The vibrational and hyperfine spectroscopy toward laser cooling 87Sr35Cl

Huagang Xiao; Jiangnan Wang; Ruijie Zhang; Na Shan; Tao Gao

doi:10.1016/j.saa.2022.121679

The vibrational and hyperfine spectroscopy toward laser cooling ⁸⁷Sr³⁵Cl

Spectrochim Acta A Mol Biomol Spectrosc. 2022 Dec 5:282:121679. doi: 10.1016/j.saa.2022.121679. Epub 2022 Jul 27.

Authors

Huagang Xiao¹, Jiangnan Wang¹, Ruijie Zhang¹, Na Shan¹, Tao Gao²

Affiliations

¹ Institute of Atomic and Molecular physics, Sichuan University, Chengdu 610065, China.
² Institute of Atomic and Molecular physics, Sichuan University, Chengdu 610065, China; Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610065, China. Electronic address: gaotao@scu.edu.cn.

PMID: 35917619
DOI: 10.1016/j.saa.2022.121679

Abstract

We theoretically investigate the possibility of laser cooling ⁸⁷Sr³⁵Cl molecule in accordance with vibrational and hyperfine spectroscopy. The potential energy curves and dipole moment of the X²Σ⁺_1/2, A²Π_1/2,_3/2 and B²Σ⁺ states are calculated using ab initio method and the spectroscopic parameters are in good agreement with the experimental data. On account of the accurate potential energy curves and the transition dipole moment, the Franck - Condon factors and radiative lifetimes are predicted. Comparing the conditions of laser cooling candidate molecules, the A²Π _1/2 ↔ X²Σ⁺_1/2 transition is selected as the laser cooling cycle system. In order to obtain an approximately closed cooling cycle system, we employed matrix element algorithm to calculated the hyperfine spectroscopy and branching ratios of the ⁸⁷Sr³⁵Cl molecule. Furthermore, an electro-optical modulator (EOM) is designed including six hyperfine levels of the ground state X²Σ⁺_1/2 (v = 0, N = 1).