Minimum electrical and thermal conductivity of graphene: a quasiclassical approach

Phys Rev Lett. 2007 Nov 23;99(21):216602. doi: 10.1103/PhysRevLett.99.216602. Epub 2007 Nov 21.

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 the thermal conductivity whose relation satisfies the Wiedemann-Franz law. We find that 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.