Epitaxial Growth of One‐Monolayer Pb1−xBix Alloy Films

Abstract

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 Pb 1− x Bi x alloy films have been successfully grown by molecular beam epitaxy technique and systematically investigated by scanning tunneling microscopy and spectroscopy in this work. There coexist two different stable phases in the Pb 1− x Bi x alloyed films: 3 × 3 semiconducting phase with a bandgap as large as 0.6 eV, and 3√3 × 3√3 metallic phase. Furthermore, the formation of the two different Pb 1− x Bi x monolayer films can be tuned by changing the Bi content and annealing processes. These findings pave the way for further exploration of superconductivity and topological properties of the Pb x Bi 1− x systems.