Broadband electromagnetic response and ultrafast dynamics of few-layer epitaxial graphene

Choi, H.; Borondics, F.; Siegel, D. A.; Zhou, S. Y.; Martin, M. C.; Lanzara, A.; Kaindl, R. A.

Broadband electromagnetic response and ultrafast dynamics of few-layer epitaxial graphene

Authors

Description

We study the broadband optical conductivity and ultrafast carrier dynamics of epitaxial graphene in the few-layer limit. Equilibrium spectra of nominally buffer, monolayer, and multilayer graphene exhibit significant terahertz and near-infrared absorption, consistent with a model of intra- and interband transitions in a dense Dirac electron plasma. Non-equilibrium terahertz transmission changes after photoexcitation are shown to be dominated by excess hole carriers, with a 1.2-ps mono-exponential decay that reflects the minority-carrier recombination time.
4 pages, 3 figures, final version