1. College of Physics; Laboratory of Fiber Materials and Modern Textile; the Growing Base for State Key Laboratory; and Key Laboratory of Photonics Materials and Technology in Universities of Shandong; Qingdao University; Qingdao 266071 P.R. China
2. National Laboratory of Solid State Microstructures; Nanjing University; Nanjing 210093 P.R. China
3. Department of Electrical and Computer Engineering; Institute for Quantum Computing; University of Waterloo; Waterloo N2L 3G1 Canada
4. School of Physics; Shandong University; Jinan 250100 P.R. China
5. Collaborative Innovation Center for Low-Dimensional Nanomaterials and Optoelectronic Devices; Qingdao University; Qingdao 266071 P.R. China
6. School of Chemical Science and Engineering; Qingdao University; Qingdao 266071 P.R. China
7. Department of Physics; School of Science; Harbin Institute of Technology; Harbin 150001 P.R. China