1. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
2. Hefei National Laboratory for Physical Sciences at the Microscale, Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
3. Department of Physics, North Carolina State University, Raleigh, NC 27695, USA
4. Ames Laboratory, U.S. Department of Energy, Ames, IA 50011, USA
5. Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA