Observation of two-dimensional superconductivity in bilayers of BaBiO3 and BaPbO3

Lead-doped barium bismuthate is intriguing because of its relatively high critical temperature and the nature of its superconductivity in the vicinity of a charge-density-wave-ordered topological insulator. Here we present bilayers of barium bismuthate and barium leadate showing emergent superconductivity as a function of the barium leadate top layer thickness. Magnetotransport studies allow for the characterization of the superconducting properties in these bilayers to be two-dimensional. In addition current-voltage characteristics of superconducting bilayers reveal signatures of a Berezinski\ifmmode \breve{\imath}\else \u{\i}\fi{}-Kosterlitz-Thouless transition. The particular observed dependence of the superconducting transition temperature on the thickness of the barium leadate top layer suggests the formation of the superconducting state originating from the interface.