1. Department of Physics and Chemistry Faculty of Science and Technology University of Macau Avenida da Universidade Taipa Macau 999078 China
2. Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials Engineering University of Macau Avenida da Universidade Taipa Macau 999078 China
3. Department of Physics Hong Kong Baptist University 224 Waterloo Road Kowloon Hong Kong SAR 999077 China