1. State Key Laboratory of Silicon Materials; School of Materials Science and Engineering; Zhejiang University; Hangzhou 310027 China
2. Research Laboratory for Quantum Materials; Singapore University of Technology and Design; Singapore 487372 Singapore
3. Department of Physics; National University of Singapore; Singapore 117542 Singapore
4. Department of Physics; Applied Physics, and Astronomy; Rensselaer Polytechnic Institute; Troy NY 12180 USA