  Complex oxide heterointerfaces can host a rich of emergent phenomena, and
epitaxial growth is usually at the heart of forming these interfaces. Recently,
a strong crystalline-orientation-dependent two-dimensional superconductivity
was discovered at interfaces between KTaO3 single-crystal substrates and films
of other oxides. Unexpectedly, rare of these oxide films was epitaxially grown.
Here, we report the existence of superconductivity in epitaxially grown
LaVO3/KTaO3(111) heterostructures, with a superconducting transition
temperature of ~0.5 K. Meanwhile, no superconductivity was detected in the
(001)- and (110)-orientated LaVO3/KTaO3 heterostructures down to 50 mK.
Moreover, we find that for the LaVO3/KTaO3(111) interfaces to be conducting, an
oxygen-deficient growth environment and a minimum LaVO3 thickness of ~0.8 nm (~
2 unit cells) are needed.
