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arXiv · 1410.7499

Ultrafast THz Faraday Rotation in Graphene

J. N. Heyman·R. F. Foo Kune·B. A. Alebachew·M. D. Nguyen·J. T. Robinson
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Abstract

Terahertz (THz) Faraday rotation measurements were performed to investigate carrier dynamics in p-type CVD graphene. We used static and time-resolved polarization-sensitive THz transmission measurements in a magnetic field to probe free carriers in GaAs, InP and Graphene. Static measurements probe the equilibrium carrier density and momentum scattering rate. Time-resolved (optical pump/THz probe) measurements probe the change in these quantities following photoexcitation. In a typical CVD graphene sample we found that 0.5ps following photoexcitation with 1*10^13 photons/cm2 pulses at 800nm the effective hole scattering time decreased from 37fs to 34.5fs, while the carrier concentration increased from 2.0*10^12/cm2 to 2.04*10^12/cm2, leading to a transient decrease in the conductivity of the film.

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J. N. Heyman, R. F. Foo Kune, B. A. Alebachew, M. D. Nguyen, J. T. Robinson. 2014-10-28. Ultrafast THz Faraday Rotation in Graphene. https://doi.org/10.1063/1.4903212

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