The Theoretical Research About Magnetoresistance In The Double Ferromagnetic Semiconductor Junction

In this thesis, the tunneling magnetoresistance (TMR) in the nonmagnetic metal/ferromagnetic semiconductor/ferromagnetic semiconductor/nonmagnetic metal double ferromagnetic semiconductor junctions has been studied.Firstly, in this thesis, the background and the current status in the field of magnetic tunneling junction are introduced. Next, based on the nearly free electron model of Slonczewski, we afford a simple transfer matrix method that can be used to calculate the spin polarized transport in complex tunneling junction structure. Based on this method, the TMR of the NM/FS/FS/NM double ferromagnetic semiconductor junctions have been studied. Our theoretical results show that, for the NM/FS/FS/NM junction, when the thickness of the FS layer is changed, the TMR is changed periodly. The large TMR can be obtained by adjusting the thickness of the FS layer, Rashba spin-orbit coupling coefficient and angle of magnetic moment.The FS material has widely used in the spin electronic devices, quantum compute and quantum commmunication. In addition, there exist spin and orbit of transport electron coupling (Rashba spin-orbit coupling) in FS material. So the theoretical research about the spin-polarized electronic transport in NM/FS/FS/NM double ferromagnetic semiconductor junction would be helpful for us to further understand the influence of Rashba spin-orbit coupling in the quantum tunneling phnenomena.