  In strongly correlated oxides, heterointerfaces, manipulating the
interaction, frustration, and discontinuity of lattice, charge, orbital, and
spin degrees of freedom, generate new possibilities for next generation
devices. In this study, we went back to examine the existing oxide
heterostructures and found the local conduction at the BiFeO3-CoFe2O4 vertical
interface. In such hetero-nanostructure, the tubular interface, surrounding
BiFeO3-CoFe2O4 vertical interface, can not only be the medium to the coupling
between phases, but also be a new state of the matter. Our study demonstrates a
novel concept on oxide interface design and opens a pathway alternative for the
explorations of diverse functionalities in complex oxide interfaces.

Materials Science