Department of Physics,Tsinghua University,Beijing,100084;
Department of Physics,Tsinghua University,Beijing,100084;
Department of Physics,Vanderbilt University,Nashville,Tennessee,37235,USA;
Department of Physics,Vanderbilt University,Nashville,Tennessee,37235,USA;
Department of Physics,Vanderbilt University,Nashville,Tennessee,37235,USA;
Department of Physics,Tsinghua University,Beijing,100084;
Department of Physics,Tsinghua University,Beijing,100084;
Department of Physics,Tsinghua University,Beijing,100084;
Department of Physics,Tsinghua University,Beijing,100084;
Lawrence Berkeley National Laboratory,Berkeley,California,94720,USA;
Lawrence Berkeley National Laboratory,Berkeley,California,94720,USA;
Department of Physics,Vanderbilt University,Nashville,Tennessee,37235,USA;
Lawrence Berkeley National Laboratory,Berkeley,California,94720,USA;
Department of Physics,Mississippi State University,Mississippi,39762,USA;