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We examine the conditions necessary for the presence of localized magnetic moments on adatoms with inner shell electrons in graphene. We show that the low density of states at the Dirac point, and the anomalous broadening of the adatom…

Strongly Correlated Electrons · Physics 2008-07-13 Bruno Uchoa , Valeri N. Kotov , N. M. R. Peres , A. H. Castro Neto

We compare the conductance of an undoped graphene sheet with a small region subject to an electrostatic gate potential for the cases that the dynamics in the gated region is regular (disc-shaped region) and classically chaotic (stadium).…

Mesoscale and Nanoscale Physics · Physics 2009-06-10 J. H. Bardarson , M. Titov , P. W. Brouwer

We study topological bound states in quantum dots defined by an electric field in bilayer graphene. An external field is perpendicular to the bilayer and changes sign in a finite region that defines the quantum dot. The electric field opens…

Mesoscale and Nanoscale Physics · Physics 2026-03-16 Wlodzimierz Jaskolski

We investigate the electrostatic confinement of charge carriers in a gapped graphene quantum dot in the presence of a magnetic flux. The circular quantum dot is defined by an electrostatic gate potential delimited in an infinite graphene…

Mesoscale and Nanoscale Physics · Physics 2021-06-02 Ahmed Bouhlal , Abdelhadi Belouad , Ahmed Jellal , Hocine Bahlouli

Based on the tight-binding model calculations and photonic experimental visualization on graphene, we report the domain-wall-induced gapped topological kink states and topological corner states. In graphene, domain walls with gapless…

Mesoscale and Nanoscale Physics · Physics 2020-05-26 Yuting Yang , Ziyuan Jia , Yijia Wu , Zhi-Hong Hang , Hua Jiang , X. C. Xie

We propose a new method to use gapped graphene as barrier to confine electrons in gapless graphene and form a good quantum dot, which can be realized on an oxygen-terminated $SiO_{2}$ substrate partly H-passivated. In particular, we use…

Mesoscale and Nanoscale Physics · Physics 2009-10-27 Qiong Ma , Zhi-Rong Lin , Tao Tu , Guang-Can Guo , Guo-Ping Guo

We demonstrate theoretically that quantum dots in bilayers of graphene can be realized. A position-dependent doping breaks the equivalence between the upper and lower layer and lifts the degeneracy of the positive and negative momentum…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 J. Milton Pereira , P. Vasilopoulos , F. M. Peeters

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

We show that when the pseudomagnetic fields created by long wavelength deformations are appropriately coupled with a scalar electric potential, a significant energy gap can emerge due to the formation of a Haldane state. Ramifications of…

Mesoscale and Nanoscale Physics · Physics 2011-05-31 T. Low , F. Guinea , M. I. Katsnelson

We have carried out first-principles calculations on electronic properties of graphene quantum dots embedded in hexagonal boron nitride monolayer sheets. The calculations with density functional theory show that the band gaps of quantum…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 Junwen Li , Vivek B. Shenoy

Coupled electron-hole states are realized in a system consisting of a combination of an electrostatic potential barrier and ring-shaped potential well, which resembles a circular dipole. A perpendicular magnetic field induces confined…

Mesoscale and Nanoscale Physics · Physics 2019-04-05 R. Van Pottelberge , F. M. Peeters

We theoretically analyze the possibility to confine electrons in single-layer graphene with the help of metallic gates, via the evaluation of the density of states of such a gate-defined quantum dot in the presence of a ring-shaped metallic…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 Martin Schneider , Piet W. Brouwer

Graphene-based superlattice (SL) formed by a periodic gap modulation is studied theoretically using a Dirac-type Hamiltonian. Analyzing the dispersion relation we have found that new Dirac points arise in the electronic spectrum under…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 G. M. Maksimova , E. S. Azarova , A. V. Telezhnikov , V. A. Burdov

Quantum dots based on the graphene stripes show unconventional optical properties in the THz frequency range. The graphene quantum dot (GQD) is made of electrically gated stripe with zigzag edges. Inside the active region (AR), which is…

Mesoscale and Nanoscale Physics · Physics 2019-09-04 S. E. Shafraniuk

Tuning interactions between Dirac states in graphene has attracted enormous interest because it can modify the electronic spectrum of the two-dimensional material, enhance electron correlations, and give rise to novel condensed-matter…

Graphene is a unique two-dimensional material with rich new physics and great promise for applications in electronic devices. Physical phenomena such as the half-integer quantum Hall effect and high carrier mobility are critically dependent…

Considerable efforts have been made to trap massless Dirac fermions in graphene monolayer, but only quasi-bound states are realized in continuous graphene sheets up to now. Here, we demonstrate the realization of bound states in nanoscale…

Mesoscale and Nanoscale Physics · Physics 2017-04-05 Jia-Bin Qiao , Hua Jiang , Haiwen Liu , Hong Yang , Ning Yang , Kai-Yao Qiao , Lin He

We present a simple technique to fabricate graphene quantum dots in a cryostat. It relies upon the controlled rupture of a suspended graphene sheet subjected to the application of a large electron current. This results in the in-situ…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Joel Moser , Adrian Bachtold

The magnetic field dependence of energy levels in gapped single- and bilayer graphene quantum dots (QDs) defined by electrostatic gates is studied analytically in terms of the Dirac equation. Due to the absence of sharp edges in these types…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Patrik Recher , Johan Nilsson , Guido Burkard , Bjoern Trauzettel

Stimulated by recent advances in isolating graphene, we discovered that quantum dot can be trapped in Z-shaped graphene nanoribbon junciton. The topological structure of the junction can confine electronic states completely. By varying…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Z. F. Wang , Huaixiu Zheng , Q. W. Shi , Jie Chen , Qunxiang Li , J. G. Hou