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 similar to 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 similar to 0.8 nm (similar to 2 unit cells) are needed.

Automated summary

A crystalline-orientation-dependent two-dimensional superconductivity was found at interfaces between KTaO3 single-crystal substrates and films of other oxides. Epitaxially grown LaVO3/KTaO3(111) heterostructures exhibit superconductivity with a transition temperature of around 0.5 K, while no superconductivity was observed in the (001)- and (110)-orientated heterostructures. To enable conductivity in LaVO3/KTaO3(111) interfaces, an oxygen-deficient growth environment and a minimum LaVO3 thickness of about 0.8 nm (around 2 unit cells) are required.