Theory of ferromagnetic unconventional superconductors with spin-triplet electron pairing

TL;DR

This paper develops a phenomenological theory for ferromagnetic superconductors with spin-triplet pairing, explaining their phase diagrams, quantum transitions, and classifying them into two types based on experimental data.

Contribution

It introduces a comprehensive phenomenological framework for understanding ferromagnetic superconductors with spin-triplet pairing, including phase diagrams and classification criteria.

Findings

Detailed temperature-pressure phase diagrams for real compounds

Classification of ferromagnetic superconductors into two types

Analysis of quantum phase transitions in these systems

Abstract

A general phenomenological theory is presented for the phase behavior of ferromagnetic superconductors with spin-triplet electron Cooper pairing. The theory describes in details the temperature-pressure phase diagrams of real inter-metallic compounds exhibiting the remarkable phenomenon of coexistence of spontaneous magnetic moment of the itinerant electrons and spin-triplet superconductivity. The quantum phase transitions which may occur in these systems are also described. The theory allows for a classification of these itinerant ferromagnetic superconductors in two types: type I and type II. The classification is based on quantitative criteria.The comparison of theory and experiment is performed and outstanding problems are discussed.