Drude Conductivity of Dirac Fermions in Graphene

By Jason Horng, Chi-Fan Chen, Baisong Geng, Ç. Girit, Yuanbo Zhang, Z. Hao, H. Bechtel, Michael C. Martin, A. Zettl, M. Crommie and 3 more. 2010

485 citations recorded by the source corpus.

Abstract : Electrons moving in graphene behave as massless Dirac fermions, and they exhibit fascinating low-frequency electrical transport phenomena. Their dynamic response, however, is little known at frequencies above one terahertz (THz). Such knowledge is important not only for a deeper understanding of the Dirac electron quantum transport, but also for graphene applications in ultrahigh speed THz electronics and IR optoelectronics. In this paper, we report the first measurement of high-frequency conductivity of graphene from THz to mid-IR at different carrier concentrations. The conductivity exhibits Drude-like frequency dependence and increases dramatically at THz frequencies, but its absolute strength is substantially lower than theoretical predictions. This anomalous reduction of free electron oscillator strength is corroborated by corresponding changes in graphene interband transitions, as required by the sum rule. Our surprising observation indicates that many-body effects and Dirac fermion-impurity interactions beyond current transport theories are important for Dirac fermion electrical response in graphene.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/2c8dabea6fbfb896267bc74581749163923b3525

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In Atomic and Molecular Physics, and Optics

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Citations in the corpus

Transport in inhomogeneous quantum critical fluids and in the Dirac fluid in graphene (2015, background): “Previous experiments which measured the ac conductivity [76] were not in the hydrodynamic limit.”
Graphene-based Plasmonic Nano-Antenna for Terahertz Band Communication in Nanonetworks (2013, unknown): “In accordance to its conductivity, the propagation of Surface Plasmon Polariton (SPP) waves on doped graphene has been recently analytically studied and experimentally proved [6], [16], [19], [20], [24], [26], [33], [37].”
Strong plasmonic enhancement of photovoltage in graphene. (2011, methodology): “We note that light interference in SiO 2 can provide some dependence of the photovoltage on the wavelength of the excited light, and can be used to enhance the signal even furthe”
Production and processing of graphene and related materials (2020, background): “THz-TDS is based on the fact that the absorption in the THz range is highly dependent on the complexvalued and frequency-dependent electrical conductivity [1644].”
Colloquium: Graphene spectroscopy (2014, background): “At the same time, the optical sum rule ∫∞ 0 σ′(ω)dω = const was apparently obeyed (Horng et al., 2011).”