1. Zernike Institute
for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
2. School of Physics and Technology, University of Jinan, 336 West Road
of Nan Xinzhuang, 250022 Jinan, P. R. China
3. Faculty of Physics, Moscow State University, Vorobyovy Gory, 119899 Moscow, Russia
4. School of Materials
Science and Engineering, Harbin Institute of Technology, 150001 Harbin, P. R. China
5. Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands