Protective layer enhanced the stability and superconductivity of tailored antimonene bilayer

For two-dimensional superconductors, the high stability in ambient conditions is critical for experiments and applications. Few-layer antimonene can be nondegradative over a couple of months, which is superior to the akin black phosphorus. Based on the anisotropic Migdal-Eliashberg theory and maximally-localized Wannier functions, this work predicts that electron-doping and Ca-intercalation can transform beta-Sb bilayer from a semimetal to a superconductor. However, the stability of antimonene bilayer in air trends to be decreased due to the electron doping. To overcome this drawback, two kinds of protective layers (graphene and h-BN) are proposed to enhance the stability. Interestingly, the superconducting transition temperature will also be enhanced to 9.6 K, making it a promising candidate as nanoscale superconductor.