Influence of electron–phonon coupling strength on signatures of even and odd-frequency superconductivity

The recently discovered APt₃P (A=Sr,Ca,La) family of superconductors offers a platform to study frequency dependent superconducting phenomena as the electron–phonon coupling varies from weak to strong. Here we perform ab initio Eliashberg theory calculations to investigate two such phenomena, the occurrence of dip-hump structures in the tunneling spectra and the magnetic field induced coexistence of even and odd frequency superconductivity in these compounds. By calculating the superfluid density, we make materials specific predictions for the occurrence of the paramagnetic Meissner effect as a hallmark of odd frequency pairing. Our results provide a link between two seemingly uncorrelated aspects of even and odd frequency superconductivity and provide theoretical guidance for the future experimental identification of bulk odd frequency superconductivity in this materials’ family.