1. Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan, Department of Physics, Wuhan University, Wuhan 430072, China, College of Mathematics and Physics, Nanjing University of Information Science and Technology, Nanjing 210044, China, Department of Chemistry, National Taiwan Normal University, Taipei 106, Taiwan, Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, and Institute of Physics, Academia Sinica, Taipei 115, Taiwan