1. Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, & Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
2. Technische
Physik, Physikalisches Instität and Wilhelm Conrad Röntgen-Center
for Complex Material Systems, Universitat Würzburg, Am Hubland, D-97074 Wüzburg, Germany
3. SUPA,
School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom