School of Physics, Materials Physics Laboratory, Peking University, Beijing 100871;
Research Center for Wide-Band Semiconductors, Peking University, Beijing 100871;
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871;
School of Physics, Materials Physics Laboratory, Peking University, Beijing 100871;
Research Center for Wide-Band Semiconductors, Peking University, Beijing 100871;
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871;
School of Physics, Materials Physics Laboratory, Peking University, Beijing 100871;
Research Center for Wide-Band Semiconductors, Peking University, Beijing 100871;
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871;
School of Physics, Materials Physics Laboratory, Peking University, Beijing 100871;
Research Center for Wide-Band Semiconductors, Peking University, Beijing 100871;
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871;
School of Physics, Materials Physics Laboratory, Peking University, Beijing 100871;
Research Center for Wide-Band Semiconductors, Peking University, Beijing 100871;
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871;
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049;
School of Physics, Materials Physics Laboratory, Peking University, Beijing 100871;
Research Center for Wide-Band Semiconductors, Peking University, Beijing 100871;
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871;
School of Physics, Materials Physics Laboratory, Peking University, Beijing 100871;
Research Center for Wide-Band Semiconductors, Peking University, Beijing 100871;
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871;
School of Physics, Materials Physics Laboratory, Peking University, Beijing 100871;
Research Center for Wide-Band Semiconductors, Peking University, Beijing 100871;
School of Physics, Materials Physics Laboratory, Peking University, Beijing 100871;
Research Center for Wide-Band Semiconductors, Peking University, Beijing 100871;
State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871;
