1. Hunan Key Laboratory of Super-Microstructure and Ultrafast Process, College of Physics and Electronics, Central South University, Changsha 410083, People's Republic of China
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, People's Republic of China
3. College of Science, National University of Defense Technology, Changsha 410073, China
4. State Key Laboratory of High Performance Computing, National University of Defense Technology, Changsha 410073, People's Republic of China
5. Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA