  The possibility to develop neuromorphic computing devices able to mimic the
extraordinary data processing capabilities of biological systems spurs the
research on memristive systems. Memristors with additional functionalities such
as robust memcapacitance can outperform standard devices in key aspects such as
power consumption or miniaturization possibilities. In this work, we
demonstrate a large memcapacitive response of a perovskite memristive
interface, using the topotactic redox ability of
La$_{0.5}$Sr$_{0.5}$Mn$_{0.5}$Co$_{0.5}$O$_{3-\delta}$ (LSMCO, 0 $\leq$
$\delta$ $\leq$ 0.62). We demonstrate that the multi-mem behaviour originates
at the switchable n-p diode formed at the Nb:SrTiO3/LSMCO interface. We found
for our Nb:SrTiO$_{3}$/LSMCO/Pt devices a memcapacitive effect
C$_{HIGH}$/C$_{LOW}$ ~ 100 at 150 kHz. The proof-of-concept interface reported
here opens a promising venue to use topotactic redox materials for disruptive
nanoelectronics, with straightforward applications in neuromorphic computing
technology.
