1. Songshan Lake Materials Laboratory Dongguan 523808 P. R. China
2. Spallation Neutron Source Science Center Dongguan 523803 P. R. China
3. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 P. R. China
4. Institute of Materials Structure Science High Energy Accelerator Research Organization (KEK) Tokai Ibaraki 319‐1106 Japan
5. J‐PARC Center High Energy Accelerator Research Organization (KEK) Tokai Ibaraki 319‐1106 Japan
6. Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 P. R. China