The oxide interface between ${\mathrm{La}\mathrm{Al}\mathrm{O}}_3$ and ${\mathrm{KTaO}}_3(111)$ can host an electron gas that condenses into superconductivity at low temperatures. In this work, we demonstrate a local and nonvolatile control of this electron gas using a biased conducting atomic force microscope tip. By scanning the tip, charges can be accumulated on the surface of ${\mathrm{La}\mathrm{Al}\mathrm{O}}_3$, which subsequently tune the conduction of the buried ${\mathrm{La}\mathrm{Al}\mathrm{O}}_3/{\mathrm{KTaO}}_3(111)$ interface largely, varying from conducting (superconducting) to insulating states. The tuning effects are stable for >20 h at room temperature. The maximum modulation of carrier density is >8 × ${10}^{13}/{\mathrm{cm}}^2$. This result suggests a model system in which rewritable superconducting, normal, and insulating states can be flexibly defined in the same material on demand.

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• Charge
• Superconductivity
• Surface & interfacial phenomena
• Solid-solid interfaces
• Thin films
• Transition metal oxides
• Atomic force microscopy
• Scanning probe microscopy