Observation of quasi-two-dimensional superconductivity at the EuO- BaBiO3 interface

The recent discoveries of superconducting oxide interfaces provide new platforms to explore the exotic superconducting properties in the two-dimensional (2D) regime. In this paper, we report the observation of quasi-2D superconductivity at the EuO/BaBiO₃ (001) interface with the superconducting transition temperature of ~3.5 K. The current-voltage characteristics reveal the signature of a Berezinski-Kosterlitz-Thouless transition, which indicates the existence of quasi-2D superconducting interface. Furthermore, the quasi-2D nature is also supported by the temperature- and angle-dependent upper critical fields. The realization of quasi-2D superconductivity in the BaBiO₃ heterostructures could be useful for the emergent research field of superconducting oxide interfaces.