Low Voltage I-V Characteristics in Magnetic Tunnel Junctions
arXiv:cond-mat/0106123 · doi:10.1063/1.1433168
Abstract
We show that elastic currents that take into account variations of the tunnel transmitivity with voltage and a large ratio of majority to minority spin densities of states of the band, can account for the low voltage current anomalies observed in magnet-oxide-magnet junctions. The anomalies can be positive, negative or have a mixed form, depending of the position of the Fermi level in the band, in agreement with observations. Magnon contribution is negligible small to account for the sharp drop of the magnetoresistance with the voltage bias.
8 pages, 3 postscript figures