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We study the energy levels of carriers confined in a magnetic quantum dot of graphene surrounded by a infinite graphene sheet in the presence of energy gap. The eigenspinors are derived for the valleys $K$ and $K'$, while the associated…

Mesoscale and Nanoscale Physics · Physics 2020-08-07 Abderrahim Farsi , Abdelhadi Belouad , Ahmed Jellal

In this paper, we predict the existence of low-frequency nonlocal plasmon excitations at the vacuum-surface interface of a superlattice of $N$ graphene layers interacting with a thick conducting substrate. This is different from graphite…

Mesoscale and Nanoscale Physics · Physics 2015-08-11 Godfrey Gumbs , Andrii Iurov , Jhao-Ying Wu , M. F. Lin , Paula Fekete

The electron and current density distributions in the close proximity of quantum point contacts (QPCs) are investigated. A three dimensional Poisson equation is solved self-consistently to obtain the electron density and potential profile…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 S. Arslan , E. Cicek , D. Eksi , S. Aktas , A. Weichselbaum , A. Siddiki

We study the propagation of electrons in a circular quantum dot of gapped graphene subject to the magnetic flux $\phi$. We present analytical expressions for the eigenstates, scattering coefficients, scattering efficiency and radial…

Mesoscale and Nanoscale Physics · Physics 2020-06-16 Bouchaib Lemaalem , Abdelhadi Belouad , Miloud Mekkaoui , Ahmed Jellal

We analyze the bound-state spectra of mass-profile quantum dots in graphene, a system at current experimental reach. Homogeneous perpendicular magnetic fields are also considered which result in breaking the valley degeneracy. The spectra…

Mesoscale and Nanoscale Physics · Physics 2015-04-24 A. Gutiérrez-Rubio , T. Stauber

The interaction of fast charged particles with graphene layers can generate electromagnetic modes. This wake effect has been recently proposed for short-wavelength, high-gradient particle acceleration and for obtaining brilliant radiation…

A model for quantum dots is proposed, in which the motion of a few electrons in a three-dimensional harmonic oscillator potential under the influence of a homogeneous magnetic field of arbitrary direction is studied. The spectrum and the…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 W. D. Heiss , R. G. Nazmitdinov

Quantum dots induced by a strong magnetic field applied to a single layer of graphene in the perpendicular direction are investigated. The dot is defined by a model potential which consists of a well of depth $\Delta V$ relative to a flat…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 P. A. Maksym , M. Roy , M. F. Craciun , M. Yamamoto , S. Tarucha , H. Aoki

Graphene is considered to be a promising material for future electronics. The envisaged transistor applications often rely on precision cutting of graphene sheets with nanometer accuracy. In this letter we demonstrate graphene-based quantum…

Mesoscale and Nanoscale Physics · Physics 2010-07-27 S. Neubeck , L. A. Ponomarenko , F. Freitag , A. J. M. Giesbers , U. Zeitler , S. V. Morozov , P. Blake , A. K. Geim , K. S. Novoselov

The electromagnetic response of graphene, expressed by the dielectric function, and the spectrum of collective excitations are studied as a function of wave vector and frequency. Our calculation is based on the full band structure,…

Strongly Correlated Electrons · Physics 2009-09-03 A. Hill , S. A. Mikhailov , K. Ziegler

The dynamical dielectric function of two dimensional graphene at arbitrary wave vector $q$ and frequency $\omega$, $\epsilon(q,\omega)$, is calculated in the self-consistent field approximation. The results are used to find the dispersion…

Strongly Correlated Electrons · Physics 2008-05-19 E. H. Hwang , S. Das Sarma

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

The orbital and spin magnetization of a cavity-embedded quantum dot array defined in a GaAs heterostructure are calculated within quantum-electrodynamical density-functional theory (QEDFT). To this end a gradient-based exchange-correlation…

Mesoscale and Nanoscale Physics · Physics 2022-09-29 Vidar Gudmundsson , Vram Mughnetsyan , Nzar Rauf Abdullah , Chi-Shung Tang , Valeriu Moldoveanu , Andrei Manolescu

We discuss spin-$\frac12$ two-dimensional (2D) Heisenberg antiferromagnet (AF) on a square lattice at T=0 in strong magnetic field H near its saturation value $H_c$. A perturbation approach is proposed to obtain spectrum of magnons with…

Strongly Correlated Electrons · Physics 2009-02-12 A. V. Syromyatnikov

We have developed an analytical formulation to calculate the plasmon dispersion relation for a two-dimensional layer which is encapsulated within a narrow spatial gap between two bulk half-space plasmas. This is based on a solution of the…

Mesoscale and Nanoscale Physics · Physics 2016-05-25 Godfrey Gumbs , Norman J. M. Horing , Andrii Iurov , Dipendra Dahal

We apply quantum electrodynamical density functional theory to obtain the electronic density, the spin polarization, as well as the orbital and the spin magnetization of square periodic arrays of quantum dots or antidots subjected to the…

Mesoscale and Nanoscale Physics · Physics 2023-06-13 Vram Mughnetsyan , Vidar Gudmundsson , Nzar Rauf Abdullah , Chi-Shung Tang , Valeriu Moldoveanu , Andrei Manolescu

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

Laterally localized electronic states are identified on a single layer of graphene on ruthenium. The individual states are separated by 3 nm and comprise regions of about 90 carbon atoms. This constitutes a quantum dot array, evidenced by…

Materials Science · Physics 2010-07-08 H. G. Zhang , H. Hu , Y. Pan , J. H. Mao , M. Gao , H. M. Guo , S. X. Du , T. Greber , H. -J. Gao

Motivated by the recent experiment of Hochgraefe et al., we have investigated the magnetoplasmon excitations in a periodic array of quantum wires with a periodic modulation along the wire direction. The equilibrium and dynamic properties of…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 B. P. van Zyl , E. Zaremba

In this paper we study the excitation spectrum of single- and multi-layer graphene beyond the Dirac cone approximation. The dynamical polarizability of graphene is computed using a full $\pi$-band tight-binding model, considering the…

Mesoscale and Nanoscale Physics · Physics 2011-07-29 Shengjun Yuan , Rafael Roldán , Mikhail I. Katsnelson