Zhen Chai1, Xiaoyong Hu1,2,*, Feifan Wang1, Chong Li1, Yutian Ao1, You Wu1, Kebin Shi1,2, Hong Yang1,2 and Qihuang Gong1,2
1 State Key Laboratory for Mesoscopic Physics & Department of Physics, Collaborative Innovation Center of Quantum Matter, Peking University, Beijing, P. R. China
2 Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, P. R. China