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Unitary limit for model point scatterers in graphene is known to reveal low-energy resonances. The same limit could be achieved from hybridization of band electrons with the localized impurity level positioned in the vicinity of the Fermi…

Mesoscale and Nanoscale Physics · Physics 2013-04-18 V. V. Mkhitaryan , E. G. Mishchenko

We study Anderson localization in graphene with short-range disorder using the real-space Kubo-Greenwood method implemented on graphics processing units. Two models of short-range disorder, namely, the Anderson on-site disorder model and…

Mesoscale and Nanoscale Physics · Physics 2014-07-01 Zheyong Fan , Andreas Uppstu , Ari Harju

We report on a numerical study of quantum transport in disordered two dimensional graphene and graphene nanoribbons. By using the Kubo and the Landauer approaches, transport length scales in the diffusive (mean free path, charge mobilities)…

Mesoscale and Nanoscale Physics · Physics 2011-05-17 Aurelien Lherbier , Blanca Biel , Yann-Michel Niquet , Stephan Roche

We study the electron scattering produced by local out-of-plane strain deformations in the form of Gaussian bumps in graphene. Of special interest is to take into account the scalar field associated with the redistribution of charge due to…

Mesoscale and Nanoscale Physics · Physics 2018-10-30 Ramon Carrillo-Bastos , Marysol Ochoa , Saúl A. Zavala , Francisco Mireles

We study the spatial structure of wave functions with exceptionally high local amplitudes in the Anderson model of localisation. By means of exact diagonalisations of finite systems, we obtain and analyse images of these wave functions: we…

Disordered Systems and Neural Networks · Physics 2009-11-07 V. Uski , B. Mehlig , M. Schreiber

The wave equation describing the interaction of two electrons in graphene at arbitrary value of the Fermi energy $E_F$ is derived. For the solutions of this equation, we have found the explicit forms of the density and the current which…

Mesoscale and Nanoscale Physics · Physics 2019-02-22 A. I. Milstein , I. S. Terekhov

We demonstrate Anderson localisation of visible light on a chip and report quality factors exceeding highly engineered two-dimensional cavities. Our results reverse the trend, observed so far, of the quality of disorder-induced light…

Optics · Physics 2016-06-15 Tom Crane , Oliver J. Trojak , Luca Sapienza

We study transport length scales in carbon nanotubes and graphene ribbons under the influence of Anderson disorder. We present generalized analytical expressions for the density of states, the elastic mean free path and the localization…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Norbert Nemec , Klaus Richter , Gianaurelio Cuniberti

Combining the tight-binding approximation and linear elasticity theory for a planar membrane, we investigate stretching of a graphene flake assuming that two opposite edges of the sample are clamped by the contacts. We show that, depending…

Mesoscale and Nanoscale Physics · Physics 2012-07-10 M. Mucha-Kruczynski , V. I. Fal'ko

We study the critical behaviour of Anderson localized modes near intersecting flat and dispersive bands in the quasi-one-dimensional diamond ladder with weak diagonal disorder $W$. The localization length $\xi$ of the flat band states…

Disordered Systems and Neural Networks · Physics 2013-12-23 Daniel Leykam , Sergej Flach , Omri Bahat-Treidel , Anton S. Desyatnikov

Band gap engineering in graphene may open the routes towards transistor devices in which electric current can be switched off and on at will. One may, however, ask if a semiconducting band gap alone is sufficient to quench the current in…

Mesoscale and Nanoscale Physics · Physics 2012-11-12 G. Tkachov , Martina Hentschel

Mechanically exfoliated graphene layers deposited on SiO2 substrate were irradiated with Ar+ ions in order to experimentally study the effect of atomic scale defects and disorder on the low-energy electronic structure of graphene. The…

Mesoscale and Nanoscale Physics · Physics 2009-01-21 Levente Tapaszto , Gergely Dobrik , Peter Nemes-Incze , Gabor Vertesy , Philippe Lambin , Laszlo P Biro

We investigate the contribution of charge puddles to the non-vanishing conductivity minimum in disordered graphene flakes at the charge neutrality point. For that purpose, we study systems with a geometry that suppresses the transmission…

Mesoscale and Nanoscale Physics · Physics 2016-01-13 Leandro R. F. Lima , Caio H. Lewenkopf

We study the DC conductivity of a weakly disordered 2D electron gas with two bands and spectral nodes, employing the field theoretical version of the Kubo--Greenwood conductivity formula. Disorder scattering is treated within the standard…

Mesoscale and Nanoscale Physics · Physics 2016-06-09 Andreas Sinner , Klaus Ziegler

Graphene nanoflakes are interesting because electrons are naturally confined in these quasi-zero-dimensional structures, whereas confinement in bulk graphene would require a band gap. Vacancies inside the graphene lattice lead to localized…

Mesoscale and Nanoscale Physics · Physics 2015-04-06 Matthias Droth , Guido Burkard

Effects of disorder and valley polarization in graphene are investigated in the quantum Hall regime. We find anomalous localization properties for the lowest Landau level (LL), where disorder can induce wavefunction delocalization (instead…

Mesoscale and Nanoscale Physics · Physics 2008-02-21 Ana L. C. Pereira , P. A. Schulz

We report on the impact of variable-scale disorder on 3D Anderson localization of a non-interacting ultracold atomic gas. A spin-polarized gas of fermionic atoms is localized by allowing it to expand in an optical speckle potential. Using a…

Quantum Gases · Physics 2015-06-16 W. R. McGehee , S. S. Kondov , W. Xu , J. J. Zirbel , B. DeMarco

Deformations in graphene systems are central elements in the novel field of {\it straintronics}. Various strain geometries have been proposed to produce specific properties but their experimental realization has been limited. Because…

Mesoscale and Nanoscale Physics · Physics 2016-09-20 R. Carrillo-Bastos , C. León , D. Faria , A. Latgé , Eva Y. Andrei , N. Sandler

A density-functional approach on the hexagonal graphene lattice is developed using an exact numerical solution to the Hubbard model as the reference system. Both nearest-neighbour and up to third nearest-neighbour hoppings are considered…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 M. Ijäs , A. Harju

It is demonstrated that there is a characteristic impurity concentration, at which variation with concentration and overall appearance of the local density of states at the impurity site in graphene are changing their behavior. Features…

Disordered Systems and Neural Networks · Physics 2007-05-23 Yuriy V. Skrypnyk , Vadim M. Loktev