1. School of Materials Science and Engineering
2. Tianjin University
3. Tianjin 300350
4. China
5. Department of Physics
6. Tokyo Metropolitan University
7. Tokyo 192-0397
8. Japan
9. Laboratory of Solid State Physics and Magnetism
10. KU Leuven
11. 3001 Leuven
12. Belgium
13. Atomic, Molecular & Optical Physics Laboratory
14. RIKEN
15. Saitama 351-0198
16. Department of Chemistry
17. University of Gothenburg
18. 41296 Gothenburg
19. Sweden
20. Center for Joint Quantum Studies and Department of Physics