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Graphene quantum dots (GQD's) have optical properties which are very different from those of an extended graphene sheet. In this Article we explore how the size, shape and edge--structure of a GQD affect its optical conductivity. Using…

Materials Science · Physics 2018-03-14 Rico Pohle , Eleftheria G. Kavousanaki , Keshav M. Dani , Nic Shannon

We present an accurate interatomic potential for graphene, constructed using the Gaussian Approximation Potential (GAP) machine learning methodology. This GAP model obtains a faithful representation of a density functional theory (DFT)…

Materials Science · Physics 2018-02-14 Patrick Rowe , Gábor Csányi , Dario Alfè , Angelos Michaelides

We consider a square lattice configuration of circular gate-defined quantum dots in an unbiased graphene sheet and calculate the electronic, particularly spectral properties of finite albeit actual sample sized systems by means of a…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 A. Pieper , R. L. Heinisch , G. Wellein , H. Fehske

Spin-polarized first-principles calculations have been performed to tune the electronic and optical properties of graphene (G) and boron-nitride (BN) quantum dots (QDs) through molecular charge-transfer using Tetracyanoquinodimethane (TCNQ)…

Materials Science · Physics 2017-09-13 Arkamita Bandyopadhyay , Sharma SRKC Yamijala , Swapan K Pati

The distribution of net electric charge in graphene is investigated, using both a constitutive atomic charge-dipole interaction model and an approximate analytical solution to Laplace's equation. We demonstrate a strong size dependence of…

Mesoscale and Nanoscale Physics · Physics 2009-09-21 Zhao Wang , Robert W. Scharstein

Quantum dots (QDs) are applied in a variety of fields ranging from photovoltaics to biomedical imaging. Even the smallest QDs present a complicated potential energy surface characterized by a large set of stationary points. Each local…

Materials Science · Physics 2016-08-18 Vitaly V. Chaban

Employing a combination of many-body configuration interaction method described by extended Hubbard model along with first principle calculations we predict the emergence of high oscillator strength at near-IR region which originates from…

Materials Science · Physics 2016-11-15 Madhuri Mukhopadhyay , Bradraj Pandey , Swapan K Pati

We report on a detailed investigation of the shell-filling sequence in electrostatically defined elliptic bilayer graphene quantum dots (QDs) in the regime of low charge carrier occupation, $N \leq 12$, by means of magnetotransport…

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 the field of condensed matter, graphene plays a central role as an emerging material for nanoelectronics. Nevertheless, graphene is a semimetal, which constitutes a severe limitation for some future applications. Therefore, a lot of…

Mesoscale and Nanoscale Physics · Physics 2018-10-24 S. Zhao , J. Lavie , L. Rondin , L. Orcin-Chaix , C. Diederichs , Ph. Roussignol , Y. Chassagneux , C. Voisin , K. Müllen , A. Narita , S. Campidelli , J. S. Lauret

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

We experimentally investigate electrical transport properties of graphene, which is a two dimensional (2D) conductor with relativistic energy dispersion relation. By investigating single- and bi-layer graphene devices with different aspect…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 F. Miao , S. Wijeratne , U. Coskun , Y. Zhang , C. N. Lau

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

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

We explore the spatial variations of the unoccupied electronic states of graphene epitaxially grown on Ru(0001) and observed three unexpected features: the first graphene image state is split in energy, unlike all other image states, the…

Quantum dot - graphene hybrid materials have raised significant interest due to the unique synergy of the optical properties of colloidal quantum dots (QDs) and the transport properties of graphene. This stimulated the development of…

Mesoscale and Nanoscale Physics · Physics 2026-01-21 Beatriz Martín-García , Anatolii Polovitsyn , Mirko Prato , Iwan Moreels

The structure stability and electronic properties of edge carboxylated hexagonal and triangular graphene quantum dots are investigated by using density functional theory. The calculated binding energies show that the hexagonal clusters with…

Mesoscale and Nanoscale Physics · Physics 2018-03-14 Hazem Abdelsalam , Hanan Elhaes , Medhat A. Ibrahim

On the basis of first-principles calculations and the special displacement method, we demonstrate the quantum confinement scaling law of the phonon-induced gap renormalization of graphene quantum dots (GQDs). We employ zigzag-edged GQDs…

Materials Science · Physics 2021-10-19 Marios Zacharias , Pantelis C. Kelires

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

We theoretically analyze the scattering process of an electron on a graphene quantum dot (GQD) exposed to an external light irradiation. We prove that for suitable choices of the light polarization state, there emerge scattering resonances,…

Mesoscale and Nanoscale Physics · Physics 2023-09-13 Adrian Pena