The interplay between the electron transport in metal-ferroelectric-metal junctions with ultrathin ferroelectric barriers and the polarization state of a barrier is investigated. Using a model which takes into account screening of polarization charges in metallic electrodes and direct quantum tunneling across a ferroelectric barrier, we calculate the change in the tunneling conductance associated with the polarization switching. We find the conductance change of a few orders of magnitude for metallic electrodes with significantly different screening lengths. This giant electroresistance effect is the consequence of a different potential profile seen by transport electrons for the two opposite polarization orientations.
Zhuravlev, Mikhail Y.; Sabirianov, Renat F.; Jaswal, Sitaram; and Tsymbal, Evgeny Y., "Giant Electroresistance in Ferroelectric Tunnel Junctions" (2005). Physics Faculty Publications. 28.