Issue
EPL
Volume 87, Number 4, August 2009
Article Number 47005
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/87/47005
Published online 04 September 2009
EPL, 87 (2009) 47005
DOI: 10.1209/0295-5075/87/47005

Spin-orbit effects in a graphene bipolar pn junction

A. 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

j.cayssol@cpmoh.u-bordeaux1.fr

received 3 June 2009; accepted in final form 7 August 2009; published August 2009
published online 4 September 2009

Abstract
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.

PACS
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.

© EPLA 2009