Anisotropy of Quasiparticle Lifetimes and the Role of Disorder for Ultrafast Electron Dynamics in Graphite

Gunnar Moos; Cornelius Gahl; Roman Fasel; Martin Wolf; Tobias Hertel

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Anisotropy of Quasiparticle Lifetimes and the Role of Disorder for Ultrafast Electron Dynamics in Graphite

Gunnar Moos·Cornelius Gahl·Roman Fasel·Martin Wolf·Tobias Hertel

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Abstract

Femtosecond time-resolved photoemission of photoexcited electrons in highly oriented pyrolytic graphite (HOPG) provides strong evidence for anisotropies of quasiparticle (QP) lifetimes. Indicative of such anisotropies is a pronounced anomaly in the energy dependence of QP lifetimes between 1.1 eV and 1.5 eV - the vicinity of a saddle point in the graphite bandstructure. This is supported by recent ab initio calculations and a comparison with experiments on defect-enriched HOPG which reveal that disorder, e.g. defects or phonons, increases electron energy relaxation rates.

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Gunnar Moos, Cornelius Gahl, Roman Fasel, Martin Wolf, Tobias Hertel. 2001-06-23. Anisotropy of Quasiparticle Lifetimes and the Role of Disorder for Ultrafast Electron Dynamics in Graphite. https://arxiv.org/abs/cond-mat/0106486

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