Dynamics of molecular alignment steered by a few-cycle terahertz laser pulse  

作　　者：Qi-Yuan Cheng Yu-Zhi Song Deng-Wang Li Zhi-Ping Liu Qing-Tian Meng 程起元;宋玉志;李登旺;刘治平;孟庆田(Medical Engineering Department,Shandong Provincial Hospital Affiliated to Shandong First Medical University,Jinan 250021,China;School of Physics and Electronics,Shandong Normal University,Jinan 250358,China;Shandong Laibo Biotechnology Co.,Ltd.,Jinan 250101,China;School of Control Science and Engineering,Shandong University,Jinan 250061,China)

机构地区：[1]Medical Engineering Department,Shandong Provincial Hospital Affiliated to Shandong First Medical University,Jinan 250021,China [2]School of Physics and Electronics,Shandong Normal University,Jinan 250358,China [3]Shandong Laibo Biotechnology Co.,Ltd.,Jinan 250101,China [4]School of Control Science and Engineering,Shandong University,Jinan 250061,China

出　　处：《Chinese Physics B》2022年第10期377-383,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.12274265 and 11874241);the Taishan Scholar Project of Shandong Province,China。

摘　　要：The field-free alignment of molecule Cl CN is investigated by using a terahertz few-cycle pulse(THz FCP)based on the time-dependent density matrix theory.It is shown that a high degree of molecular alignment can be obtained by changing the matching number of the THz FCPs in the adiabatic regime and the non-adiabatic regime.The matching number can affect both the maximum value of the alignment and the time at which it is achieved.It is also found that a higher degree of alignment can be achieved by using the THz FCP at lower intensity and there exists an optimal threshold of molecular alignment with the increase of the field amplitude.Also found is the frequency sensitive region in which the degree of maximum alignment can be enhanced greatly by modulating the center frequencies of different THz FCPs.The investigation demonstrates that comparing with a THz single-cycle pulse,a better result of the field-free alignment can be created by a THz FCP at a constant rotational temperature of molecule.

关 键 词：molecular alignment few-cycle terahertz pulse density matrix theory 

分 类 号：O441.4[理学—电磁学] O561[理学—物理]