Biao Yang1,*, Qinghua Guo1,4,*, Ben Tremain2,*, Rongjuan Liu3,*, Lauren E. Barr2, Qinghui Yan3, Wenlong Gao1, Hongchao Liu1, Yuanjiang Xiang4, Jing Chen5, Chen Fang3, Alastair Hibbins2,?, Ling Lu3,?, Shuang Zhang1,?
1 School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK.
2 Electromagnetic and Acoustic Materials Group, Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK.
3 Institute of Physics, Chinese Academy of Sciences/Beijing National Laboratory for Condensed Matter Physics, Beijing 100190, China.
4 Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
5 School of Physics, Nankai University, Tianjin 300071, China.
? Corresponding author.
* These authors contributed equally to this work.
