The original version of this article unfortunately missed acknowledgements part. The acknowledgements are as below. Acknowledgements We thank Prof. Decheng Wu for helping chemical synthesis. This work was supported by National Natural Science Foundation of China (Nos. 51121091, 21133001, 81421004, 21227803, and 21303004), Ministry of Science and Technology of China (Nos. 2014CB239303, 2013CB932601 and 2011CB808702), and the National Basic Research Program of China (973 Program, No. 2011CB707502).
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Condensed Matter Physics
- Electrical and Electronic Engineering