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We outline a Kohn-Sham-Dirac density-functional-theory (DFT) scheme for graphene sheets that treats slowly-varying inhomogeneous external potentials and electron-electron interactions on an equal footing. The theory is able to account for…

Strongly Correlated Electrons · Physics 2008-09-23 Marco Polini , Andrea Tomadin , Reza Asgari , A. H. MacDonald

We explore the gapped graphene structure in the two-dimensional plane in the presence of the Rosen-Morse potential and an external uniform magnetic field. In order to describe the corresponding structure, we consider the propagation of…

Mesoscale and Nanoscale Physics · Physics 2024-09-04 A. Kalani , Alireza Amani , M. A. Ramzanpour

Graphene quantum dots are considered as promising alternatives to quantum dots in III-V semiconductors, e.g., for the use as spin qubits due to their consistency made of light atoms including spin-free nuclei which both imply relatively…

Mesoscale and Nanoscale Physics · Physics 2016-04-20 Markus Morgenstern , Nils Freitag , Aviral Vaid , Marco Pratzer , Marcus Liebmann

Klein quantum dot (KQD) refers to a QD with quasi-bound states and a finite trapping time, which has been observed in experiments focused on graphene recently. In this paper, we develop a numerical method to calculate local density of…

Mesoscale and Nanoscale Physics · Physics 2018-05-10 Jiaojiao Zhou , Shu-guang Cheng , Hua Jiang

We study the electronic states of graphene in piecewise constant potentials using the continuum Dirac equation appropriate at low energies, and a transfer matrix method. For superlattice potentials, we identify patterns of induced Dirac…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 D. P. Arovas , L. Brey , H. A. Fertig , Eun-Ah Kim , K. Ziegler

Artificial molecular states of double quantum dots defined in bilayer graphene are studied with the atomistic tight-binding and its low-energy continuum approximation. We indicate that the extended electron wave functions have opposite…

Mesoscale and Nanoscale Physics · Physics 2017-08-02 D. P. Żebrowski , F. M. Peeters , B. Szafran

We analyse the electronic and optical properties of graphene quantum dots (GQD) using accurate \textit{ab initio} many-body $GW$ and Bethe-Salpeter calculations. We show that most pristine GQD, including structures with irregular shapes,…

Mesoscale and Nanoscale Physics · Physics 2020-03-26 Denis M. Basko , Ivan Duchemin , Xavier Blase

In 2015 experiments were performed with superconducting microwave photonic crystals emulating artificial graphene B. Dietz, T. Klaus, M. Miski-Oglu, and A. Richter, Phys. Rev. B 91, 035411 (2015)]. The associated density of states comprises…

Mesoscale and Nanoscale Physics · Physics 2021-05-11 Wulayimu Maimaiti , Barbara Dietz , Alexei Andreanov

The conductivity of graphene on a boron nitride substrate exhibits features in the terahertz (THz) and infrared (IR) frequency regimes that are associated with the periodic moir\'e pattern formed by the weakly coupled two-dimensional…

Mesoscale and Nanoscale Physics · Physics 2015-10-14 Ashley M. DaSilva , Jeil Jung , Shaffique Adam , Allan H. MacDonald

We study the effects of insulating oxides in their crystalline forms on the energy band structure of monolayer and bilayer graphene using a \textit{first principles} density functional theory based electronic structure method and a local…

Materials Science · Physics 2011-12-09 Priyamvada Jadaun , Sanjay K. Banerjee , Leonard F. Register , Bhagawan Sahu

Motivated by quantum chemistry calculations, showing that molecular adsorption in graphene takes place on preferential sites of the honeycomb lattice, we study the effect of an isolated impurity on the local electronic properties of a…

Mesoscale and Nanoscale Physics · Physics 2009-09-30 F. M. D. Pellegrino , G. G. N. Angilella , R. Pucci

We study electron scattering in graphene quantum dots (GQDs) under the combined influence of a magnetic field, an energy gap, and circularly polarized laser irradiation. Using the Floquet approach and the Dirac equation, we derive the…

Mesoscale and Nanoscale Physics · Physics 2025-01-30 Ahmed Bouhlal , Mohammed El Azar , Aotmane En Naciri , Elmustapha Feddi , Ahmed Jellal

We theoretically analyse the possibility to electrostatically confine electrons in circular quantum dot arrays, impressed on contacted graphene nanoribbons by top gates. Utilising exact numerical techniques, we compute the scattering…

Mesoscale and Nanoscale Physics · Physics 2016-04-21 Holger Fehske , Georg Hager , Andreas Pieper

A number of interesting properties of graphene and graphite are postulated to derive from the peculiar bandstructure of graphene. This bandstructure consists of conical electron and hole pockets that meet at a single point in momentum (k)…

Strongly Correlated Electrons · Physics 2007-05-23 Aaron Bostwick , Taisuke Ohta , Thomas Seyller , K. Horn , Eli Rotenberg

The electrostatic confinement of massless charge carriers is hampered by Klein tunneling. Circumventing this problem in graphene mainly relies on carving out nanostructures or applying electric displacement fields to open a band gap in…

Research on graphene has revealed remarkable phenomena arising in the honeycomb lattice. However, the quantum spin Hall effect predicted at the K point could not be observed in graphene and other honeycomb structures of light elements due…

Mesoscale and Nanoscale Physics · Physics 2015-03-23 W. Beugeling , E. Kalesaki , C. Delerue , Y. -M. Niquet , D. Vanmaekelbergh , C. Morais Smith

An analysis of the electron localization properties in doped graphene is performed by doing a numerical multifractal analysis. By obtaining the singularity spectrum of a tight-binding model, it is found that the electron wave functions…

Disordered Systems and Neural Networks · Physics 2013-07-01 J. E. Barrios-Vargas , Gerardo G. Naumis

We calculate the low-frequency magnetoplasmon excitation spectrum for a square array of quantum dots on a two-dimensional (2D) graphene layer. The confining potential is linear in the distance from the center of the quantum dot. The…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Oleg L. Berman , Godfrey Gumbs , P. M. Echenique

Polaron spectral functions are computed for highly doped graphene-on-substrate and other atomically thin graphitic systems using the diagrammatic Monte Carlo technique. The specific aim is to investigate the effects of interaction on…

Strongly Correlated Electrons · Physics 2012-11-30 J. P. Hague

We discuss theoretically the local density of states (LDOS) of a graphene sheet hosting two distant adatoms located at the center of the hexagonal cells. By putting laterally a Scanning Tunneling Microscope (STM) tip over a carbon atom, two…

Strongly Correlated Electrons · Physics 2014-11-25 A. C. Seridonio , K. Kristinsson , M. de Souza , F. M. Souza , L. H. Guessi , R. S. Machado , I. A. Shelykh