*
Corresponding authors
a
Interdisciplinary Program in Nano-Science and Technology, Seoul National University, Seoul, Korea
b
Department of Physics and Astronomy, Seoul National University, Seoul, Korea
c
School of Electrical Engineering and Computer Science, Seoul National University, Seoul, Korea
d
Department of Materials Science and Engineering, Seoul National University, Seoul, Korea
e
Department of Physics, Sogang University, Seoul, Korea
f
Convergence Components & Materials Research Laboratory, ETRI, Daejeon, Korea
g
Department of Physics, Xinjiang University, Urumqi, Xinjiang, P. R. China
E-mail:
jikangjian@gmail.com
h
Department of Biophysics and Chemical Biology, Seoul National University, Seoul, Korea
E-mail:
seunghun@snu.ac.kr