1. Key
Laboratory of Materials Physics, Institute of Solid State Physics,
Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031, P. R. China
2. High
Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei 230031, P. R. China
3. School
of Mathematics and Physics, Shanghai University of Electric Power, No.
2588 Changyang Road, Shanghai 200090, P. R. China