A Two-Dimensional Superconducting Electron Gas at LaFeO3/SrTiO3 Interfaces

Transition metal oxide interfaces have garnered great attention due to their fascinating properties that are absent in their bulk counterparts. The high mobility and coexistence of superconductivity and magnetism at these interfaces remain compelling research topics. Here, we first report superconductivity in the 2DEG formed at the LaFeO3/SrTiO3 interfaces, characterized by a superconducting transition temperature (T c) of 333 mK and a superconducting layer thickness of 13.7 nm. The observation of a Berezinskii-Kosterlitz-Thouless transition at low temperatures indicates the two-dimensional nature of the superconductivity. Such two-dimensional superconductivity can be tuned by applying a gate voltage (V g) across the SrTiO3 substrate, showing a dome-shaped T c-V g dependence. Moreover, we observe a hysteretic behavior in the magnetoresistance in the superconducting regime, and the underlying mechanism requires further investigation. Our results unveil the superconducting characteristics of 2DEG at LaFeO3/SrTiO3 interfaces and offer a new compelling platform to investigate emergent quantum phenomena at oxide interfaces.