Non-linear I-V characteristics of Co/BTO/LSMO ferroelectric tunnel junction

The I-V curves of Co/BaTiO3/La0.67Sr0.33MnO3 ferroelectric tunnel junction have been calculated with the non-equilibrium Green function method at finite voltages. Compared to experimental data of a 2 nm thick barrier, our calculations match quantitatively the measurements at room temperature. Further analysis of the electric current shows that transport is done mainly by tunneling (direct and/or Fowler-Nordheim), while the part done through thermally activated resonant states is not relevant for a ferroelectric barrier thickness of 2 nm, but becomes dominant at 4 nm thickness.