1. Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, Key Laboratory of Strongly-Coupled Quantum Matter Physics (CAS), University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, P. R. China
2. National Institute
for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan