Title :
Ultrafast terahertz studies of dirac fermion dynamics in graphene
Author :
Choi, Hyunyong ; Borondics, Ferenc ; Siegel, David A. ; Zhou, Shuyun ; Martin, Michael C. ; Lanzara, Alessandra ; Kaindl, Robert A.
Author_Institution :
Mater. Sci. Div., Lawrence Berkeley Nat. Lab., Berkeley, CA, USA
Abstract :
We report the broadband optical conductivity and ultrafast carrier dynamics of few-layer graphene. Equilibrium spectra exhibit significant THz and near-IR absorption, consistent with a model of intra- and interband transitions in a dense Dirac electron plasma. Ultrafast THz transmission changes after photoexcitation are dominated by excess holes, with a 1.2-ps exponential decay that reflects minority-carrier recombination.
Keywords :
fermion systems; graphene; high-speed optical techniques; infrared spectra; minority carriers; optical conductivity; photoexcitation; terahertz wave spectra; C; Dirac Fermion dynamics; broadband optical conductivity; dense Dirac electron plasma; equilibrium spectra; graphene; interband transition; intraband transition; minority-carrier recombination; photoexcitation; time 1.2 ps; ultrafast carrier dynamics; ultrafast terahertz study; Absorption; Conductivity; Electron optics; Laboratories; Nonhomogeneous media; Nonlinear optics; Optical buffering; Optical scattering; Spectroscopy; Ultrafast optics;
Conference_Titel :
Infrared, Millimeter, and Terahertz Waves, 2009. IRMMW-THz 2009. 34th International Conference on
Conference_Location :
Busan
Print_ISBN :
978-1-4244-5416-7
Electronic_ISBN :
978-1-4244-5417-4
DOI :
10.1109/ICIMW.2009.5324954
