Records |
Author |
Masir, M.R.; Vasilopoulos, P.; Peeters, F.M. |
Title |
Wavevector filtering through single-layer and bilayer graphene with magnetic barrier structures |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
93 |
Issue |
24 |
Pages |
242103,1-242103,3 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We show that the angular range of the transmission through magnetic barrier structures can be efficiently controlled in single-layer and bilayer graphenes and this renders the structures efficient wavevector filters. As the number of magnetic barriers increases, this range shrinks, the gaps in the transmission versus energy become wider, and the conductance oscillates with the Fermi energy. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000261896400032 |
Publication Date |
2008-12-15 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
91 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.411; 2008 IF: 3.726 |
Call Number |
UA @ lucian @ c:irua:75931 |
Serial |
3910 |
Permanent link to this record |
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|
|
Author |
Li, L.L.; Moldovan, D.; Vasilopoulos, P.; Peeters, F.M. |
Title |
Aharonov-Bohm oscillations in phosphorene quantum rings |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
95 |
Issue |
20 |
Pages |
205426 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The Aharonov-Bohm (AB) effect in square phosphorene quantum rings, with armchair and zigzag edges, is investigated using the tight-binding method. The energy spectra and wave functions of such rings, obtained as a function of the magnetic flux Phi threading the ring, are strongly influenced by the ringwidthW, an in-plane electric field E-p, and a side-gating potential V-g. Compared to a square dot, the ring shows an enhanced confinement due to its inner edges and an interedge coupling along the zigzag direction, both of which strongly affect the energy spectrum and the wave functions. The energy spectrum that is gapped consists of a regular part, of conduction (valence) band states, that shows the usual AB oscillations in the higher-(lower-) energy region, and of edge states, in the gap, that exhibit no AB oscillations. As the width W decreases, the AB oscillations become more distinct and regular and their period is close to Phi(0)/2, where the flux quantum Phi(0) = h/e is the period of an ideal circular ring (W -> 0). Both the electric field E-p and the side-gating potential V-g reduce the amplitude of the AB oscillations. The amplitude can be effectively tuned by E-p or V-g and exhibits an anisotropic behavior for different field directions or side-gating configurations. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
Language |
|
Wos |
000402003700010 |
Publication Date |
2017-05-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
16 |
Open Access |
|
Notes |
; This work was financially supported by the Chinese Academy of Sciences, the Flemish Science Foundation (FWO-V1), and by the Canadian NSERC Grant No. OGP0121756 (P.V.). ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:144267 |
Serial |
4638 |
Permanent link to this record |
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|
|
Author |
Van Pottelberge, R.; Zarenia, M.; Vasilopoulos, P.; Peeters, F.M. |
Title |
Graphene quantum dot with a Coulomb impurity : subcritical and supercritical regime |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
Volume |
95 |
Issue |
24 |
Pages |
245410 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We study the influence of confinement on the atomic collapse due to a Coulomb impurity placed at the center of a graphene quantum dot of radius R. We apply the zigzag or infinite-mass boundary condition and consider both a point-size and a finite-size impurity. As a function of the impurity strength Za, the energy spectra are discrete. In the case of the zigzag boundary condition, the degenerate (with respect to the angular momentum m) zero-energy levels are pulled down in energy as Z alpha increases, and they remain below epsilon = – Z alpha. Our results show that the energy levels exhibit a 1/R dependence in the subcritical regime [Z alpha < |km + 1/2|, k = 1 (-1) for the K (K') valley]. In the supercritical regime (Z alpha > |km + 1/2|) we find a qualitatively very different behavior where the levels decrease as a function of R in a nonmonotonic manner. While the valley symmetry is preserved in the presence of the impurity, we find that the impurity breaks electron-hole symmetry. We further study the energy spectrum of zigzag quantum dots in gapped graphene. Our results show that as the gap increases, the lowest electron states are pushed into the gap by the impurity. |
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 |
|
Language |
|
Wos |
000403072400005 |
Publication Date |
2017-06-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
Notes |
; We thank Massoud Ramezani-Masir and Dean Moldovan for fruitful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the Methusalem funding of the Flemish Government, and by the Canadian NSERC Grant No. OGP0121756 (P. V.). ; |
Approved |
Most recent IF: 3.836 |
Call Number |
UA @ lucian @ c:irua:144197 |
Serial |
4661 |
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 |
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 |
|
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 |
|
Series Issue |
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Edition |
|
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
|
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 |
Vasilopoulos, P.; Wang, X.F.; Peeters, F.M.; Chowdhury, S.; Long, A.R.; Davies, J.H. |
Title |
Magneto resistance oscillations in a modulated 2DEG periodic in the ratio h/e to flux per unit cell |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Physica. E: Low-dimensional systems and nanostructures
T2 – 15th International Conference on Electronic Properties of, Two-Dimensional Systems (EP2DS-15), JUL 14-18, 2003, Nara, JAPAN |
Abbreviated Journal |
Physica E |
Volume |
22 |
Issue |
1-3 |
Pages |
389-393 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Transport properties of the 2DEG are studied in the presence of a normal magnetic field B and of a weak, two-dimensional periodic potential modulation. A tight-binding treatment has shown that each Landau level splits into several subbands with exponentially small gaps between them. Assuming the latter are closed due to disorder gives analytical wave functions and simplifies the evaluation of the magnetoresistance tensor p(muv) The relative phase of the oscillations in p(xx) and p(yy) depends on the modulation strengths and periods. For short periods less than or equal to 100 nm, in addition to the Weiss oscillations, the collisional contribution to the conductivity and the corresponding resistivity contribution show prominent peaks when one flux quantum h/e passes through an integral number of unit cells in good agreement with experiments. For periods 300-400 nm long used in early experiments, these peaks occur at fields 10-25 times smaller than those of the Weiss oscillations and are not resolved. (C) 2003 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
North-Holland |
Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000221140800094 |
Publication Date |
2004-02-10 |
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 |
1386-9477; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
2.221 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.221; 2004 IF: 0.898 |
Call Number |
UA @ lucian @ c:irua:104107 |
Serial |
1911 |
Permanent link to this record |
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Author |
Dong, H.M.; Xu, W.; Zhang, J.; Peeters, F.M.; Vasilopoulos, P. |
Title |
Photo-excited carriers and optical conductance and transmission in graphene in the presence of phonon scattering |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
Physica E |
Volume |
42 |
Issue |
4 |
Pages |
748-750 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
We present a theoretical study of the optoelectronic properties of monolayer graphene. Including the effect of the electron-photon-phonon scattering, we employ the mass- and energy-balance equations derived from the Boltzmann equation to evaluate self-consistently the carrier densities, optical conductance and transmission coefficient in graphene in the presence of linearly polarized radiation field. We find that the photo-excited carrier density can be increased under infrared radiation and depend strongly on radiation intensity and frequency. For short wavelengths (lambda <3 mu m), the universal optical conductance sigma(0) = e(2)/4h is obtained and the light transmittance is about 0.97-0.98. Interestingly, there is an optical absorption window in the range 4-100 mu m which is induced by different transition energies required for inter- and intra-band optical absorption. The position and width of this absorption window depend sensitively on temperature and carrier density of the system. These results are relevant for applications of recently developed graphene devices in advanced optoelectronics such as the infrared photodetectors. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
North-Holland |
Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000276541200022 |
Publication Date |
2009-11-25 |
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 |
|
ISSN |
1386-9477; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.221 |
Times cited |
7 |
Open Access |
|
Notes |
; ; |
Approved |
Most recent IF: 2.221; 2010 IF: 1.304 |
Call Number |
UA @ lucian @ c:irua:99216 |
Serial |
2607 |
Permanent link to this record |
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Author |
Xu, W.; Vasilopoulos, P.; Das, M.P.; Peeters, F.M. |
Title |
Self-consistent g* factor and spin-split Landau levels in strong magnetic fields and at low temperatures |
Type |
P3 Proceeding |
Year |
1995 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
743-746 |
Keywords |
P3 Proceeding; Condensed Matter Theory (CMT) |
Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
World Scientific |
Place of Publication |
Singapore |
Editor |
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Language |
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Wos |
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Publication Date |
0000-00-00 |
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 |
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ISBN |
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Additional Links |
UA library record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
MATERIALS SCIENCE, MULTIDISCIPLINARY 96/271 Q2 # |
Call Number |
UA @ lucian @ c:irua:12203 |
Serial |
2974 |
Permanent link to this record |