Electron spin dynamics in strongly correlated metals

TL;DR

This paper investigates the unusual temperature-dependent electron spin properties in strongly correlated alkali fullerides, introducing a new theoretical approach to unify their analysis within the Kubo formalism.

Contribution

It presents a novel concept of 'complex electron spin resonance frequency shift' to analyze spin dynamics in narrow band, strongly correlated metals.

Findings

Explains anomalous temperature dependence of T_1 and g-factor.

Provides a unified theoretical framework for nearly degenerate bands.

Applicable to metals with large momentum scattering and residual values.

Abstract

The temperature dependence of the electron spin life-time, T_1 and the g-factor are anomalous in alkali fullerides (K,Rb)_3C_60, which cannot be explained by the canonical Elliott-Yafet theory. These materials are archetypes of strongly correlated and narrow band metals. We introduce the concept of "complex electron spin resonance frequency shift" to treat these measurables in a unified manner within the Kubo formalism. The theory is applicable for metals with nearly degenerate conduction bands and large momentum scattering even with an anomalous temperature dependence and sizeable residual value.