1. Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha 410082, China
2. Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA 92093, USA
3. Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Science and Technology Innovation Center, Zhejiang University, Hangzhou 310027, China
4. Department of Nano Engineering, University of California, San Diego, La Jolla, CA 92093, USA