Quantifying Proximity-Induced Superconductivity from First-Principles Calculations

Proximity-induced superconductivity with a clean interface has attracted much attention in recent years. We discuss how the commonly employed electron tunneling approximation can be hybridized with first-principles calculation to achieve a semi-quantitative characterization starting from the microscopic atomic structure. By using the graphene-Zn heterostructure as an example, we compare this approximated treatment to the full ab initio anisotropic Eliashberg formalism. Based on the calculation results, we show that interfacial effects beyond the electron tunneling approximation are noticeable even in a rather weakly coupled heterojunction.