1. High
Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui 230031, P. R. China
2. Department
of Nano Fusion Technology and BK21 Plus Nano Convergence Technology
Division, Pusan National University, Busan 609-735, Republic of Korea
3. Department
of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Republic of Korea
4. Key
Laboratory of Materials Physics, Centre for Environmental and Energy
Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology,
Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, P. R. China
5. Office
of General Education, Pusan National University, Busan 609-735, Republic of Korea