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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 paper, the authors compute the electrical and thermal conductivities and Hall conductivities of the DDW state in the low-temperature impurity-scattering-dominated regime for low-dopings, at which they are dominated by nodal quasiparticles.
Abstract: We compute the electrical and thermal conductivities and Hall conductivities of the $d$-density wave (DDW) state in the low-temperature impurity-scattering-dominated regime for low-dopings, at which they are dominated by nodal quasiparticles We show that the longitudinal conductivity in this limit in the DDW state is not Drude-like However, the thermal conductivty is Drude-like; this is a reflection of the discrepancy between electrical and thermal transport at finite frequency in the DDW state An extreme example of this occurs in the $\mu=0$, $\tau\to\infty$ limit, where there is a strong violation of the Wiedemann-Franz law: ${\kappa_{xx}}/{\sigma_{xx}} \propto {T^2}$ at $\omega=0$ and ${\kappa_{xx}}/{\sigma_{xx}}=0$ at finite frequency The DDW electrical and thermal Hall conductivities are linear in the magnetic field, $B$, for weak fields The formation of Landau levels at the nodes leads to the quantization of these Hall conductivities at high fields In all of these ways, the quasiparticles of the DDW state differ from those of the $d_{{x^2}-{y^2}}$ superconducting (DSC) state

45 citations

Journal ArticleDOI
TL;DR: The magnetoreflection experiment indicates considerable warping of the Fermi surface, particularly for holes, and the band parameters of the Slonczewski-Weiss model have been evaluated and the Fermani surface determined.
Abstract: Recent magnetoreflection measurements in pyrolytic graphite have been interpreted using the magnetic energy levels obtained from the McClure-lnoue secular equation and the appropriate selection rules for interband transitions. Combining these results with those of the de Haas - van Alphen effect, the band parameters of the Slonczewski-Weiss model have been evaluated and the Fermi surface determined. The magnetoreflection experiment indicates considerable warping of the Fermi surface, particularly for holes. Further experiments to determine this warping more precisely are discussed.

44 citations


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

  • ...The values ofthese parameters, and their dependen e with pressure,or, equivalently, the interatomi distan es, have been ex-tensively studied (Brandt et al., 1988; Dillon et al., 1977;Dresselhaus and Mavroides, 1964; M Clure, 1957, 1964;Nozières, 1958; Soule et al., 1964)....

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Journal ArticleDOI

44 citations


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

  • ...5 eV (Baeriswyl et al., 1986)....

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  • ...For omparison purposes, in polya etylenethe value for the Hubbard intera tion is U ≃10 eV andthe hopping energy is t ≈ 2.5 eV (Baeriswyl et al., 1986)....

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Journal ArticleDOI
TL;DR: In this article, the interplay of Klein tunneling between $n$-doped and $p$doped regions in graphene and Andreev reflection at a superconducting electrode was studied.
Abstract: We study the interplay of Klein tunneling ($=\text{interband}$ tunneling) between $n$-doped and $p$-doped regions in graphene and Andreev reflection ($=\text{electron}$-hole conversion) at a superconducting electrode. The tunneling conductance of an $n\text{\ensuremath{-}}p\text{\ensuremath{-}}n$ junction initially increases upon lowering the temperature, while the coherence time of the electron-hole pairs is still less than their lifetime, but then drops back again when the coherence time exceeds the lifetime. This reentrance effect, known from diffusive conductors and ballistic quantum dots, provides a method to detect phase coherent Klein tunneling of electron-hole pairs.

42 citations


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

  • ...…(Cheianov et al.,2007a; Cheianov and Fal'ko, 2006; Fogler et al., 2007a;Huard et al., 2007; Lemme et al., 2007; Tworzydlo et al.,2007; Williams et al., 2007; Zhang and Fogler, 2007) andp-n-p (Ossipov et al., 2007) jun tions, and as neutrino billiards (Berry and Modragon, 1987; Miao et al., 2007)....

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