The effect of epitaxial strain and doping on electron-phonon coupling and superconducting properties of nitride superconductors from first principles*

Superconducting transition metal nitrides have been identified as an important materials class for low temperature superconducting electronics. The recent epitaxial integration of nitride superconductors with nitride semiconductors, opens new avenues for integrated semiconductor/superconductor devices [Nature 555, 183–189 (2018)], but due to a lattice mismatch, the superconducting material may be strained by several percent. In this work, using first-principles techniques, we explore the effect of strain and doping on the electron-phonon coupling and superconducting transition temperature of superconducting transition metal nitrides.