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Journal ArticleDOI

The electronic properties of graphene

TL;DR: In this paper, the basic theoretical aspects of graphene, a one-atom-thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic excitations, are discussed.
Abstract: This article reviews the basic theoretical aspects of graphene, a one-atom-thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic excitations. The Dirac electrons can be controlled by application of external electric and magnetic fields, or by altering sample geometry and/or topology. The Dirac electrons behave in unusual ways in tunneling, confinement, and the integer quantum Hall effect. The electronic properties of graphene stacks are discussed and vary with stacking order and number of layers. Edge (surface) states in graphene depend on the edge termination (zigzag or armchair) and affect the physical properties of nanoribbons. Different types of disorder modify the Dirac equation leading to unusual spectroscopic and transport properties. The effects of electron-electron and electron-phonon interactions in single layer and multilayer graphene are also presented.

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Citations
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Journal ArticleDOI
TL;DR: This work reviews the historical development of Transition metal dichalcogenides, methods for preparing atomically thin layers, their electronic and optical properties, and prospects for future advances in electronics and optoelectronics.
Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

13,348 citations

Journal ArticleDOI
19 Jun 2009-Science
TL;DR: This review analyzes recent trends in graphene research and applications, and attempts to identify future directions in which the field is likely to develop.
Abstract: Graphene is a wonder material with many superlatives to its name. It is the thinnest known material in the universe and the strongest ever measured. Its charge carriers exhibit giant intrinsic mobility, have zero effective mass, and can travel for micrometers without scattering at room temperature. Graphene can sustain current densities six orders of magnitude higher than that of copper, shows record thermal conductivity and stiffness, is impermeable to gases, and reconciles such conflicting qualities as brittleness and ductility. Electron transport in graphene is described by a Dirac-like equation, which allows the investigation of relativistic quantum phenomena in a benchtop experiment. This review analyzes recent trends in graphene research and applications, and attempts to identify future directions in which the field is likely to develop.

12,117 citations

Journal ArticleDOI
TL;DR: Topological superconductors are new states of quantum matter which cannot be adiabatically connected to conventional insulators and semiconductors and are characterized by a full insulating gap in the bulk and gapless edge or surface states which are protected by time reversal symmetry.
Abstract: Topological insulators are new states of quantum matter which cannot be adiabatically connected to conventional insulators and semiconductors. They are characterized by a full insulating gap in the bulk and gapless edge or surface states which are protected by time-reversal symmetry. These topological materials have been theoretically predicted and experimentally observed in a variety of systems, including HgTe quantum wells, BiSb alloys, and Bi2Te3 and Bi2Se3 crystals. Theoretical models, materials properties, and experimental results on two-dimensional and three-dimensional topological insulators are reviewed, and both the topological band theory and the topological field theory are discussed. Topological superconductors have a full pairing gap in the bulk and gapless surface states consisting of Majorana fermions. The theory of topological superconductors is reviewed, in close analogy to the theory of topological insulators.

11,092 citations

Journal ArticleDOI
TL;DR: An overview of the synthesis, properties, and applications of graphene and related materials (primarily, graphite oxide and its colloidal suspensions and materials made from them), from a materials science perspective.
Abstract: There is intense interest in graphene in fields such as physics, chemistry, and materials science, among others. Interest in graphene's exceptional physical properties, chemical tunability, and potential for applications has generated thousands of publications and an accelerating pace of research, making review of such research timely. Here is an overview of the synthesis, properties, and applications of graphene and related materials (primarily, graphite oxide and its colloidal suspensions and materials made from them), from a materials science perspective.

8,919 citations

Journal ArticleDOI
TL;DR: This Review describes how the tunable electronic structure of TMDs makes them attractive for a variety of applications, as well as electrically active materials in opto-electronics.
Abstract: Ultrathin two-dimensional nanosheets of layered transition metal dichalcogenides (TMDs) are fundamentally and technologically intriguing. In contrast to the graphene sheet, they are chemically versatile. Mono- or few-layered TMDs - obtained either through exfoliation of bulk materials or bottom-up syntheses - are direct-gap semiconductors whose bandgap energy, as well as carrier type (n- or p-type), varies between compounds depending on their composition, structure and dimensionality. In this Review, we describe how the tunable electronic structure of TMDs makes them attractive for a variety of applications. They have been investigated as chemically active electrocatalysts for hydrogen evolution and hydrosulfurization, as well as electrically active materials in opto-electronics. Their morphologies and properties are also useful for energy storage applications such as electrodes for Li-ion batteries and supercapacitors.

7,903 citations

References
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Journal ArticleDOI
TL;DR: In this article, an external potential is used to confine quasiparticles in a small region of a graphene strip, where transversal electron motion plays a crucial role in this confinement.
Abstract: We suggest a way of confining quasiparticles by an external potential in a small region of a graphene strip. Transversal electron motion plays a crucial role in this confinement. Properties of thus obtained graphene quantum dots are investigated theoretically for different types of the boundary conditions at the edges of the strip. The (quasi)bound states exist in all systems considered. At the same time, the dependence of the conductance on the gate voltage carries information about the shape of the edges.

281 citations

Journal ArticleDOI
TL;DR: In this paper, cyclotron resonance in monolayer graphene is detected using the photoconductive response of the sample for several different Landau level occupancies, leading to a difference in the electron and hole velocities of 5% by energies of 125 meV away from the Dirac point.
Abstract: We report studies of cyclotron resonance in monolayer graphene. Cyclotron resonance is detected using the photoconductive response of the sample for several different Landau level occupancies. The experiments measure an electron velocity at the K- (Dirac) point of $c_{K}^{*}$ = 1.093 x 10$^{6}$ ms$^{-1}$ and in addition detect a significant asymmetry between the electron and hole bands, leading to a difference in the electron and hole velocities of 5% by energies of 125 meV away from the Dirac point.

268 citations


"The electronic properties of graphe..." refers background in this paper

  • ...The experimental observation of the √ n dependence of the cyclotron mass provides evidence for the existence of massless Dirac quasiparticles in graphene (Deacon et al., 2007; Jiang et al., 2007a; Zhang et al., 2005) - the usual parabolic (Schrödinger) dispersion implies a constant cyclotron mass....

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  • ...A tight binding fit to cyclotron resonance experiments (Deacon et al., 2007) finds t′ ≈ 0....

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Journal ArticleDOI
TL;DR: In this article, the changes in the electronic structure induced by lattice defects in graphene planes were studied and it was shown that lattice distortions give rise to localized states at the Fermi level.
Abstract: We study the changes in the electronic structure induced by lattice defects in graphene planes. In many cases, lattice distortions give rise to localized states at the Fermi level. Electron-electron interactions lead to the existence of local moments. The RKKY interaction between these moments is always ferromagnetic, due to the semimetallic properties of graphene.

267 citations


"The electronic properties of graphe..." refers background or methods in this paper

  • ...The existen e of these states anbe investigated by analyzing the s aling of the spe trumnear a defe t as a fun tion of the size of the system, L(Vozmediano et al., 2005)....

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  • ...The existence of these states can be investigated by analyzing the scaling of the spectrum near a defect as a function of the size of the system, L (Vozmediano et al., 2005)....

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  • ...At half- lling extended de-fe ts lead to an RKKY intera tion with an |r|−3 de-penden e (Dugaev et al., 2006; Vozmediano et al., 2005)....

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  • ...At halffilling extended defects lead to an RKKY interaction with an |r|−3 dependence (Dugaev et al., 2006; Vozmediano et al., 2005)....

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Journal ArticleDOI
TL;DR: Some unusual properties of layered graphite, including a linear energy dependence of the quasiparticle damping and weak ferromagnetism at low doping, are explained as a result of the proximity of a single graphene sheet to the excitonic insulator phase.
Abstract: Some unusual properties of layered graphite, including a linear energy dependence of the quasiparticle damping and weak ferromagnetism at low doping, are explained as a result of the proximity of a single graphene sheet to the excitonic insulator phase which can be further stabilized in a doped system of many layers stacked in the staggered ( $\mathrm{ABAB}\dots{}$) configuration.

263 citations


"The electronic properties of graphe..." refers background in this paper

  • ...Non-perturbative calculations of the effects of the long range interactions in undoped graphene show that a transition to a gapped phase is also possible, when the number of electronic flavors is large (Khveshchenko, 2001; Luk’yanchuk and Kopelevich, 2004)....

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