COEXISTENCE OF SUPERCONDUCTIVITY AND ANTIFERROMAGNETISM

An overview of the theoretical work on the problem of the influence of the antiferromagnetic ordering of localized spins on the superconducting state is provided. Effects of the exchange interaction of electrons with localized spins, are investigated. Separate treatment is given to the electron-magnon part of this interaction. The electron-magnon contribution is shown to affect both the singlet and triplet pairings. For different antiferromagnets - a collinear antiferromagnetic structure and a simple spiral structure - we investigate in detail the effect of the electron spectrum exchange readjustment due to the magnetic structure and analyse the relation of this effect to superconductivity. The influence of nonmagnetic impurities on the superconducting transition temperature in antiferromagnets is also noted. The entire treatment is carried out in terms of a unified approach of strong-coupling theory, by invoking the use of Eliashberg equations.