About the Authors

Xiao-Jun Tian

Affiliation National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China

Feng Liu

fliu@nju.edu.cn (FL); wangwei@nju.edu.cn (WW)

Affiliation National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China

Xiao-Peng Zhang

Affiliation National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China

Jun Li

Affiliation National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China

Wei Wang

fliu@nju.edu.cn (FL); wangwei@nju.edu.cn (WW)

Affiliation National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: XJT FL XPZ. Performed the experiments: XJT. Analyzed the data: XJT FL XPZ JL WW. Contributed reagents/materials/analysis tools: FL WW. Wrote the paper: XJT FL.