ABSTRACT
So far we have reviewed various aspects of graphene junctions
with nonmagnetic electrodes and magnetoresistive junctions with
magnetic electrodes. In electronics and/or spintronics applications
of graphene, detailed study on the transport phenomena of
graphene with electrodes is inevitable. In this chapter we study the
magnetoresistive properties of graphene junctions with magnetic
electrodes, typically with iron and nickel electrodes, by using the
same numerical method applied to investigate the GMR and TMR.
We will show that the junctions produce characteristic feature of
magnetoresistance (MR) distinct from GMR and TMR. Because of
the translational symmetry along the current direction is broken, we
start with model calculations for junctions using the single-orbital
tight-binding (TB) model, the results of which may give an intuitive
understanding of the characteristic properties of the MR, and the
model is easy to include the effects of disorder. We then proceed into
the realistic junctions using the full-orbital TB model. Before going
to the calculated resultwe present a short introduction to the subject
of MR of graphene junctions.
