1. Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
2. Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
3. Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
4. Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
5. Center for van der Waals Quantum Solids, Institute for Basic Science (IBS), Pohang 37673, Republic of Korea
6. Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan
7. International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba 305-0044, Japan