  This paper proposes a new model for Giant Magnetoresistance (GMR) and
calculates its typical graph qualitatively. The model foundation is the
microscopic mechanism in GMR, where the GMR effect can be explained by
intrinsic and extrinsic potential. The potentials are spin-dependent. The
potentials determine the transmission probability then it will give conductance
value. Here, the multiple barrier potential model is proposed as the new GMR
model. The transmission probability is determined using transfer matrix method.
It was found that this model is fit qualitatively with the typical GMR graph.
