Electronic properties of graphene multilayers

TL;DR

This paper investigates how disorder affects the electronic properties of graphene multilayers, revealing non-Fermi liquid behavior, a universal minimum in in-plane conductivity, and enhanced c-axis conductivity at low doping.

Contribution

It provides a detailed analysis of disorder effects in multilayer graphene, highlighting unique transport phenomena and deviations from traditional Fermi liquid theory.

Findings

Density of states diverges near half-filling.

In-plane conductivity has a universal minimum value.

Disorder enhances c-axis conductivity at low doping.

Abstract

We study the effects of disorder in the electronic properties of graphene multilayers, with special focus on the bilayer and the infinite stack. At low energies and long wavelengths, the electronic self-energies and density of states exhibit behavior with divergences near half-filling. As a consequence, the spectral functions and conductivities do not follow Landau's Fermi liquid theory. In particular, we show that the quasiparticle decay rate has a minimum as a function of energy, there is a universal minimum value for the in-plane conductivity of order e^2/h per plane and, unexpectedly, the c-axis conductivity is enhanced by disorder at low doping, leading to an enormous conductivity anisotropy at low temperatures.