**Author details**

Jing Xu<sup>1</sup> , Li-Fang Xu<sup>2</sup> \*, Jian-Tao Wang2,3 and Annabella Selloni4

\*Address all correspondence to: lfxu@iphy.ac.cn

1 Beijing Key Laboratory of Optoelectronic Functional Materials and Micro-nano Devices, Department of Physics, Renmin University of China, Beijing, China

2 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China

3 School of Physics, University of Chinese Academy of Sciences, Beijing, China

4 Department of Chemistry, Princeton University, Princeton, New Jersey, USA
