1. Department of Electrical and Computer Engineering Texas Center for Superconductivity (TCSUH) University of Houston Houston TX 77204 USA
2. Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Chengdu Sichuan 610054 China
3. CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology Beijing 100190 China
4. Department of Mechanical Engineering University of Houston Houston TX 77204 USA
5. Department of Physics and Texas Center for Superconductivity University of Houston Houston TX 77204 USA