2021-02-26

Chinese researchers have discovered the quantum interference phenomenon of spin-orbit partial waves in elementary chemical reactions

By yqqlm yqqlm

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Since Uhlenbeck and Gudschmidt discovered the phenomenon of electron spin in 1925, people It is found that the coupling of electron spin and orbital angular momentum in systems such as atoms and molecules can lead to many interesting phenomena, such as the splitting of atomic energy levels, magnetocrystalline anisotropy, and the quantum Hall effect in semiconductors.

It is reported that the coupling of electron spin and orbital angular momentum will affect the collision process of atoms and molecules. In a chemical reaction, the electron spin-orbit coupling will cause the splitting of the scattering partial waves of the reaction, which may make the partial waves have some fine structures.

The research on electron spin and orbital angular momentum has long faced an unknown and extremely challenging question: whether and how electron spin-orbit coupling can affect the dynamics of chemical reactions?

In order to solve this problem, the researchers combined experiment and theory on the influence of electron spin and orbital angular momentum in the reaction of fluorine atom and hydrogen molecule F+HD->HF+D Research:

Chinese researchers have discovered the quantum interference phenomenon of spin-orbit partial waves in elementary chemical reactions

Caption: D atom product ion Speed ​​image, the left side of the figure shows a “horseshoe”-shaped structure in the forward scattering direction.

·In terms of experiment, by combining the cross molecular beam method, time slice ion velocity imaging technology and near-threshold ionization technology, the high-resolution experimental measurement is used to obtain the differential scattering cross section of the product rotation quantum state resolution. And a unique horseshoe-shaped structure was observed in the forward scattering direction of the differential scattering cross section;

·In terms of theory, a quantum dynamics theory simulation method considering the electronic angular momentum effect was developed. The dynamic structure is explained.

Finally, the theory shows that this dynamic structure is caused by the quantum interference of the resonant partial wave of the spin-orbit splitting with positive and negative parity. It also shows that the spin-orbit interaction can effectively Affect the kinetic process of chemical reactions.

The results will be published in the journal Science on February 26, 2021. Dr. Wentao Chen from the Hefei National Research Center for Physical Sciences at the University of Science and Technology of China is the first author of this paper.

This work was supported by the National Key Research and Development Program, the National Natural Science Foundation of China, and the Strategic Leading Science and Technology Project (Category B) of the Chinese Academy of Sciences.