1. National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Institute of Microelectronics, Peking University, Beijing 100871, China
2. Quantum Science and Engineering Centre, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
3. Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
4. Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
5. Institute of Microelectronics, A*STAR (Agency for Science, Technology and Research), Singapore 138634, Singapore