International Journal of Modern Physics B Vol. 31, No. 6 (2017) 1750043 (10 pages) c  World Scientific Publishing Company DOI: 10.1142/S0217979217500436 Effects of Rashba spin orbit coupling on the conductance of graphene-based nanoribbons Zeinab Rashidian *,‡ , Parvin Bayati † and Zeinab Lorestaniwiess * * Department of Physics, Faculty of Science, Lorestan University, Lorestan, Iran † Department of Physics, Faculty of Science, Zanjan University, Zanjan, Iran ‡ fatima1983d@gmail.com Received 14 March 2016 Revised 29 September 2016 Accepted 28 October 2016 Published 21 December 2016 The transmission properties of armchair- and zigzag-edged graphene nanoribbon junc- tions between graphene electrodes are examined by means of the standard nonequilib- rium Green’s function (NEGF) technique. The quantum transport of electrons is studied through a monolayer graphene strip in the presence of Rashba spin–orbit coupling that acts as a barrier between the two normal leads. The present work compares the con- ductances of nanoribbons with zigzag and armchair edges. Since the nature of induced gap for zigzag edge is different from armchair, it is expected to give rise to different types of conductance for each edge. Findings indicate that the Rashba strength has more pronounced influence on armchair ribbons than on zigzag ribbons, and the min- imum conductance of 2G 0 for nanoribbon remains intact even in the presence of the Rashba spin–orbit coupling. It is predicted that controllability of spin transport in the monolayer graphene may contribute to the development of well-known spintronics. Keywords : Graphene; non-equilibrium Green’s Function Technique; Landauer–Buttiker formula; Rashba spin–orbit coupling; nanoribbon. PACS numbers: 73.22.Pr, 75.50.Pp, 75.70.Tj 1. Introduction The lack of bandgap in graphene hinders its application in technology and industry in spite of its many intriguing and unique properties. One strategy for inducing gap for the monolayer graphene is to produce a one-dimensional graphene strip, namely, the graphene nanoribbon (GNR). 1 ‡ Corresponding author. 1750043-1