1. Department of Physics, University of Seoul, Seoul 02504, Republic of Korea
2. Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
3. Advanced Light Source (ALS), E. O. Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. Centre for Nanoscience and Nanotechnology and Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom
5. Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
6. Department of Physics, Sogang University, Seoul 04107, Republic of Korea
7. Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
8. Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
9. Department of Physics, Sejong University, Seoul 05006, Republic of Korea