Similarities of coherent tunneling spectroscopy of ferromagnet/ferromagnet junction within two interface models: Delta potential and finite width model

Abstract

The tunneling conductance spectra of a ferromagnet/ferromagnet junction was theoretically studied under a scattering approach using two models of the interface: delta potential and finite width model in a one dimensional system. In the first model, the interface between the materials was characterized by the delta potential that has infinite height but no width. For the other model, the interface was modeled by an insulator with a finite thickness and potential barrier height. As a result, it was found that the potential strength under the delta potential model suppressed the conductance spectra as expected. In the finite width model, the insulating layer can give rise to an oscillation behavior when the layer is thick. This oscillation occurs in the region of the energy that is larger than the potential barrier. Moreover, the conductance spectra was suppressed by varying the insulating thickness, also depending on how high the potential barrier was. When the results from the two models were compared, they gave rise to the same result when the insulating layer was thin and the potential barrier was slightly larger than the energy of the bottom of the minority band of the ferromagnet.