1. National
Lab for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
2. Cornell
High Energy Synchrotron Source, Wilson Laboratory, Cornell University, Ithaca, New York 14853, United States
3. HiPSEC,
Department of Physics and Astronomy, The University of Nevada, Las Vegas, Nevada 89154, United States
4. Geophysical
Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States