1. Department of Applied Physics, School of Science, Nanjing University of Science and Technology, 210094 Nanjing, China
2. Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden
3. Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697, United States
4. Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China, 230026 Hefei, China