scholarly journals Углеродные наноструктуры на полупроводниковой подложке

2019 ◽  
Vol 61 (6) ◽  
pp. 1214
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Boron Nitride ◽  
Carbon Nanostructures ◽  
Graphene Nanoribbons ◽  
Strong Coupling Regime ◽  
Main Attention ◽  
Occupation Numbers ◽  
Analytical Expressions ◽  
Semiconducting Substrate ◽  
Lateral Heterostructure ◽  
Numerical Estimations

AbstractThe analytical expressions for the density of states and the occupation numbers are obtained for simple models of carbon nanostructures (graphene–boron nitride lateral heterostructure, decorated zigzag edges of semi-infinity graphene and graphene nanoribbons, and decorated carbyne). The main attention is placed to the strong-coupling regime of the nanostructures with a semiconducting substrate. The numerical estimations are given for the SiC substrate.

scholarly journals On the Energy Gaps Induced by a Semiconducting Substrate in the Graphene Density of States

2015 ◽  
Vol 9 (12) ◽  
pp. 234
Author(s):  
Sergey Yurevich Davydov ◽  
Alexander Alexandrovich Lebedev
Keyword(s):  
Electronic Spectrum ◽  
Density Of States ◽  
Energy Gap ◽  
Epitaxial Graphene ◽  
Energy Gaps ◽  
Densities Of States ◽  
Analytical Expressions ◽  
Semiconducting Substrate ◽  
Numerical Estimations

<p class="zhengwen"><span lang="EN-GB">The analytical expressions for the densities of states for graphene formed on semiconducting substrates are obtained. The problem on the induced gap is studied thoroughly. It is shown, that graphene electronic spectrum according to the relation between the system’s parameters can contain two gaps or one gap, overlapping with the energy gap of substrate. The gaps width dependences on the coupling regimes (tight and weak) are obtained. Numerical estimations are fulfilled for the epitaxial graphene on 6H-SiC{0001}.</span></p>

scholarly journals Цепочечная модель зигзагообразного контакта латеральных графеноподобных гетероструктур

2018 ◽  
Vol 44 (21) ◽  
pp. 55
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Boron Nitride ◽  
Density Of States ◽  
Structural Model ◽  
Hexagonal Boron Nitride ◽  
Two Dimensional ◽  
Occupation Numbers ◽  
Densities Of States ◽  
Spectrum Density ◽  
Analytical Expressions ◽  
Good Agreement

AbstractA simple structural model is proposed for the zigzag interface formed by contacting two-dimensional graphene-like compounds AB and CD (both free and formed on a metal). For the graphene–hexagonal boron nitride system, analytical expressions for the electron spectrum, density of states, and atom occupation numbers at the interface are obtained. The results of calculating the densities of states and occupation numbers within two alternative approximations are in good agreement.

scholarly journals Кластерная модель латеральной графеноподобной гетероструктуры: оценки перехода заряда

2018 ◽  
Vol 60 (9) ◽  
pp. 1815
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Charge Transfer ◽  
Boron Nitride ◽  
Cluster Model ◽  
Binary Compound ◽  
Metal Substrate ◽  
Two Dimensional ◽  
Occupation Numbers ◽  
Densities Of States ◽  
Local Densities ◽  
Analytical Expressions

AbstractA simple cluster model is proposed to describe zigzag and armchair contacts of graphene to a hexagonal two-dimensional binary compound adsorbed on a metal substrate. A graphene–boron nitride heterostructure (HS) is studied in detail. Analytical expressions are obtained for the local densities of states and the occupation numbers of contact atoms. The charge transfer for quasi-free HSs is analyzed. The energy of binding of a HS to a metal substrate is estimated.

scholarly journals APPLICATIONS OF DENSITY MATRICES IN A TRAPPED BOSE GAS

2006 ◽  
Vol 20 (15) ◽  
pp. 2189-2221 ◽  
Author(s):  
K. CH. CHATZISAVVAS ◽  
S. E. MASSEN ◽  
CH. C. MOUSTAKIDIS ◽  
C. P. PANOS
Keyword(s):  
Quantum Information ◽  
Bose Gas ◽  
Einstein Condensation ◽  
Density Distributions ◽  
Occupation Numbers ◽  
The One ◽  
Bose Einstein ◽  
Jensen Shannon Divergence ◽  
Analytical Expressions ◽  
Short Range Correlations

An overview of the Bose–Einstein condensation of correlated atoms in a trap is presented by examining the effect of interparticle correlations to one- and two-body properties of the above systems at zero temperature in the framework of the lowest order cluster expansion. Analytical expressions for the one- and two-body properties of the Bose gas are derived using Jastrow-type correlation function. In addition numerical calculations of the natural orbitals and natural occupation numbers are also carried out. Special effort is devoted for the calculation of various quantum information properties including Shannon entropy, Onicescu informational energy, Kullback–Leibler relative entropy and the recently proposed Jensen–Shannon divergence entropy. The above quantities are calculated for the trapped Bose gases by comparing the correlated and uncorrelated cases as a function of the strength of the short-range correlations. The Gross–Piatevskii equation is solved, giving the density distributions in position and momentum space, which are employed to calculate quantum information properties of the Bose gas.

Nonlinear optical response and transparency of hexagonal boron nitride hybrid graphene nanoribbons

2014 ◽  
Vol 614 ◽  
pp. 57-61 ◽  
Author(s):  
Hua Zhou ◽  
Zhong-Jun Zhou ◽  
Guang-Tao Yu ◽  
Wei Chen ◽  
Xu-Ri Huang ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Nonlinear Optical ◽  
Graphene Nanoribbons ◽  
Hexagonal Boron Nitride ◽  
Optical Response ◽  
Nonlinear Optical Response

scholarly journals О декорировании зигзагообразной кромки эпитаксиального графена

2019 ◽  
Vol 61 (1) ◽  
pp. 186
Author(s):  
С.Ю. Давыдов
Keyword(s):  
Electronic Structure ◽  
Graphene Sheet ◽  
Cluster Model ◽  
Dipole Interaction ◽  
Metal Substrate ◽  
Zigzag Edge ◽  
Occupation Numbers ◽  
Local Densities ◽  
Analytical Expressions

AbstractTwo approaches are proposed to the problem of the coupling of adsorbed particles with atoms of a zigzag edge of graphene formed on a metal substrate. The first approach is based on the Kalkstein and Soven scheme, which makes it possible to determine the electronic structure of a semi-infinite graphene sheet. The second approach is based on a cluster model of a zigzag edge. Analytical expressions are obtained for the local densities of the system’s states and the occupation numbers of a carbon adatom and an adparticle. The case of an isolated adparticle is considered in detail, and a method of taking into account the dipole–dipole interaction of particles aligned along the edge is proposed.

scholarly journals Exciton-phonon interaction in the strong-coupling regime in hexagonal boron nitride

2017 ◽  
Vol 95 (20) ◽  
Author(s):  
T. Q. P. Vuong ◽  
G. Cassabois ◽  
P. Valvin ◽  
S. Liu ◽  
J. H. Edgar ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Strong Coupling ◽  
Hexagonal Boron Nitride ◽  
Strong Coupling Regime ◽  
Phonon Interaction

Колебания слоя с расслоением в рамках градиентной теории упругости

2021 ◽  
pp. 3-15
Author(s):  
А.О. Ватульян ◽  
О.В. Явруян
Keyword(s):  
Boundary Integral Equations ◽  
Relative Length ◽  
Theory Of Elasticity ◽  
Boundary Integral ◽  
Stress Fields ◽  
Gradient Theory ◽  
Main Attention ◽  
Asymptotic Approach ◽  
Crack Tips ◽  
Analytical Expressions

The direct problem of antiplane oscillations of a layer with delamination in the context of the gradient theory of elasticity is considered. The gradient model proposed by Aifantis is taken as a mathematical model. The main attention has been paid to the analysis of mechanical fields at the crack bank and at its tips - stress concentrators. The study is carried out using the method of boundary integral equations (BIE). The BIE for the gradient of displacement field on the crack is constructed. The analysis of the constructed BIE is carried out and the cubic singularity is explicitly revealed. The solution of singular BIE is constructed using approximating Chebyshev polynomials. A study for cracks of small relative length - asymptotic approach is carried out, simple semi-analytical expressions for constructing the crack swap function are obtained, the range of efficiency of the asymptotic approach is obtained. The stress fields in the area of the crack tips are constructed. Numerical results of computational experiments are presented.

scholarly journals Graphene nanoribbons on hexagonal boron nitride: Deposition and transport characterization

2019 ◽  
Vol 114 (17) ◽  
pp. 173101 ◽  
Author(s):  
Tobias Preis ◽  
Christian Kick ◽  
Andreas Lex ◽  
Dieter Weiss ◽  
Jonathan Eroms ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Graphene Nanoribbons ◽  
Hexagonal Boron Nitride

scholarly journals A Review of Geometry, Construction and Modelling for Carbon Nanotori

2019 ◽  
Vol 9 (11) ◽  
pp. 2301 ◽  
Author(s):  
Pakhapoom Sarapat ◽  
James Hill ◽  
Duangkamon Baowan
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanostructures ◽  
Single Walled Carbon Nanotubes ◽  
Continuum Approximation ◽  
Interaction Energies ◽  
Jones Potential ◽  
Lennard Jones ◽  
Walled Carbon Nanotubes ◽  
Analytical Expressions ◽  
The Continuum

After the discovery of circular formations of single walled carbon nanotubes called fullerene crop circles, their structure has become one of the most researched amongst carbon nanostructures due to their particular interesting physical properties. Several experiments and simulations have been conducted to understand these intriguing objects, including their formation and their hidden characteristics. It is scientifically conceivable that these crop circles, nowadays referred to as carbon nanotori, can be formed by experimentally bending carbon nanotubes into ring shaped structures or by connecting several sections of carbon nanotubes. Toroidal carbon nanotubes are likely to have many applications, especially in electricity and magnetism. In this review, geometry, construction, modelling and possible applications are discussed and the existing known analytical expressions, as obtained from the Lennard-Jones potential and the continuum approximation, for their interaction energies with other nanostructures are summarised.

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