1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
3 Songshan Lake Materials Laboratory, Dongguan, 523808, P. R. China.
4 State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, P. R. China.
5 School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China.
6 Department of Materials Science and Engineering, Center of Electron Microscopy and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, 310027, P. R. China.
7 Institute of Physics, Academy of Sciences of the Czech Republic, Praha, 180 40, Czech Republic.
8 Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York, 11973, USA. [email protected].
9 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China. [email protected].
10 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China. [email protected].
11 Songshan Lake Materials Laboratory, Dongguan, 523808, P. R. China. [email protected].
12 Department of Materials Science and Engineering, University of Illinois at Urbana Champaign, 1304 W Green St, Urbana, 61801, USA.
13 Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, New York, 11973, USA.
14 Beijing National Center for Electron Microscopy, Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084, P. R. China.