Direct evidence for interfacial superconductivity in two-layer semiconducting heterostructures

Abstract

We have discovered superconductivity in the two-layer semiconducting monochalcogenide heterostrutures $\mathrm{Pb}\mathrm{Te}∕\mathrm{Pb}\mathrm{S}$, $\mathrm{Pb}\mathrm{Te}∕\mathrm{Pb}\mathrm{Se}$ and $\mathrm{Pb}\mathrm{Te}∕\mathrm{Yb}\mathrm{S}$. By comparing data from two-layer samples with data from single monochalcogenide films we conclude that the superconductivity is connected with the interface between the two semiconductors. Evidence for the low dimensional nature of the superconducting interlayer is presented and a model that explains the appearance of single-interface superconductivity is proposed.