Tunable superconductivity at KTaO₃ (111) interface

The discovery of superconductivity at the oxide-insulator/KTaO₃ interface provides a new platform for investigating interfacial superconductivity. Exploring how the superconductivity in this system may be tuned is of great importance to both fundamental research and scientific applications. Here, we report on a strong tunability of superconductivity at the KTaO3 (111) interface by varying the carrier density via chemical doping, as well as through electrostatic gating. We show that the superconducting transition temperature T_c is strongly dependent on carrier density over a range of nearly one order of magnitude, while it is insensitive to the disorder level present in the as grown samples. The measured Ginzburg-Landau coherence length show a scaling law in these samples over the entire doping range. Our electrostatic gating measurements on samples with different doping levels show a monotonic dependence of the mean-field T_c on eigher the applied electric field or on the electrostatically induced carriers.