2008/03/19 by N. M. R. Peres, Tobias Stauber, T. Stauber +1
Materials Science · Physics and Astronomy · #Graphene research and applications #Surface and Thin Film Phenomena #Thermal properties of materials #cond-mat.mes-hall
paper · pdf · doi:10.1209/0295-5075/84/38002
published as EuroPhysics Letters 84, 38002 (2008) · 4 pages, 3 figures
arxiv created 2008/03/19 · openalex publication_date 2008/10/16 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We study the infrared conductivity of graphene at finite chemical potential and temperature taking into account the effect of phonons and disorder due to charged impurities and unitary scatterers, that is, considering all possible single-particle scattering mechanisms. The screening of the long-range Coulomb potential is treated using the random phase approximation coupled to the coherent potential approximation. The effect of the electron-phonon coupling is studied in second-order perturbation theory. The theory has essentially one free parameter, namely, the number of charge impurities per carbon, n C i . Our most important results are the finding of an anomalous enhancement of the conductivity in a frequency region that is blocked by Pauli exclusion, in a picture based on independent electrons, and an impurity broadening of the conductivity threshold, close to twice the chemical potential. We also find that phonons induce Stokes and anti-Stokes lines that produce an excess conductivity, when compared to the far infrared value of σ 0 =(π/2)e 2 / h .