1. Walter Schottky Institut and Physics Department Technical University of Munich 85748 Garching Germany
2. Munich Center for Quantum Science and Technology (MCQST) 80799 Munich Germany
3. Max‐Planck‐Institut für Festkörperforschung 70569 Stuttgart Germany
4. Center for Integrated Nanostructure Physics (CINAP) Institute for Basic Science (IBS) Suwon 16419 Republic of Korea
5. Department of Energy Science Sungkyunkwan University Suwon 16419 Republic of Korea
6. International Center for Materials Nanoarchitectonics National Institute for Materials Science Tsukuba 305‐0044 Japan
7. Research Center for Functional Materials National Institute for Materials Science Tsukuba 305‐0044 Japan