Effects of magnetic barriers on transport and magnetoresistance in a two-dimensional electronic device

We study theoretically the giant magnetoresistance (GMR) effect of 2-dimensional electron system (2DES) by the transfer matrix method. To produce the inhomogeneous magnetic field, two magnetic strips are pre-deposited on the surface of 2DES. In our work, we fix the magnetization M in one magnetic strip and adjust the tilting angle θ of magnetization in the other. The result shows that the electronic transmission and conductance vary significantly for different θ. The minimum conductance can be obtained at θ = π which corresponds to the magnetization anti-parallel alignment. The magnetoresistance ratio (MRR) calculation also indicates we would get the maximum in that case. Furthermore, we consider the magnetization M dependence of MRR in this work. When M increases, MRR peaks get higher and broader and more numbers of peaks can be observed. These results offer an alternative to get a tunable GMR device which can be controlled by adjusting the magnetization M and the magnetized angle θ.