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arXiv · 1301.6108

Observation of suppressed terahertz absorption in photoexcited graphene

A. J. Frenzel·C. H. Lui·W. Fang·N. L. Nair·P. K. Herring·P. Jarillo-Herrero·J. Kong·N. Gedik
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Abstract

When light is absorbed by a semiconductor, photoexcited charge carriers enhance the absorption of far-infrared radiation due to intraband transitions. We observe the opposite behavior in monolayer graphene, a zero-gap semiconductor with linear dispersion. By using time domain terahertz (THz) spectroscopy in conjunction with optical pump excitation, we observe a reduced absorption of THz radiation in photoexcited graphene. The measured spectral shape of the differential optical conductivity exhibits non-Drude behavior. We discuss several possible mechanisms that contribute to the observed low-frequency non-equilibrium optical response of graphene.

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A. J. Frenzel, C. H. Lui, W. Fang, N. L. Nair, P. K. Herring, P. Jarillo-Herrero, J. Kong, N. Gedik. 2013-03-30. Observation of suppressed terahertz absorption in photoexcited graphene. https://doi.org/10.1063/1.4795858

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