉冲控制分子取向的理论方案。时变量子波包理论方法用于精确求解时变薛定ding方程，包括旋转自由度和振动自由度。通过优化几个周期的太赫兹脉冲的参数，可以达到最大方向0.824。通过改变几个周期的太赫兹脉冲的载流子包络相（CEP），可以有效地控制分子取向的增强和抑制。而且，分子取向度取决于几周期太赫兹脉冲的中心频率和电场强度。