National Laboratory for Superconductivity, Institute of Physics and National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190;
National Laboratory for Superconductivity, Institute of Physics and National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190;
National Laboratory for Superconductivity, Institute of Physics and National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190;
National Laboratory for Superconductivity, Institute of Physics and National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190;
National Laboratory for Superconductivity, Institute of Physics and National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190;
National Laboratory for Superconductivity, Institute of Physics and National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190;
Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA;
Department of Physics, Peking University, Beijing 100871;
Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA;
Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA;
Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA;
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA;
