* Corresponding authors

^a Ames National Laboratory, U.S. Department of Energy, Ames, IA 50011, USA

^b Department of Applied Physics, College of Science, Zhejiang University of Technology, Hangzhou, China

^c Jiyang College of Zhejiang Agriculture, Forestry University, Zhuji 311800, China

^d Department of Physics, Yantai University, Yantai 264005, China

^e Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA

^f Department of Chemistry, Iowa State University, Ames, IA 50011, USA