Abstract for the 4th RPGR Workshop on Graphene (Times, 14pt, bold) Yeliang WANG1, A. H. Castro Neto2, and Hong-jun GAO1 (Times, 14pt) 1 Nanoscale Physics and Devices Laboratory, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China 2 Graphene Research Centre, Department of Physics, National University of Singapore, Singapore 117542, Singapore (Times, 12pt, italic) The 4th RPGR workshop on graphene will be held in Beijing, China, from Oct. 6 to Oct. 9, 2012 in the Institute of Physics, Chinese Academy of Sciences [1]. The abstract should fit in one A4 page (210 mm x 297 mm, portrait, printable area 160 mm x 240 mm – top/bottom margins of 30 mm and left/right margins of 25 mm). Please underline the presenting author. Please do not insert any page number, header or footer [2]. Please use a Times New Roman font. We appreciate you if you prepare a single Microsoft-WORD file and paste graphs and photos (if needed). There will be no editing process after your submission. (Times, 12pt) [1] Lei Meng, Rongting Wu, Haitao Zhou, et al., Appl. Phys. Lett. 100, 083101 (2012). [2] Jinhai Mao, Li Huang, Yi Pan, et al., Appl. Phys. Lett. 100, 093101 (2012). (Times, 11pt)