Recent scattering-type scanning near-field optical spectroscopy (s-SNOM) experiments on single-layer graphene have reported Dirac plasmon lifetimes that are substantially shorter than the dc transport scattering time \tau_{tr}. We highlight that the plasmon lifetime is fundamentally different from \tau_{tr} since it is controlled by the imaginary part of the current-current linear response function at finite momentum and frequency. We first present the minimal theory of the extrinsic lifetime of Dirac plasmons due to scattering against impurities. We then show that a very reasonable concentration of charged impurities yields a plasmon damping rate which is in good agreement with s-SNOM experimental results.
@article{arxiv.1307.7371,
title = {The impact of disorder on Dirac plasmon losses},
author = {Alessandro Principi and Giovanni Vignale and Matteo Carrega and Marco Polini},
journal= {arXiv preprint arXiv:1307.7371},
year = {2013}
}
Comments
5 pages, 2 figures, to be submitted to Phys. Rev. B