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dc.contributor.authorRengel Estévez, Raúl 
dc.contributor.authorMartín Martínez, María Jesús
dc.identifier.citationRengel Estévez, R., and Martín Martínez, M.J. (2013). Diffusion coefficient, correlation function, and power spectral density of velocity fluctuations in monolayer graphene. J. Appl. Phys. 114, 143702.es_ES
dc.description.abstractIn this paper, the diffusivity in suspended monolayer graphene at low and high electric fields is investigated. The knowledge of this quantity and its dependence on the electric field is of primary importance not only for the investigation of the electronic transport properties of this material, but also for the development of accurate drift-diffusion models. The results have been obtained by means of an ensemble Monte Carlo simulation. For the calculation of the diffusion coefficient, two different methods are considered, one based on the second central moment and the other one based on the Fourier analysis of velocity fluctuations, which are directly related to the noise behaviour at high frequencies. The diffusion coefficient is analyzed considering both parallel and transversal directions with regard to the applied field. Taking into account the importance of degeneracy in this material, the calculations are properly performed by considering an excess electron population obeying a linearized Boltzmann transport equation, which allows studying in an adequate fashion the diffusivity phenomena. The results show the importance of degeneracy effects at very low fields, in which transport is mainly dominated by acoustic phonon scattering. Values of the diffusion coefficient larger than 40.000 cm2/Vs are obtained for a carrier concentration equal to 10^12 cm-2. The correlation function of instantaneous velocity fluctuation is explained in terms of the wavevector distribution, and their power spectral density is evaluated in the THz range, showing an important dependence on the applied field and being strongly related to microscopic transport processes.es_ES
dc.description.sponsorshipThis work has been supported by research project SA188A11 from the Consejería de Educación de la Junta de Castilla y León.es_ES
dc.publisherAIP Publishinges_ES
dc.rightsAttribution-NonCommercial-NoDerivs 3.0 Unported
dc.subjectDiffusion coefficientes_ES
dc.subjectMonte Carlo methodes_ES
dc.subjectVelocity fluctuationses_ES
dc.titleDiffusion coefficient, correlation function, and power spectral density of velocity fluctuations in monolayer graphenees_ES
dc.subject.unesco2203 Electrónicaes_ES
dc.subject.unesco2203.06 Transporte de electroneses_ES

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Attribution-NonCommercial-NoDerivs 3.0 Unported
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivs 3.0 Unported