Superconducting states in ferromagnetic metals

TL;DR

This paper explores the symmetry, domain structure, and interplay of ferromagnetism and superconductivity in ferromagnetic metals with cubic and orthorhombic crystal symmetries, highlighting the conditions for superconducting states and their spectral features.

Contribution

It provides a theoretical analysis of superconducting states emerging from ferromagnetic order, including symmetry considerations, domain structures, and the effects of magnetic interactions.

Findings

Superconducting states have specific symmetry nodes in quasiparticle spectra.

Superconducting phase transition involves formation of domain structures with complex conjugate states.

Ferromagnetic moments stimulate nonunitary superconducting states while diamagnetic currents suppress superconductivity.

Abstract

The symmetry of the superconducting states arising directly from ferromagnetic states in the crystals with cubic and orthorombic symmetries is described. The symmetry nodes in the quasiparticle spectra of such the states are pointed out if they exist. The superconducting phase transition in the ferromagnet is accompanied by the formation of superconducting domain structure consisting of complex conjugate states imposed on the ferromagnet domain structure with the opposite direction of the magnetization in the adjacent domains. The interplay between stimulation of a nonunitary superconducting state by the ferromagnetic moment and supression of the superconductivity by the diamagnetic orbital currents is established.