1. College of Science, China Jiliang University, 258 Xueyuan Street, Hangzhou 310018, China e-mail:
2. Department of Mining and Materials Engineering, McGill University, 3450 University Street, Montreal, QC H3A2A7, Canada e-mail:
3. School of Physics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China e-mail: