[1] Hong Kong Polytech Univ, Inst Text & Clothing, Hong Kong, Hong Kong, Peoples R China
[2] Tsinghua Univ, Innovat Ctr Quantum Matter, State Key Lab Low Dimens Quantum Phys & Collabora, Dept Phys, Beijing 100084, Peoples R China
[3] Natl Ctr Nanosci & Technol, Beijing 100190, Peoples R China