Competing Superconducting States in Strong Ferromagnets

TL;DR

This paper investigates the competition between exotic triplet pair density wave superconductivity and conventional superconductivity in strongly polarized media, proposing experimental identification methods and potential realizations in heterostructures.

Contribution

It provides a systematic analysis of PDW states in ferromagnetic systems and suggests experimental setups for their detection.

Findings

Only one PDW state may dominate or coexist with homogeneous SC.

Proposes experimental identification of PDW SC in ferromagnetic heterostructures.

Indicates possible emergence of exotic states in half-metallic and strongly ferromagnetic superconductors.

Abstract

We report results from a systematic study of the competition of exotic triplet pair density wave (PDW) superconductivity (SC) with homogeneous (zero pair momentum) SC in strongly polarized media such as half metallic systems. From the two different PDW states allowed by symmetry in this background only one may dominate or even coexist with homogeneous SC. We propose a direct experimental identification of PDW SC in this context. Our results suggest that these exotic states may plausibly emerge in heterostructures involving proximity of SC with half-metallic CrO$_2$ where induced SC is established in the half metallic region and in strongly ferromagnetic superconductors.