Epitaxial growth of one‐monolayer Pb _1‐x Bi _x alloy films

Motivated by recent theoretical reports of intrinsic topological superconductivity in Pb3Bi alloy systems where large Rashba gap and type II van Hove singularity coexist, one-monolayer Pb1-xBix alloy films have been successfully grown by molecular beam epitaxy technique and systematically investigated by scanning tunneling microscope and spectroscopy in this work. There coexist two different stable phases in the Pb1-xBix alloyed films: 3 × 3 semiconducting phase with band gap as large as to 0.6eV, and 3√3 × 3√3 metallic phase. Furthermore, the formation of the two different Pb1-xBix monolayer films can be tuned by changing the Bi content and annealing processes. These findings have paved the way for further exploration of superconductivity and topological properties of the PbxBi1-x systems. This article is protected by copyright. All rights reserved.