  The operation of a novel nonvolatile memory device based on a conductive
ferroelectric/non-ferroelectric thin film multilayer stack is simulated
numerically. The simulation involves the self-consistent steady state solution
of Poisson's equation and the transport equation for electrons assuming a
Drift-Diffusion transport mechanism. Special emphasis is put on the screening
of the spontaneous polarization by conduction electrons as a function of the
applied voltage. Depending on the orientation of the polarization in the
ferroelectric layer, a high and a low resistive state are found giving rise to
a hysteretic I-V characteristic. The R_high to R_low ratio ranging from > 50%
to several orders of magnitude is calculated as a function of the dopant
content.
