1. Department of Physics and William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 999077, Hong Kong Special Administrative Region of the People’s Republic of China
2. School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People’s Republic of China
3. Department of Mechanical Engineering, The University of Hong Kong, Pok Fu Lam 999077, Hong Kong Special Administrative Region of the People’s Republic of China