1. Department of Physics,
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative
Innovation Center for Optoelectronic Semiconductors and Efficient
Devices, Xiamen University, Xiamen 361000, China
2. Pen-Tung Sah Institute of Micro-Nano Science
and Technology, Xiamen University, Xiamen 361005, China
3. Institute for Complex Adaptive Matter, University of California, Davis, California 95616, United States