Finite temperature inelastic mean free path and quasiparticle lifetime in graphene

TL;DR

This paper investigates how finite temperature affects the inelastic mean free path and quasiparticle lifetime in graphene using many-body approximations, revealing significant temperature-dependent effects and comparing electron-electron and electron-phonon interactions.

Contribution

It provides a detailed analysis of temperature corrections to inelastic scattering in graphene, including both electron-electron and electron-phonon interactions, and compares these effects with conventional 2D systems.

Findings

Finite temperature significantly reduces the inelastic mean free path in graphene.

Electron-phonon interactions contribute notably only at higher temperatures.

Comparison shows differences between graphene's linear dispersion and parabolic 2D systems.

Abstract

We adopt the GW approximation and random phase approximation to study finite temperature effects on the inelastic mean free path and quasiparticle lifetime by directly calculating the imaginary part of the finite temperature self-energy induced by electron-electron interaction in extrinsic and intrinsic graphene. In particular, we provide the density-dependent leading order temperature correction to the inelastic scattering rate for both single-layer and double-layer graphene systems. We find that the inelastic mean free path is strongly influenced by finite-temperature effects. We present the similarity and the difference between graphene with linear chiral band dispersion and conventional two dimensional electron systems with parabolic band dispersion. We also compare the calculated finite temperature inelastic scattering length with the elastic scattering length due to Coulomb disorder, and comment on the prospects for quantum interference effects showing up in low density graphene transport. We also carry out inelastic scattering calculation for electron-phonon interaction, which by itself gives rather long carrier mean free paths and lifetimes since the deformation potential coupling is weak in graphene, and therefore electron-phonon interaction contributes significantly to the inelastic scattering only at relatively high temperatures.