1. Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
2. School of Physics, KIAS, Seoul 02455, Republic of Korea
3. Department of Materials Science and Engineering, POSTECH, Pohang 37673, Republic of Korea
4. Center for Epitaxial van der Waals Quantum Solids, Institute for Basic Science (IBS), Pohang 37673, Republic of Korea
5. Department of Chemical Engineering, POSTECH, Pohang 37673, Republic of Korea
6. Department of Physics, POSTECH, Pohang 37673, Republic of Korea
7. Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Republic of Korea