1. Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX 77204, USA
2. Department of Electrical and Computer Engineering, University of Houston, Houston, TX 77204, USA
3. College of Physical Science and Technology, Central China Normal University, Wuhan, 430079, China
4. Department of Chemistry, The Chinese University of Hong Kong, Hong Kong SAR, China