Electron effective mass in graphene

Ariel, Viktor; Natan, Amir

doi:10.1109/iceaa.2013.6632334

Cited by 28 publications

(17 citation statements)

References 7 publications

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“…These parameters are listed in Table 1. For the 5QL-slabs, the effective mass of electron was estimated by fitting the linear dispersion curve of the lowest conduction band with the relationship m ¼ _k vF , where ν F is the Fermi velocity, 46 while total surface carrier concentration was obtained by integrating the occupied surface states charge below Fermi energy level (the region Kʹ-Mʹ, see Supplementary Figures 7 and 8). Note that the predicted carrier densities are systematically higher than those derived from electrical and optical measurements, since we consider all the intrinsic surface charge carriers of TI materials, which in actual experiments could undergo several scattering pathways (for example, charge carrier-optical phonon scattering or charge carrier-surface scattering).…”

Section: Plasmonics Of Tis At Optical Frequencies J Yin Et Almentioning

confidence: 99%

Plasmonics of topological insulators at optical frequencies

et al. 2017

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The development of nanoplasmonic devices, such as plasmonic circuits and metamaterial superlenses in the visible to ultraviolet frequency range, is hampered by the lack of low-loss plasmonic media. Recently, strong plasmonic response was reported in a certain class of topological insulators. Here, we present a first-principles density functional theory analysis of the dielectric functions of topologically insulating quaternary (Bi,Sb) 2 (Te,Se) 3 trichalcogenide compounds. Bulk plasmonic properties, dominated by interband transitions, are observed from 2 to 3 eV and extend to higher frequencies. Moreover, trichalcogenide compounds are better plasmonic media than gold and silver at blue and UV wavelengths. By analyzing thin slabs, we also show that these materials exhibit topologically protected surface states, which are capable of supporting propagating plasmon polariton modes over an extremely broad spectral range, from the visible to the mid-infrared and beyond, owing to a combination of interand intra-surface band transitions. NPG Asia Materials (2017) 9, e425; doi:10.1038/am.2017.149; published online 25 August 2017 INTRODUCTIONThe fields of metamaterials and plasmonics have seen an extraordinary evolution in recent years, from the initial theoretical predictions of artificial negative refractive indices and cloaking 1,2 to the experimental realization of photonic metadevices with various functionalities that can be engineered and obtained on demand. 3,4 However, the practical implementations of plasmonic and metamaterial devices have long been hampered by energy dissipation in plasmonic media, especially in the visible to ultraviolet (UV) range, where even the best plasmonic metals (such as gold, silver and aluminum) suffer from strong dissipation due to interband electronic transitions and Drude losses. 5 This has inspired a search for alternative low-loss plasmonic materials for optical devices operating at high frequencies. 6,7 Candidates that are currently being investigated include highly doped semiconductors, metallic alloys, nitrides and oxides 8 and, more recently, twodimensional materials and topological insulator (TI) materials.TIs represent a new quantum phase of matter, which originates from the topological character of the bulk electronic bands in certain materials. The strong spin-orbit coupling in such materials leads to a band inversion and the appearance of Dirac surface states in the band gap. These topological surface states are chiral and protected from back-scattering by time-reversal symmetry. As a consequence, charge carriers from topologically protected surface states can carry current and are free to move parallel to the surface. Thus, TIs are ideal candidates to realize exotic plasmonic phenomena. Localized plasmons have recently been observed in TIs at THz frequencies (in Bi 2 Se 3 ) 9,10 as well as visible-to-UV frequencies (in single crystal

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Section: Plasmonics Of Tis At Optical Frequencies J Yin Et Almentioning

confidence: 99%

Plasmonics of topological insulators at optical frequencies

et al. 2017

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“…These parameters are listed in Table 1. For the 5QL-slabs, the effective mass of electron was estimated by fitting the linear dispersion curve of the lowest conduction band with the relationship = ℏ , where is the Fermi velocity, 48 while the total surface carrier concentration was obtained by integrating the occupied surface states charge below Fermi energy level (the region Kʹ-Mʹ, see Supplementary Figs 7-8). The intraband surface contribution to the dielectric response was determined using the methodology developed for other two-dimensional systems, such as graphene.…”

Section: Resultsmentioning

confidence: 99%

Plasmonics of topological insulators at optical frequencies

Yin¹,

Krishnamoorthy²,

Adamo³

et al. 2017

2017 Conference on Lasers and Electro-Optics Europe &Amp; European Quantum Electronics Conference (CLEO/Europe-EQEC)

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“…The transverse mass is closely related to the cyclotron mass, which is the reason why the latter definition works for graphene. 13 In a magnetic field, charged particles move in circles with centripetal force and acceleration perpendicular to the velocity. The cyclotron mass is the ratio of force to acceleration when they are both perpendicular to the momentum (velocity) direction, which is exactly the case for the transverse mass as discussed above.…”

Section: Derivationsmentioning

confidence: 99%

“…Pedagogical descriptions that try to avoid the relativistic / Dirac explanation often rely on alternate definitions arXiv:1806.10027v2 [cond-mat.mes-hall] 19 Jan 2019 of the mass that work correctly for graphene e.g. cyclotron effective mass 13,14 , quarternion effective mass 15 etc. While these definitions work for a reason, as we will discuss below, they do not provide an intuitive picture of how electrons in graphene conduct remarkably well.…”

Section: Introductionmentioning

confidence: 99%

Electron mobility in graphene without invoking the Dirac equation

Ullal

Shi

Sundararaman

2019

American Journal of Physics

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The Dirac point and linear band structure in Graphene bestow it with remarkable electronic and optical properties, a subject of intense ongoing research. Explanations of high electronic mobility in graphene, often invoke the masslessness of electrons based on the effective relativistic Diracequation behavior, which are inaccessible to most undergraduate students and are not intuitive for non-physics researchers unfamiliar with relativity. Here, we show how to use only basic concepts from semiconductor theory and the linear band structure of graphene to explain its unusual effective mass and mobility, and compare them with conventional metals and semiconductors. We discuss the more intuitive concept of transverse effective mass that emerges naturally from these basic derivations, which approaches zero in the limit of undoped graphene at low temperature and is responsible for its extremely high mobility.

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Electron effective mass in graphene

Cited by 28 publications

References 7 publications

Plasmonics of topological insulators at optical frequencies

Plasmonics of topological insulators at optical frequencies

Plasmonics of topological insulators at optical frequencies

Electron mobility in graphene without invoking the Dirac equation

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