1. National Laboratory of Solid State Microstructures, School
of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
2. Stanford Institute of Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
3. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. Department
of Physics, University of California at Berkeley, Berkeley, California 94720, United States
5. CIC nanoGUNE, 20018 Donostia-San Sebastian, Spain
6. Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain
7. Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
8. Departamento
de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
9. Max Plank POSTECH Center for Complex Phase Materials, Pohang University of Science and Technology, Pohang 790-784, Korea
10. Geballe Laboratory for Advanced Materials,
Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305, United States
11. State Key Laboratory of Functional Materials
for Informatics, Shanghai Institute of Microsystem and Information
Technology, Chinese Academy of Sciences, Shanghai 200050, China
12. Department of Physics and Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1
3PU, United Kingdom
13. Department
of Physics, Pusan National University, Busan 609-735, Korea
14. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
15. Kavli Energy NanoScience Institute at the University of California Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States