1. Department of Materials Science and Engineering Korea University Seoul 02841 Republic of Korea
2. Department of Semiconductor Systems Engineering Korea University Seoul 02841 Republic of Korea
3. School of Electrical Engineering Korea University Seoul 02841 Republic of Korea
4. Samsung Advanced Institute of Technology Samsung Electronics Suwon Gyeonggi‐do 16678 Republic of Korea
5. Department of Physics and Astronomy Seoul National University Seoul 08826 Republic of Korea