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

TL;DR

This paper uses ab initio calculations to explore how electron-phonon coupling strength influences signatures of even and odd-frequency superconductivity in APt3P compounds, predicting experimental markers such as the paramagnetic Meissner effect.

Contribution

It provides a theoretical link between electron-phonon coupling variations and observable signatures of odd-frequency superconductivity in a new material family.

Findings

Dip-hump structures in tunneling spectra vary with coupling strength.

Coexistence of even and odd-frequency superconductivity can be induced by magnetic fields.

Paramagnetic Meissner effect predicted as a hallmark of odd-frequency pairing.

Abstract

The recently discovered APt$_3$P (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 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 experimental identification of bulk odd frequency superconductivity in this material's family.