  Memristive switching serves as the basis for a new generation of electronic
devices. Memristors are two-terminal devices in which the current is turned on
and off by redistributing point defects, e.g., vacancies, which is difficult to
control. Memristors based on alternative mechanisms have been explored, but
achieving both the high On/Off ratio and the low switching energy desirable for
use in electronics remains a challenge. Here we report memristive switching in
a La0.7Ca0.3MnO3/PrBa2Cu3O7 bilayer with an On/Off ratio greater than 10^3 and
demonstrate that the phenomenon originates from a new type of interfacial
magnetoelectricity. Using results from first-principles calculations, we show
that an external electric-field induces subtle displacements of the interfacial
Mn ions, which switches on/off an interfacial magnetic "dead" layer, resulting
in memristive behavior for spin-polarized electron transport across the
bilayer. The interfacial nature of the switching entails low energy cost about
of a tenth of atto Joule for write/erase a "bit". Our results indicate new
opportunities for manganite/cuprate systems and other transition-metal-oxide
junctions in memristive applications.
