Background for the Self Consistent Renormalisation (SCR) Theory

TL;DR

This paper reviews the development of the SCR theory for itinerant magnetism, highlighting its improvements over Stoner and RPA theories by incorporating correlation effects to better explain magnetic phenomena.

Contribution

It provides a comprehensive background on SCR theory, explaining its mathematical framework and how it addresses limitations of previous theories in itinerant magnetism.

Findings

SCR theory successfully explains weakly and nearly ferromagnetic and antiferromagnetic materials.

It improves upon Stoner and RPA theories by including correlation effects.

The mathematical complexity of SCR is discussed in detail.

Abstract

A detailed review is given on the evolution of the theory of itinerant magnetism. The self-consistent renormalization (SCR) theory is quite successful in addressing the phenomenon of itinerant magnetism in weakly and nearly ferromagnetic and anti-ferromagnetic materials. It goes beyond the Stoner and random phase approximation (RPA) theories in taking the correlation effects into account. The Mathematical machinery of the SCR theory is rather complicated. The aim of these notes is to provide the required background. The problems with Stoner and RPA theory are discussed and the way in which the SCR theory rectifies those problems is also discussed.