1. Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, United States
2. Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China
3. Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
4. DTU Nanolab, Technical University of Denmark, Kongens Lyngby 2800, Denmark
5. Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China