1. Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon16419, Republic of Korea
2. Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota55455, United States
3. Institute for Quantum Biophysics, Sungkyunkwan University, Suwon16419, Republic of Korea
4. Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
5. School of Mechanical Engineering, Sungkyunkwan University, Suwon16419, Republic of Korea
6. Department of Physics, University of Ulsan, Ulsan44610, Republic of Korea