G. Trambly de Laissardière

Localization of dirac electrons in rotated graphene bilayers.

For Dirac electrons the Klein paradox implies that the confinement is difficult to achieve with an electrostatic potential although it can be of great importance for graphene-based devices. Here, ab initio and tight-binding approaches are combined and show that the wave function of Dirac electrons can be localized in rotated graphene bilayers due to the Moire pattern. This localization of wave function is maximum in the limit of the small rotation angle between the two layers.

Electronic structure and hybridization effects in the compounds Al2Ru and Ga2Ru

Abstract The electronic structure of the compounds Al2Ru and Ga2Ru has been calculated self-consistently by using LMTO-ASA (Linear Muffin Tin Orbitals in the A Atomic Sphere Approximation) method. The calculation strongly indicates that a quasi-semiconductor gap at the Fermi level occurs inside the d states of Ru for both compounds. The models existing in the litterature are discussed and compared to our results and the origin of this quasi-semiconducting behaviour is found to be essentially due to effects of sp (Al,Ga) - d (Ru) hybridization.

Electronic transport properties of quasicrystals

We present a review of some results concerning electronic transport properties of quasicrystals. After a short introduction to the basic concepts of quasiperiodicity, we consider the experimental transport properties of electrical conductivity with particular focus on the effect of temperature, magnetic field, and defects. Then, we present some heuristic approaches that tend to give a coherent view of different, and to some extent complementary, transport mechanisms in quasicrystals. Numerical results are also presented and in particular the evaluation of the linear response Kubo–Greenwood formula of conductivity in quasiperiodic systems in the presence of disorder.

Numerical studies of confined states in rotated bilayers of graphene

Rotated graphene multilayers form a new class of graphene-related systems with electronic properties that drastically depend on the rotation angles. It has been shown that bilayers behave like two isolated graphene planes for large rotation angles. For smaller angles, states in the Dirac cones belonging to the two layers interact resulting in the appearance of two Van Hove singularities. States become localized as the rotation angle decreases and the two Van Hove singularities merge into one peak at the Dirac energy. Here we go further and consider bilayers with very small rotation angles. In this case, well-defined regions of AA stacking exist in the bilayer supercell and we show that states are confined in these regions for energies in the [

Electronic Structure of Transition Atoms in Quasi-Crystals and Hume-Rothery Alloys

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Electronic confinement by clusters in quasicrystals and approximants

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Electronic properties and the role of d states in stable quasicrystals

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Theoretical and experimental electronic distributions in AL6Mn

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Electronic transport in AlMn(Si) and AlCuFe quasicrystals: Break-down of the semiclassical model

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Anderson model for Hume-Rothery alloys containing transition metals

the interplane mean interaction. As a consequence, the local densities of states show discrete peaks for energies different from the Dirac energy.