1. School of Beile Engineering and Technology, Lanzhou City University, Lanzhou 730070, China; Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
2. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
3. School of Beile Engineering and Technology, Lanzhou City University, Lanzhou 730070, China.
4. College of Physical Science and Technology, Sichuan University, Chengdu 610065, China.