Effective-Medium Theory for the Normal State in Orientationally Disordered Fullerides

TL;DR

This paper develops an effective-medium theory using a cluster-Bethe-lattice approach to analyze the electronic structure and normal-state properties of orientationally disordered A3C60 fullerides, aligning well with numerical and experimental data.

Contribution

It introduces a novel cluster-Bethe-lattice method to model disordered fullerides, enabling accurate calculations of electronic properties and conductivity.

Findings

The theory accurately predicts electronic structure features.

Calculated conductivity matches experimental measurements.

Model aligns with numerical simulations of disordered lattices.

Abstract

An effective-medium theory for studying the electronic structure of the orientationally disordered A3C60 fullerides is developed and applied to study various normal-state properties. The theory is based on a cluster-Bethe-lattice method in which the disordered medium is modelled by a three-band Bethe lattice, into which we embed a molecular cluster whose scattering properties are treated exactly. Various single-particle properties and the frequency-dependent conductivity are calculated in this model, and comparison is made with numerical calculations for disordered lattices, and with experiment.