Spin-orbit effects in a graphene bipolar pn junctionA. Yamakage1, K.-I. Imura1, 2, J. Cayssol2 and Y. Kuramoto1
1 Department of Physics, Tohoku University - Sendai, 980-8578, Japan
2 Condensed Matter Theory Group, CPMOH, UMR 5798, Université Bordeaux I - 33405 Talence, France, EU
received 3 June 2009; accepted in final form 7 August 2009; published August 2009
published online 4 September 2009
A graphene pn junction is studied theoretically in the presence of both intrinsic and Rashba spin-orbit couplings. We show that a crossover from perfect reflection to perfect transmission is achieved at normal incidence by tuning the perpendicular electric field. By further studying angular-dependent transmission, we demonstrate that perfect reflection at normal incidence can be clearly distinguished from trivial band gap effects. We also investigate how spin-orbit effects modify the conductance and the Fano factor associated with a potential step in both nn and np cases.
73.23.-b - Electronic transport in mesoscopic systems.
73.63.-b - Electronic transport in nanoscale materials and structures.
73.40.-c - Electronic transport in interface structures.
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