1. DGIST Research Institute, DGIST, Daegu 42988, Korea
2. Department of Emerging Materials Science, DGIST, Daegu 42988, Korea
3. Korea Research Institute of Standards and Science, Daejeon 34113, Korea
4. Institute of Next Generation Semiconductor Technology (INST), DGIST, Daegu 42988, Korea
5. Department of Interdisciplinary Engineering, DGIST, Daegu 42988, Korea
6. Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
7. Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland
8. Swiss Nanoscience Institute (SNI), University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland