1. Xi’an Jiaotong University, School of Information and Communications Engineering, Xi’an, China and University of Alberta, Department of Physics, Edmonton, Alberta, Canada.
2. Shanghai Luoshu Investments Co. Ltd., Shanghai, China.
3. Xi’an Jiaotong University, School of Information and Communications Engineering, Xi’an, China.
4. University of Alberta, Department of Physics, Edmonton, Alberta, Canada.
5. Xi’an Jiaotong University, School of Information and Communications Engineering, Xi’an, China. (corresponding author)