Superconductivity in epitaxially grown LaVO₃/KTaO₃(111) heterostructures

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.