Yao‐Tsung Hsieh1,2, Qifeng Han1,2,3, Chengyang Jiang1, Tze‐Bin Song1,2, Zhi‐Gang Chen1,2, Lei Meng1,2, Huanping Zhou1,2, Yang Yang1,2
1California NANOSystems Institute, University of California, Los Angeles, CA 90095, USA.
2Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095, USA
3Department of Physics, Shanghai Normal University, Shanghai 200234, China