  An interface modification of LCMO-BTO superlattices was found to massively
influence magnetic and magnetotransport properties. Moreover it determines the
crystal structure of the manganite layers, changing it from orthorhombic (Pnma)
for the conventional superlattice (cSL), to rhombohedral (R-3c) for the
modified one (mSL). While the cSL shows extremely nonlinear ac transport, the
mSL is an electrically homogeneous material. The observations go beyond an
oversimplified picture of dead interface layers and evidence the importance of
electronic correlations at perovskite interfaces.
