Tunnel barrier parameters and magnetoresistance in the parabolic band model

Abstract

Tunnel magnetoresistance (MR) is studied in the framework of the parabolic band model. Coherent transport and electronic wave function interferences in the barrier are shown to play an important role even for a single barrier. The influence of the barrier parameters on magnetoresistance and on its bias dependence is compared with success to experiments. The shape of the barrier is then considered as it can account for asymmetries observed in MR(V) curves. Finally, despite its simplicity, this model predicts qualitatively the complex MR(V) observed in composite barriers. © 2001 The American Physical Society.