The superconducting properties of a Pb/MoTe₂/Pb heterostructure:First-principles calculations within the anisotropic Migdal-Eliashberg theory

The spin-polarized band structures of an ultrathin Pb/MoTe₂/Pb heterostructure are calculated via first-principles density functional theory. The electron-phonon interaction and the superconducting properties of the ultrathin Pb/MoTe₂/Pb heterostructure are studied by using the fully anisotropic Migdal-Eliashberg theory powered by Wannier-Fourier interpolation. Due to the complex Fermi surface in this low-dimensional system, the electron-phonon interaction and the superconducting gap display significant anisotropy. The temperature dependence of the superconducting gap can be fitted by solving numerically the Bardeen-Cooper-Schrieffer (BCS) gap equation with an adjustable parameter α, suggesting that phonon-mediated mechanism as its superconducting origin. Large Rashba spin-splitting and superconductivity coexist in this heterostructure, suggesting that this hybrid low-dimensional system will have some specific applications.