Records |
Author |
Mirzakhani, M.; Zarenia, M.; Ketabi, S.A.; da Costa, D.R.; Peeters, F.M. |
Title |
Energy levels of hybrid monolayer-bilayer graphene quantum dots |
Type ![sorted by Type field, ascending order (up)](img/sort_asc.gif) |
A1 Journal article |
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
93 |
Issue |
93 |
Pages |
165410 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Often real samples of graphene consist of islands of both monolayer and bilayer graphene. Bound states in such hybrid quantum dots are investigated for (i) a circular single-layer graphene quantum dot surrounded by an infinite bilayer graphene sheet and (ii) a circular bilayer graphene quantum dot surrounded by an infinite single-layer graphene. Using the continuum model and applying zigzag boundary conditions at the single-layer-bilayer graphene interface, we obtain analytical results for the energy levels and the corresponding wave spinors. Their dependence on perpendicular magnetic and electric fields are studied for both types of quantum dots. The energy levels exhibit characteristics of interface states, and we find anticrossings and closing of the energy gap in the presence of a bias potential. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000373572700004 |
Publication Date |
2016-04-09 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9950;2469-9969; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
26 |
Open Access |
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Notes |
; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO)-CNPq project between Flanders and Brazil and the Brazilian Science Without Borders program. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:133261 |
Serial |
4174 |
Permanent link to this record |
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Author |
Mirzakhani, M.; Zarenia, M.; da Costa, D.R.; Ketabi, S.A.; Peeters, F.M. |
Title |
Energy levels of ABC-stacked trilayer graphene quantum dots with infinite-mass boundary conditions |
Type ![sorted by Type field, ascending order (up)](img/sort_asc.gif) |
A1 Journal article |
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
94 |
Issue |
94 |
Pages |
165423 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using the continuum model, we investigate the confined states and the corresponding wave functions of ABC-stacked trilayer graphene (TLG) quantum dots (QDs). First, a general infinite-mass boundary condition is derived and applied to calculate the electron and hole energy levels of a circular QD in both the absence and presence of a perpendicular magnetic field. Our analytical results for the energy spectra agree with those obtained by using the tight-binding model, where a TLG QD is surrounded by a staggered potential. Our findings show that (i) the energy spectrum exhibits intervalley symmetry E-K(e)(m) = -E-K'(h)(m) for the electron (e) and hole (h) states, where m is the angular momentum quantum number, (ii) the zero-energy Landau level (LL) is formed by the magnetic states with m <= 0 for both Dirac valleys, that is different from monolayer and bilayer graphene QD with infinite-mass potential in which only one of the cones contributes, and (iii) groups of three quantum Hall edge states in the tight-binding magnetic spectrum approach the zero LL, which results from the layer symmetry in TLG QDs. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000386168000011 |
Publication Date |
2016-10-19 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9950;2469-9969; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Brazilian Council for Research (CNPq), the Science without Borders program, PRONEX/FUNCAP, and CAPES foundation. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:138174 |
Serial |
4353 |
Permanent link to this record |
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Author |
Mirzakhani, M.; Zarenia, M.; Vasilopoulos, P.; Ketabi, S.A.; Peeters, F.M. |
Title |
Landau levels in biased graphene structures with monolayer-bilayer interfaces |
Type ![sorted by Type field, ascending order (up)](img/sort_asc.gif) |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
96 |
Issue |
12 |
Pages |
125430 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The electron energy spectrum in monolayer-bilayer-monolayer and in bilayer-monolayer-bilayer graphene structures is investigated and the effects of a perpendicular magnetic field and electric bias are studied. Different types of monolayer-bilayer interfaces are considered as zigzag (ZZ) or armchair (AC) junctions which modify considerably the bulk Landau levels (LLs) when the spectra are plotted as a function of the center coordinate of the cyclotron orbit. Far away from the two interfaces, one obtains the well-known LLs for extended monolayer or bilayer graphene. The LL structure changes significantly at the two interfaces or junctions where the valley degeneracy is lifted for both types of junctions, especially when the distance between them is approximately equal to the magnetic length. Varying the nonuniform bias and the width of this junction-to-junction region in either structure strongly influence the resulting spectra. Significant differences exist between ZZ and AC junctions in both structures. The densities of states (DOSs) for unbiased structures are symmetric in energy whereas those for biased structures are asymmetric. An external bias creates interface LLs in the gaps between the LLs of the unbiased system in which the DOS can be quite small. Such a pattern of LLs can be probed by scanning tunneling microscopy. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000411321800003 |
Publication Date |
2017-09-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
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Notes |
; This work was supported by the BOF-UA (Bijzonder Onderzoeks Fonds), the Canadian NSERC through Grant No. OGP0121756 (P.V.), and the Methusalem Program of the Flemish Government. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:146746 |
Serial |
4787 |
Permanent link to this record |
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Author |
Nakhaee, M.; Ketabi, S.A.; Peeters, F.M. |
Title |
Tight-binding model for borophene and borophane |
Type ![sorted by Type field, ascending order (up)](img/sort_asc.gif) |
A1 Journal article |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
97 |
Issue |
12 |
Pages |
125424 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Starting from the simplified linear combination of atomic orbitals method in combination with first-principles calculations, we construct a tight-binding (TB) model in the two-centre approximation for borophene and hydrogenated borophene (borophane). The Slater and Koster approach is applied to calculate the TB Hamiltonian of these systems. We obtain expressions for the Hamiltonian and overlap matrix elements between different orbitals for the different atoms and present the SK coefficients in a nonorthogonal basis set. An anisotropic Dirac cone is found in the band structure of borophane. We derive a Dirac low-energy Hamiltonian and compare the Fermi velocities with that of graphene. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000427983700004 |
Publication Date |
2018-03-21 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
45 |
Open Access |
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Notes |
; Discussions with Dr. Vahid Derakhshan and M. A. M. Keshtan are gratefully acknowledged. This paper is supported by the Methusalem program of the Flemish government and the FLAT-ERA Project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:150836UA @ admin @ c:irua:150836 |
Serial |
4987 |
Permanent link to this record |
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Author |
Nakhaee, M.; Ketabi, S.A.; Peeters, F.M. |
Title |
Dirac nodal line in bilayer borophene : tight-binding model and low-energy effective Hamiltonian |
Type ![sorted by Type field, ascending order (up)](img/sort_asc.gif) |
A1 Journal article |
Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
98 |
Issue |
11 |
Pages |
115413 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Bilayer hexagonal borophene, which is bound together through pillars, is a novel topological semimetal. Using density functional theory, we investigate its electronic band structure and show that it is a Dirac material which exhibits a nodal line. A tight-binding model was constructed based on the Slater-Koster approach, which accurately models the electronic spectrum. We constructed an effective four-band model Hamiltonian to describe the spectrum near the nodal line. This Hamiltonian can be used as a new platform to study the new properties of nodal line semimetals. We found that the nodal line is created by edge states and is very robust against perturbations and impurities. Breaking symmetries can split the nodal line, but cannot open a gap. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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Language |
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Wos |
000443916200007 |
Publication Date |
2018-09-06 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
19 |
Open Access |
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Notes |
; This work was supported by the Methusalem program of the Flemish government and the graphene FLAG-ERA project TRANS-2D-TMD. ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:153649UA @ admin @ c:irua:153649 |
Serial |
5090 |
Permanent link to this record |
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Author |
Nakhaee, M.; Yagmurcukardes, M.; Ketabi, S.A.; Peeters, F.M. |
Title |
Single-layer structures of a100- and b010-Gallenene : a tight-binding approach |
Type ![sorted by Type field, ascending order (up)](img/sort_asc.gif) |
A1 Journal article |
Year |
2019 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
Volume |
21 |
Issue |
28 |
Pages |
15798-15804 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using the simplified linear combination of atomic orbitals (LCAO) method in combination with ab initio calculations, we construct a tight-binding (TB) model for two different crystal structures of monolayer gallium: a(100)- and b(010)-Gallenene. The analytical expression for the Hamiltonian and numerical results for the overlap matrix elements between different orbitals of the Ga atoms and for the Slater and Koster (SK) integrals are obtained. We find that the compaction of different structures affects significantly the formation of the orbitals. The results for a(100)-Gallenene can be very well explained with an orthogonal basis set, while for b(010)-Gallenene we have to assume a non-orthogonal basis set in order to construct the TB model. Moreover, the transmission properties of nanoribbons of both monolayers oriented along the AC and ZZ directions are also investigated and it is shown that both AC- and ZZ-b(010)-Gallenene nanoribbons exhibit semiconducting behavior with zero transmission while those of a(100)-Gallenene nanoribbons are metallic. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000476603700057 |
Publication Date |
2019-06-27 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1463-9076; 1463-9084 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.123 |
Times cited |
14 |
Open Access |
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Notes |
; This work is supported by the Methusalem program of the Flemish government and the FLAG-ERA project TRANS-2D-TMD. This work is supported by the Flemish Science Foundation (FWO-Vl) by a post-doctoral fellowship (M. Y.). M. N. is partially supported by BFO (Uantwerpen). ; |
Approved |
Most recent IF: 4.123 |
Call Number |
UA @ admin @ c:irua:161881 |
Serial |
5427 |
Permanent link to this record |
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Author |
Nakhaee, M.; Ketabi, S.A.; Peeters, F.M. |
Title |
Tight-binding studio : a technical software package to find the parameters of tight-binding Hamiltonian |
Type ![sorted by Type field, ascending order (up)](img/sort_asc.gif) |
A1 Journal article |
Year |
2020 |
Publication |
Computer Physics Communications |
Abbreviated Journal |
Comput Phys Commun |
Volume |
254 |
Issue |
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Pages |
107379-10 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We present the Tight-Binding Studio (TB Studio) software package that calculates the different parameters of a tight-binding Hamiltonian from a set of Bloch energy bands obtained from first principle theories such as density functional theory, Hartree-Fock calculations or semi-empirical band-structure theory. This will be helpful for scientists who are interested in studying electronic and optical properties of structures using Green's function theory within the tight-binding approximation. TB Studio is a cross-platform application written in C++ with a graphical user interface design that is user-friendly and easy to work with. This software is powered by Linear Algebra Package C interface library for solving the eigenvalue problems and the standard high performance OpenGL graphic library for real time plotting. TB Studio and its examples together with the tutorials are available for download from tight-binding.com. Program summary Program Title: Tight-Binding Studio Program Files doi:http://dx.doi.org/10.17632/j6x5mwzm2d.1 Licensing provisions: LGPL Programming language: C++ External routines: BLAS, LAPACK, LAPACKE, wxWidgets, OpenGL, MathGL Nature of problem: Obtaining Tight-Binding Hamiltonian from a set of Bloch energy bands obtained from first-principles calculations. Solution method: Starting from the simplified LCAO method, a tight-binding model in the two-center approximation is constructed. The Slater and Koster (SK) approach is used to calculate the parameters of the TB Hamiltonian. By using non-linear fitting approaches the optimal values of the SK parameters are obtained such that the TB energy eigenvalues are as close as possible to those from first-principles calculations. We obtain the expression for the Hamiltonian and the overlap matrix elements between the different orbitals of the different atoms in an orthogonal or non-orthogonal basis set. (C) 2020 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000541251200030 |
Publication Date |
2020-05-18 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0010-4655 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.3 |
Times cited |
27 |
Open Access |
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Notes |
; This work was supported by the Methusalem program of the Flemish government, Belgium and M. Nakhaee was supported by a BOF-fellowship (UAntwerpen), Belgium. ; |
Approved |
Most recent IF: 6.3; 2020 IF: 3.936 |
Call Number |
UA @ admin @ c:irua:170149 |
Serial |
6630 |
Permanent link to this record |
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Author |
Nakhaee, M.; Ketabi, S.A.; Peeters, F.M. |
Title |
Machine learning approach to constructing tight binding models for solids with application to BiTeCl |
Type ![sorted by Type field, ascending order (up)](img/sort_asc.gif) |
A1 Journal article |
Year |
2020 |
Publication |
Journal Of Applied Physics |
Abbreviated Journal |
J Appl Phys |
Volume |
128 |
Issue |
21 |
Pages |
215107 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Finding a tight-binding (TB) model for a desired solid is always a challenge that is of great interest when, e.g., studying transport properties. A method is proposed to construct TB models for solids using machine learning (ML) techniques. The approach is based on the LCAO method in combination with Slater-Koster (SK) integrals, which are used to obtain optimal SK parameters. The lattice constant is used to generate training examples to construct a linear ML model. We successfully used this method to find a TB model for BiTeCl, where spin-orbit coupling plays an essential role in its topological behavior. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000597311900001 |
Publication Date |
2020-12-03 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.2 |
Times cited |
10 |
Open Access |
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Notes |
; This work was supported by the Methusalem program of the Flemish government and was partially supported by BOF (UAntwerpen Grant Reference No. ADPERS/BAP/RS/ 2019). We would like to thank one of the anonymous referees for assisting us in making the paper more accessible to the reader. ; |
Approved |
Most recent IF: 3.2; 2020 IF: 2.068 |
Call Number |
UA @ admin @ c:irua:174380 |
Serial |
6691 |
Permanent link to this record |