Minimum Electrical and Thermal Conductivity of Graphene: A Quasiclassical Approach

TL;DR

This paper analyzes the minimum electrical and thermal conductivity of graphene using a quasiclassical approach that incorporates electron-hole coherence, revealing limitations of previous Boltzmann-based models in low-mobility samples.

Contribution

It introduces a quasiclassical method accounting for electron-hole coherence effects in graphene's conductivity, extending understanding beyond traditional Boltzmann equation models.

Findings

Derived analytical solutions for conductivity considering coherence effects

Confirmed Wiedemann-Franz law holds in the studied regime

Identified limitations of previous models for low-mobility samples

Abstract

We investigate the minimum conductivity of graphene within a quasiclassical approach taking into account electron-hole coherence effects which stem from the chiral nature of low energy excitations. Relying on an analytical solution of the kinetic equation in the electron-hole coherent and incoherent cases we study both the electrical and thermal conductivity whose relation fullfills Wiedemann-Franz law. We found that the most of the previous findings based on the Boltzmann equation are restricted to only high mobility samples where electron-hole coherence effects are not sufficient.