Alloying with Ga promotes superconductivity in single-atomic Pb layer on Si(111)

Abstract

Alloying of the single-atom-thick Pb film on Si(111), the so-called striped incommensurate SIC-3×3-Pb phase, with Ga has been found to result in the formation of the ordered 2D layer having the 43×43 periodicity. In situ transport measurements have shown that the layer is superconductor with the critical temperature Tc = 2.48 K, which sufficiently exceeds the critical temperatures of the SIC-3×3-Pb phase and bulk Ga. This finding opens the new ways to control low-dimensional superconductivity at the atomic scale limit through alloying appropriate species and get a success even when it does not take place in the case of the same bulk materials.