[1] Chinese Acad Sci, State Key Lab Magnetism, Inst Phys, Beijing 100080, Peoples R China
[2] Chinese Acad Sci, Ctr Condensed Matter Phys, Beijing 100080, Peoples R China
[3] Hong Kong Univ Sci & Technol, Mat Characterizat & Preparat Fac, Magnet Innovat Ctr, MAGIC, Kowloon, Hong Kong, Peoples R China
[4] Univ Sci & Technol, Dept Phys, Kowloon, Hong Kong, Peoples R China