Reporter: Songbin Zhang, Shaanxi Normal University, School of physics and information technology, song-bin.zhang@snnu.edu.cn

Introduction:

Professor and doctoral supervisor of Shaanxi Normal University, selected into the national innovative talent youth project in 2016, member of the National Professional Committee of computational atomic and molecular physics, and joint youth Editorial Committee of China Physics express / China Physics B / Journal of physics / physics. He graduated from Sichuan University with a bachelor's degree in physics in 2007 and received a doctor's degree in science from the University of science and technology of China in 2011; From 2011 to 2015, he successively engaged in post doctoral research in Texas A & M University, German Mapu Institute and free electron laser science center, and joined the school of physics of Shaanxi Normal University at the end of 2015. The main research field is theoretical atomic and molecular ultrafast photophysics. More in-depth theoretical research work has been carried out in atomic and molecular structure, electron atomic and molecular collision, heavy ion collision and the interaction between extreme light sources such as Ultrafast Intense Laser Field / attosecond pulse / X-ray and atoms and molecules. It has been published in the international mainstream academic journals PRL / A / R, JPCL, NJP in this field, JCP and others have published more than 50 physics research papers and are reviewers of PRL / A / B / E / M, JPCL and other journals. Relevant work has been supported by key projects, general projects, youth projects of NSFC and special projects of science challenge program of national defense science and industry administration.

Summary:

For diatomic molecules, when the component Ω of electron angular momentum in the molecular axis is not zero, it will be inherently coupled with rotational angular momentum R, that is, the so-called electron rotational coupling (R-Ω coupling. Under the action of weak light field, since the molecular rotational mass is much greater than the electron mass, and the change of angular momentum introduced by the electron transition process is very small, the R-Ω coupling effect is naturally small and can be effectively ignored. However, under the action of strong VUV / XFEL, Rabi oscillation can occur between electronic states, and the change introduced by the small angular momentum accumulated many times may change Molecular rotational dynamics process. Therefore, when it is necessary to explain and simulate observable measurements directly related to rotational dynamics, such as molecular orientation, angular distribution of photodissociated fragments, R-Ω coupling effect must be fully considered in the physical model. We reconstructed the physical theory including R-Ω coupling effect and studied the bisection of r-Ω coupling effect under strong VUV in detail The effect of sub direct photoexcitation and angular distribution of photolysis dynamics [1,2], the influence of R-Ω coupling effect on optical absorption spectrum and resonance Auger spectrum under strong XFEL [3], and the R-Ω coupling effect is used to effectively control the molecular dynamics process in combination with UV pump detection technology [4]. The relevant research results not only improve the existing theoretical model of light field molecular interaction, but also provide the possibility of fine regulation of molecular dynamics process by using fine physical effects.

References:

1. Y. R. Liu, Y. Wu, J. G. Wang, O. Vendrell, V. Kimberg, and S. B. Zhang*, Phys. Rev. A 102, 033114 (2020).

2. Y. R. Liu, Y. Wu, J. G. Wang, O. Vendrell, V. Kimberg, and S. B. Zhang*, Phys. Rev. Research 2, 043348 (2020).

3. Y. P. Zhu, Y. R. Liu, X. Zhao, V. Kimberg, and S. B. Zhang*, Chin. Phys. Lett. 38, 053201 (2021). (Editor’s suggestion)

4. Y. R. Liu, V. Kimberg, Y. Wu, J. G. Wang, O. Vendrell, and S. B. Zhang*,  J. Phys. Chem. Lett. 12, 5534 (2021).

Report time: 9:00-12:00, July 23, 2021 (Friday)

Report Location: conference room 504, life science building