1. Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095, USA.
2. Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. China.
3. Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China.
4. Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, USA.
5. Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
6. UCLA Center for Quantum Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.