Abstract
The usage of nanoscale ferroelectric films as tunnel barriers in electronic devices offers a unique possibility to study the physics of ultrathin ferroelectric materials by means of electronic transport. In this letter, we simulate the current-voltage characteristics of a metal-ferroelectric-metal tunnel junction by use of a nonequilibrium Green's function approach. We discuss the role of quantum effects such as Friedel oscillations, which lead to deviations from the conventional semiclassical description of contacts in such a tunneling structure. As a consequence, we predict a well-pronounced bistable resistive switching effect, depending on the polarization state of the ferroelectric tunnel barrier.