1. School of Electrical Engineering Korea Advanced Institute of Science and Technology 291 Daehak‐ro Daejeon 34141 Republic of Korea
2. Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology 291 Daehak‐ro Daejeon 34141 Republic of Korea
3. Quantum Functional Semiconductor Research Center Dongguk University Joong‐gu Seoul 04620 Republic of Korea