Gold Interlayer Promotes Superconductivity in Single and Double Atomic Pb Layers on Si(100)

Introducing an atomic Au monolayer between a Pb film and a Si(100) substrate allows us to fabricate Pb films with single- and double-atom thicknesses. The Pb films have a 2D square-lattice structure with the 1D atomic chains of Pb adatoms on their top, forming Si(100)1 X 7-(Pb, Au) and Si(100)5 x 1-(Pb, Au) superstructures for single and double atomic Pb layers, respectively. Their common characteristic feature is the occurrence of bundles of quasi-1D metallic bands. Transport measurements showed that samples with a Au interlayer demonstrate enhanced superconductor properties, as compared to Pb layers grown on the bare Si(100) surface. Toward improved superconductor properties, the (Pb, Au)/Si(100) system successively avoids risks associated with possible intermixing between adsorbate layers and substrate, as well as with possible Peierls transition into an insulator state, typical for the 1D systems. This finding opens new ways to control low-dimensional superconductivity at the atomic-scale limit.

Automated summary

“” By introducing an atomic Au monolayer between a Pb film and a Si(100) substrate, it is possible to fabricate Pb films with single- and double-atom thicknesses. These films exhibit a 2D square-lattice structure with 1D atomic chains of Pb adatoms on the top, resulting in Si(100)1 X 7-(Pb, Au) and Si(100)5 x 1-(Pb, Au) superstructures for single and double atomic Pb layers, respectively. The common characteristic feature is the presence of bundles of quasi-1D metallic bands. It was observed that samples with a Au interlayer show enhanced superconductor properties compared to Pb layers grown on bare Si(100) surface. This finding opens up new possibilities for controlling low-dimensional superconductivity at the atomic scale.