  We investigate hysteresis effects in a model for non-volatile memory devices.
Two mechanisms are found to produce hysteresis effects qualitatively similar to
those often experimentally observed in heterostructures of transition metal
oxides. One of them is a novel switching effect based on a metal-insulator
transition due to strong electron correlations at the dielectric/metal
interface. The observed resistance switching phenomenon could be the
experimental realisation of a novel type of strongly correlated electron
device.
