Records |
Author |
Kishore, V.V.R.; Partoens, B.; Peeters, F.M. |
Title |
Electronic structure of InAs/GaSb core-shell nanowires |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
16 |
Pages |
165439-7 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The electronic and optical properties of InAs/GaSb core-shell nanowires are investigated within the effective mass k . p approach. These systems have a broken band gap, which results in spatially separated confinement of electrons and holes. We investigated these structures for different sizes of the InAs and GaSb core and shell radius. We found that for certain configurations, the conduction band states penetrate into the valence band states resulting in a negative band gap (E-g < 0), which leads to a conduction band ground state that lies below the valence band ground state at the Gamma point. For certain core-shell wires, only one conduction band state penetrates into the valence band and in this case, a minigap Delta opens up away from the Gamma point and as a consequence the electronic properties of the nanowire now depend on both E-g and Delta values. |
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 |
000310131400005 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-10-23 |
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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
26 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:102164 |
Serial |
1014 |
Permanent link to this record |
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Author |
Vagov, A.; Shanenko, A.A.; Milošević, M.V.; Axt, V.M.; Peeters, F.M. |
Title |
Two-band superconductors : extended Ginzburg-Landau formalism by a systematic expansion in small deviation from the critical temperature |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
14 |
Pages |
144514 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We derive the extended Ginzburg-Landau (GL) formalism for a clean s-wave two-band superconductor by employing a systematic expansion of the free-energy functional and the corresponding matrix gap equation in powers of the small deviation from the critical temperature tau = 1 – T/T-c. The two lowest orders of this expansion produce the equation for T-c and the standard GL theory. It is shown that in agreement with previous studies, this two-band GL theory maps onto the single-band GL model and thus fails to describe the difference in the spatial profiles of the two-band condensates. We prove that this difference appears already in the leading correction to the standard GL theory, which constitutes the extended GL formalism. We derive linear differential equations that determine the leading corrections to the band order parameters and magnetic field, discuss the validity of these equations, and consider examples of an important interplay between the band condensates. Finally, we present numerical results for the thermodynamic critical magnetic field and temperature-dependent band gaps for recent materials of interest, which are in very good agreement with those obtained from the full BCS approach in a wide temperature range. To this end, we emphasize the advantages of our extended GL theory in comparison with the often used two-component GL-like model based on an unreconstructed two-band generalization of the Gor'kov derivation. |
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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 |
000309776800001 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-10-12 |
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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
44 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). Authors are indebted to Y. Singh and R. Prozorov for discussions and for providing recent experimental data. A. V. is grateful to W. Pesch for stimulating discussions and critical comments on this work. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:101798 |
Serial |
3769 |
Permanent link to this record |
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Author |
Carrillo-Nunez, H.; Magnus, W.; Vandenberghe, W.G.; Sorée, B.; Peeters, F.M. |
Title |
Phonon-assisted Zener tunneling in a p-n diode silicon nanowire |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Solid state electronics |
Abbreviated Journal |
Solid State Electron |
Volume |
79 |
Issue |
|
Pages |
196-200 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The Zener tunneling current flowing through a biased, abrupt p-n junction embedded in a cylindrical silicon nanowire is calculated. As the band gap becomes indirect for sufficiently thick wires, Zener tunneling and its related transitions between the valence and conduction bands are mediated by short-wavelength phonons interacting with mobile electrons. Therefore, not only the high electric field governing the electrons in the space-charge region but also the transverse acoustic (TA) and transverse optical (TO) phonons have to be incorporated in the expression for the tunneling current. The latter is also affected by carrier confinement in the radial direction and therefore we have solved the Schrodinger and Poisson equations self-consistently within the effective mass approximation for both conduction and valence band electrons. We predict that the tunneling current exhibits a pronounced dependence on the wire radius, particularly in the high-bias regime. (C) 2012 Elsevier Ltd. All rights reserved. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Oxford |
Editor |
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Language |
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Wos |
000313611000037 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-09-29 |
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 |
|
Edition |
|
ISSN |
0038-1101; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.58 |
Times cited |
2 |
Open Access |
|
Notes |
; This work is supported by the Flemish Science Foundation (FWO-VI), and the Interuniversity Attraction Poles, Belgium State, Belgium Science Policy, and IMEC. One of the authors (W. Vandenberghe) gratefully acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). ; |
Approved |
Most recent IF: 1.58; 2013 IF: 1.514 |
Call Number |
UA @ lucian @ c:irua:110104 |
Serial |
2600 |
Permanent link to this record |
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Author |
Badalyan, S.M.; Peeters, F.M. |
Title |
Enhancement of Coulomb drag in double-layer graphene structures by plasmons and dielectric background inhomogeneity |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
12 |
Pages |
121405 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The drag of massless fermions in graphene double-layer structures is investigated over a wide range of temperatures and interlayer separations. We show that the inhomogeneity of the dielectric background in such graphene structures, for experimentally relevant parameters, results in a significant enhancement of the drag resistivity. At intermediate temperatures the dynamical screening via plasmon-mediated drag enhances the drag resistivity and results in an upturn in its behavior at large interlayer separations. In a range of interlayer separations, corresponding to the crossover from strong to weak coupling of graphene layers, we find that the decrease of the drag resistivity with interlayer spacing is approximately quadratic. This dependence weakens below this range of interlayer spacing while for larger separations we find a cubic (quartic) dependence at intermediate (low) temperatures. |
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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 |
000309178100003 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-09-21 |
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 |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
|
Notes |
; We acknowledge support from the Flemisch Science Foundation (FWO-Vl) and the Belgian Science Policy (BELSPO). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:101834 |
Serial |
1060 |
Permanent link to this record |
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Author |
Nowak, M.P.; Szafran, B.; Peeters, F.M. |
Title |
Resonant harmonic generation and collective spin rotations in electrically driven quantum dots |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
12 |
Pages |
125428 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Spin rotations induced by an ac electric field in a two-electron double quantum dot are studied by an exact numerical solution of the time-dependent Schrodinger equation in the context of recent electric-dipole spin resonance experiments on gated nanowires. We demonstrate that the splitting of the main resonance line by the spin exchange coupling is accompanied by the appearance of fractional resonances and that both these effects are triggered by interdot tunnel coupling. We find that the ac-driven system generates residual but distinct harmonics of the driving frequency, which are amplified when tuned to the main transition frequency. The mechanism is universal for electron systems in electrically driven potentials and works also in the absence of electron-electron interaction or spin-orbit coupling. |
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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 |
000308867300005 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-09-21 |
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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
|
Notes |
; This work was supported by funds of the Ministry of Science and Higher Education (MNiSW) for 2012-2013 under Project No. IP2011038671, and by PL-Grid Infrastructure. M.P.N. gratefully acknowledges support from the Foundation for Polish Science (FNP) under START and MPD program cofinanced by the EU European Regional Development Fund. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:101839 |
Serial |
2885 |
Permanent link to this record |
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Author |
Moldovan, D.; Masir, M.R.; Covaci, L.; Peeters, F.M. |
Title |
Resonant valley filtering of massive Dirac electrons |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
11 |
Pages |
115431 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Electrons in graphene, in addition to their spin, have two pseudospin degrees of freedom: sublattice and valley pseudospin. Valleytronics uses the valley degree of freedom as a carrier of information similarly to the way spintronics uses electron spin. We show how a double-barrier structure consisting of electric and vector potentials can be used to filter massive Dirac electrons based on their valley index. We study the resonant transmission through a finite number of barriers and we obtain the energy spectrum of a superlattice consisting of electric and vector potentials. When a mass term is included, the energy bands and energy gaps at the K and K′ points are different and they can be tuned by changing the potential. |
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 |
000309173300004 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-09-21 |
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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
55 |
Open Access |
|
Notes |
This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro- GRAPHENE within the project CONGRAN, and the Flemish Science Foundation (FWO-Vl). |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:101835 |
Serial |
2896 |
Permanent link to this record |
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Author |
Euán-Díaz, E.C.; Misko, V.R.; Peeters, F.M.; Herrera-Velarde, S.; Castaneda-Priego, R. |
Title |
Single-file diffusion in periodic energy landscapes : the role of hydrodynamic interactions |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
Volume |
86 |
Issue |
3Part 1 |
Pages |
031123 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We report on the dynamical properties of interacting colloids confined to one dimension and subjected to external periodic energy landscapes. We particularly focus on the influence of hydrodynamic interactions on the mean-square displacement. Using Brownian dynamics simulations, we study colloidal systems with two types of repulsive interparticle interactions, namely, Yukawa and superparamagnetic potentials. We find that in the homogeneous case, hydrodynamic interactions lead to an enhancement of the particle mobility and the mean-square displacement at long times scales as t(alpha), with alpha = 1/2 + epsilon and epsilon being a small correction. This correction, however, becomes much more important in the presence of an external field, which breaks the homogeneity of the particle distribution along the line and, therefore, promotes a richer dynamical scenario due to the hydrodynamical coupling among particles. We provide here the complete dynamical scenario in terms of the external potential parameters: amplitude and commensurability. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
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Language |
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Wos |
000308873500002 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-09-21 |
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 |
1539-3755;1550-2376; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.366 |
Times cited |
14 |
Open Access |
|
Notes |
; This work was partially supported by the “Odysseus” Program of the Flemish Government, the Flemish Science Foundation (FWO-Vl), and PIFI 3.4-PROMEP and CONACyT (Grant Nos. 61418/2007 and 102339/2008, Ph.D. Scholarship No. 230171/ 2010). ; |
Approved |
Most recent IF: 2.366; 2012 IF: 2.313 |
Call Number |
UA @ lucian @ c:irua:101840 |
Serial |
3021 |
Permanent link to this record |
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Author |
da Costa, D.R.; Chaves, A.; Farias, G.A.; Covaci, L.; Peeters, F.M. |
Title |
Wave-packet scattering on graphene edges in the presence of a pseudomagnetic field |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
11 |
Pages |
115434 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The scattering of a Gaussian wave packet in armchair and zigzag graphene edges is theoretically investigated by numerically solving the time-dependent Schrodinger equation for the tight-binding model Hamiltonian. Our theory allows us to investigate scattering in reciprocal space, and depending on the type of graphene edge we observe scattering within the same valley, or between different valleys. In the presence of an external magnetic field, the well-known skipping orbits are observed. However, our results demonstrate that in the case of a pseudomagnetic field, induced by nonuniform strain, the scattering by an armchair edge results in a nonpropagating edge state. |
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 |
000309174100005 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-09-21 |
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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
28 |
Open Access |
|
Notes |
; Discussions with E. B. Barros are gratefully acknowledged. This work was supported by the Brazilian Council for Research (CNPq), the Flemish Science Foundation (FWO-Vl), the ESF-EuroGRAPHENE (project CONGRAN), and the bilateral program between Flanders and Brazil. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:101833 |
Serial |
3907 |
Permanent link to this record |
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Author |
Shanenko, A.A.; Croitoru, M.D.; Vagov, A.V.; Axt, V.M.; Perali, A.; Peeters, F.M. |
Title |
Atypical BCS-BEC crossover induced by quantum-size effects |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
Volume |
86 |
Issue |
3 |
Pages |
033612 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Quantum-size oscillations of the basic physical characteristics of a confined fermionic condensate are a well-known phenomenon. Its conventional understanding is based on the single-particle physics, whereby the oscillations follow variations in the single-particle density of states driven by the size quantization. Here we present a study of a cigar-shaped ultracold superfluid Fermi gas, which demonstrates an important many-body aspect of the quantum-size coherent effects, overlooked previously. The many-body physics is revealed here in the atypical crossover from the Bardeen-Cooper-Schrieffer (BCS) superfluid to the Bose-Einstein condensate (BEC) induced by the size quantization of the particle motion. The single-particle energy spectrum for the transverse dimensions is tightly bound, whereas for the longitudinal direction it resembles a quasi-free dispersion. This results in the formation of a series of single-particle subbands (shells) so that the aggregate fermionic condensate becomes a coherent mixture of subband condensates. Each time when the lower edge of a subband crosses the chemical potential, the BCS-BEC crossover is approached in this subband, and the aggregate condensate contains both BCS and BEC-like components. |
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 |
000308639500004 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-09-15 |
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 |
1050-2947;1094-1622; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.925 |
Times cited |
34 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). The authors thank C. Salomon and C. Vale for their valuable explications of the experimental situation and interest to our work. We are grateful to G. C. Strinati, D. Neilson, and P. Pieri for useful discussions. M. D. C. acknowledges support of the EU Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). A. P. gratefully acknowledges financial support of the European Science Foundation, POLATOM Research Networking Programme, Ref. No. 4844 for his visit to the University of Antwerp. A. A. S. acknowledges financial support of the European Science Foundation, POLATOM Research Networking Programme, Ref. No. 5200 for his visit to the University of Camerino. ; |
Approved |
Most recent IF: 2.925; 2012 IF: 3.042 |
Call Number |
UA @ lucian @ c:irua:101844 |
Serial |
203 |
Permanent link to this record |
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Author |
Szumniak, P.; Bednarek, S.; Partoens, B.; Peeters, F.M. |
Title |
Spin-orbit-mediated manipulation of heavy-hole spin qubits in gated semiconductor nanodevices |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
109 |
Issue |
10 |
Pages |
107201 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A novel spintronic nanodevice is proposed that is able to manipulate the single heavy-hole spin state in a coherent manner. It can act as a single quantum logic gate. The heavy-hole spin transformations are realized by transporting the hole around closed loops defined by metal gates deposited on top of the nanodevice. The device exploits Dresselhaus spin-orbit interaction, which translates the spatial motion of the hole into a rotation of the spin. The proposed quantum gate operates on subnanosecond time scales and requires only the application of a weak static voltage which allows for addressing heavy-hole spin qubits individually. Our results are supported by quantum mechanical time-dependent calculations within the four-band Luttinger-Kohn model. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000308295700015 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-09-05 |
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 |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
41 |
Open Access |
|
Notes |
; This work was supported by the Grant No. NN202 128337 from the Ministry of Science and Higher Education, as well as by the “Krakow Interdisciplinary PhD-Project in Nanoscience and Advances Nanostructures” operated within the Foundation for Polish Science MPD Programme and cofinanced by European Regional Development Fund, the Belgian Science Policy (IAP), and the Flemish Science Foundation (FWO-V1). ; |
Approved |
Most recent IF: 8.462; 2012 IF: 7.943 |
Call Number |
UA @ lucian @ c:irua:101849 |
Serial |
3094 |
Permanent link to this record |
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Author |
Zhang, L.-F.; Covaci, L.; Milošević, M.V.; Berdiyorov, G.R.; Peeters, F.M. |
Title |
Unconventional vortex states in nanoscale superconductors due to shape-induced resonances in the inhomogeneous Cooper-pair condensate |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
109 |
Issue |
10 |
Pages |
107001 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Vortex matter in mesoscopic superconductors is known to be strongly affected by the geometry of the sample. Here we show that in nanoscale superconductors with coherence length comparable to the Fermi wavelength the shape resonances of the order parameter results in an additional contribution to the quantum topological confinement-leading to unconventional vortex configurations. Our Bogoliubov-de Gennes calculations in a square geometry reveal a plethora of asymmetric, giant multivortex, and vortex-antivortex structures, stable over a wide range of parameters and which are very different from those predicted by the Ginzburg-Landau theory. These unconventional states are relevant for high-T-c nanograins, confined Bose-Einstein condensates, and graphene flakes with proximity-induced superconductivity. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000308295700014 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-09-05 |
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 |
0031-9007;1079-7114; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
31 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen). ; |
Approved |
Most recent IF: 8.462; 2012 IF: 7.943 |
Call Number |
UA @ lucian @ c:irua:101850 |
Serial |
3801 |
Permanent link to this record |
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Author |
Zarenia, M.; Leenaerts, O.; Partoens, B.; Peeters, F.M. |
Title |
Substrate-induced chiral states in graphene |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
8 |
Pages |
085451 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Unidirectional chiral states are predicted in single layer graphene which originate from the breaking of the sublattice symmetry due to an asymmetric mass potential. The latter can be created experimentally using boron-nitride (BN) substrates with a line defect (B-B or N-N) that changes the induced mass potential in graphene. Solving the Dirac-Weyl equation, the obtained energy spectrum is compared with the one calculated using ab initio density functional calculations. We found that these one-dimensional chiral states are very robust and they can even exist in the presence of a small gap between the mass regions. In the latter case additional bound states are found that are topologically different from those chiral states. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
|
Editor |
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Language |
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Wos |
000308005600015 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-08-28 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
41 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), and the European Science Foundation (ESF) under the EUROCORES Program: EuroGRAPHENE (project CONGRAN). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:101100 |
Serial |
3347 |
Permanent link to this record |
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|
|
Author |
Sivek, J.; Leenaerts, O.; Partoens, B.; Peeters, F.M. |
Title |
First-principles investigation of bilayer fluorographene |
Type |
A1 Journal article |
Year |
2012 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
Volume |
116 |
Issue |
36 |
Pages |
19240-19245 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Ab initio calculations within the density functional theory formalism are performed to investigate the stability and electronic properties of fluorinated bilayer graphene (bilayer fluorographene). A comparison is made to previously investigated graphane, bilayer graphane, and fluorographene. Bilayer fluorographene is found to be a much more stable material than bilayer graphane. Its electronic band structure is similar to that of monolayer fluorographene, but its electronic band gap is significantly larger (about 1 eV). We also calculate the effective masses around the Gamma-point for fluorographene and bilayer fluorographene and find that they are isotropic, in contrast to earlier reports. Furthermore, it is found that bilayer fluorographene is almost as strong as graphene, as its 2D Young's modulus is approximately 300 N m(-1). |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
|
Language |
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Wos |
000308631300022 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-08-21 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.536 |
Times cited |
39 |
Open Access |
|
Notes |
; This work is supported by the ESF-Eurocores program EuroGRAPHENE (project CONERAN) and the Flemish Science Foundation (FWO-V1). ; |
Approved |
Most recent IF: 4.536; 2012 IF: 4.814 |
Call Number |
UA @ lucian @ c:irua:101842 |
Serial |
1211 |
Permanent link to this record |
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|
|
Author |
Sena, S.H.R.; Pereira, J.M.; Farias, G.A.; Peeters, F.M.; Costa Filho, R.N. |
Title |
The electronic properties of graphene and graphene ribbons under simple shear strain |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
24 |
Issue |
37 |
Pages |
375301 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A tight-binding model is used to study the energy band of graphene and graphene ribbon under simple shear strain. The ribbon consists of lines of carbon atoms in an armchair or zigzag orientation where a simple shear strain is applied in the x-direction keeping the atomic distances in the y-direction unchanged. Such modification in the lattice gives an energy band that differs in several aspects from the one without any shear and with pure shear. The changes in the spectrum depend on the line displacement of the ribbon, and also on the modified hopping parameter. It is also shown that this simple shear strain tunes the electronic properties of both graphene and graphene ribbon, opening and closing energy gaps for different displacements of the system. The modified density of states is also shown. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000308202700011 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-08-14 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
15 |
Open Access |
|
Notes |
; This work was supported by CNPq (RNCF), the National Council for the Improvement of Higher Education (CAPES), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the bilateral program between Flanders and Brazil. ; |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
Call Number |
UA @ lucian @ c:irua:101838 |
Serial |
1000 |
Permanent link to this record |
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|
Author |
Sena, S.H.R.; Pereira, J.M.; Farias, G.A.; Peeters, F.M. |
Title |
Cyclotron resonance of trilayer graphene |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
8 |
Pages |
085412 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The cyclotron resonance energies, the corresponding oscillator strengths, and the cyclotron absorption spectrum for trilayer graphene are calculated for both ABA and ABC stacking. A gate potential across the stacked layers leads to (1) a reduction of the transition energies, (2) a lifting of the degeneracy of the zero Landau level, and (3) the removal of the electron-hole symmetry. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
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Wos |
000307273100009 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-08-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
|
Notes |
; This work was supported by the National Council for the Improvement of Higher education (CAPES), the Brazilian Council for Research (CNPq), the Flemish Science Foundation (FWO-V1), the bilateral projects between Flanders and Brazil and the CNPq and FWO-V1, and the ESF-Eurographene project CONGRAN. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:100815 |
Serial |
604 |
Permanent link to this record |
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Author |
Xiao, Y.M.; Xu, W.; Zhang, Y.Y.; Peeters, F.M. |
Title |
Optoelectronic properties of ABC-stacked trilayer graphene |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Physica status solidi: B: basic research |
Abbreviated Journal |
Phys Status Solidi B |
Volume |
250 |
Issue |
1 |
Pages |
86-94 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We present a theoretical study on the optoelectronic properties of ABC-stacked trilayer graphene (TLG). The optical conductance and light transmittance are evaluated through using the energy-balance equation derived from the Boltzmann equation for an air/graphene/dielectric-wafer system in the presence of linearly polarized radiation field. The results obtained from two band structure models are examined and compared. For short wavelength radiation, the universal optical conductance sigma(0) = 3e(2)/(4h) can be obtained. Importantly, there exists an optical absorption window in the radiation wavelength range 10-200 mu m, which is induced by different transition energies required for inter- and intra-band optical absorption channels. As a result, we find that the position and width of this window depend sensitively on temperature and carrier density of the system, especially the lower frequency edge. There is a small characteristic absorption peak at about 82 mu m where the largest interband transition states exist in the ABC-stacked TLG model, in contrast to the relatively smooth curves in a simplified model. These theoretical results indicate that TLG has some interesting and important physical properties which can be utilized to realize infrared or THz optoelectronic devices. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Berlin |
Editor |
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Language |
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Wos |
000313347500011 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-08-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0370-1972; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.674 |
Times cited |
6 |
Open Access |
|
Notes |
; This work was supported by the National Natural Science Foundation of China (grant no. 10974206), Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. One of us (F.M.P.) was a Specially Appointed Foreign Professor of the Chinese Academy of Sciences. ; |
Approved |
Most recent IF: 1.674; 2013 IF: 1.605 |
Call Number |
UA @ lucian @ c:irua:110109 |
Serial |
2495 |
Permanent link to this record |
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Author |
Matulis, A.; Masir, M.R.; Peeters, F.M. |
Title |
Scattering of a Dirac electron on a mass barrier |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
Volume |
86 |
Issue |
2 |
Pages |
022101 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The interaction of a wave packet (and in particular the wave front) with a mass barrier is investigated in one dimension. We discuss the main features of the wave packet that are inherent to two-dimensional wave packets, such as compression during reflection, penetration in the case when the energy is lower than the height of the barrier, waving tails, precursors, and the retardation of the reflected and penetrated wave packets. These features depend on the wave-packet envelope function which we demonstrate by considering the case of a rectangular wave packet with sharp front and trailing edges and a smooth Gaussian wave packet. The method of Fourier integral for obtaining the nonstationary solutions is used. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
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Wos |
000306991200001 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-08-01 |
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 |
1050-2947;1094-1622; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.925 |
Times cited |
9 |
Open Access |
|
Notes |
; This research was supported by the Flemish Science Foundation (FWO-Vl) and (in part) by the Lithuanian Science Council under Project No. MIP-79/2010. ; |
Approved |
Most recent IF: 2.925; 2012 IF: 3.042 |
Call Number |
UA @ lucian @ c:irua:100822 |
Serial |
2948 |
Permanent link to this record |
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Author |
Berdiyorov, G.R.; Milošević, M.V.; Latimer, M.L.; Xiao, Z.L.; Kwok, W.K.; Peeters, F.M. |
Title |
Large magnetoresistance oscillations in mesoscopic superconductors due to current-excited moving vortices |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
Volume |
109 |
Issue |
5 |
Pages |
057004 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We show in the case of a superconducting Nb ladder that a mesoscopic superconductor typically exhibits magnetoresistance oscillations whose amplitude and temperature dependence are different from those stemming from the Little-Parks effect. We demonstrate that these large resistance oscillations (as well as the monotonic background on which they are superimposed) are due to current-excited moving vortices, where the applied current in competition with the oscillating Meissner currents imposes or removes the barriers for vortex motion in an increasing magnetic field. Because of the ever present current in transport measurements, this effect should be considered in parallel with the Little-Parks effect in low-critical temperature (T-c) samples, as well as with recently proposed thermal activation of dissipative vortex-antivortex pairs in high-T-c samples. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000306994900024 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-07-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007;1079-7114; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.462 |
Times cited |
65 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP) (theory) and by the U. S. Department of Energy (DOE) Award No. DE-FG02-06ER46334 (experiment). G. R. B. acknowledges individual grant from FWO-Vl. W. K. K. acknowledges support from DOE BES under Contract No. DE-AC02-06CH11357, which also funds Argonne's Center for Nanoscale Materials (CNM) where the focused-ion-beam milling was performed. ; |
Approved |
Most recent IF: 8.462; 2012 IF: 7.943 |
Call Number |
UA @ lucian @ c:irua:100832 |
Serial |
1780 |
Permanent link to this record |
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Author |
Costamagna, S.; Neek-Amal, M.; Los, J.H.; Peeters, F.M. |
Title |
Thermal rippling behavior of graphane |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
4 |
Pages |
041408-4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Thermal fluctuations of single layer hydrogenated graphene (graphane) are investigated using large scale atomistic simulations. By analyzing the mean square value of the height fluctuations < h(2)> and the height-height correlation function H(q) for different system sizes and temperatures, we show that hydrogenated graphene is an unrippled system in contrast to graphene. The height fluctuations are bounded, which is confirmed by a H(q) tending to a constant in the long wavelength limit instead of showing the characteristic scaling law q(4-eta)(eta similar or equal to 0.85) predicted by membrane theory. This unexpected behavior persists up to temperatures of at least 900 K and is a consequence of the fact that in graphane the thermal energy can be accommodated by in-plane bending modes, i.e., modes involving C-C-C bond angles in the buckled carbon layer, instead of leading to significant out-of-plane fluctuations that occur in graphene. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000306649200002 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-07-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
46 |
Open Access |
|
Notes |
; We thank A. Fasolino, A. Dobry, and K. H. Michel for their useful comments. S.C. is supported by the Belgian Science Foundation (BELSPO). This work is supported by the ESF-EuroGRAPHENE project CONGRAN and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:100840 |
Serial |
3630 |
Permanent link to this record |
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Author |
Neek-Amal, M.; Covaci, L.; Peeters, F.M. |
Title |
Nanoengineered nonuniform strain in graphene using nanopillars |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
86 |
Issue |
4 |
Pages |
041405 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Recent experiments showed that nonuniform strain can be produced by depositing graphene over pillars. We employed atomistic calculations to study the nonuniform strain and the induced pseudomagnetic field in graphene on top of nanopillars. By decreasing the distance between the nanopillars a complex distribution for the pseudomagnetic field can be generated. Furthermore, we performed tight-binding calculations of the local density of states (LDOS) by using the relaxed graphene configuration obtained from atomistic calculations. We find that the quasiparticle LDOS are strongly modified near the pillars, both at low energies showing sublattice polarization and at high energies showing shifts of the van Hove singularity. Our study shows that changing the specific pattern of the nanopillars allows us to create a desired shape of the pseudomagnetic field profile while the LDOS maps provide an input for experimental verification by scanning tunneling microscopy. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000306313900001 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-07-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
51 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-V1) and the EuroGRAPHENE project CONGRAN. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:100765 |
Serial |
2255 |
Permanent link to this record |
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Author |
Berdiyorov, G.R.; Milošević, M.V.; Peeters, F.M. |
Title |
Spatially dependent sensitivity of superconducting meanders as single-photon detectors |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
100 |
Issue |
26 |
Pages |
262603 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The photo-response of a thin current-carrying superconducting stripe with a 90 degrees turn is studied within the time-dependent Ginzburg-Landau theory. We show that the photon acting near the inner corner (where the current density is maximal due to the current crowding [J. R. Clem and K. K. Berggren, Phys. Rev. B 84, 174510 (2011)]) triggers the nucleation of superconducting vortices at currents much smaller than the expected critical one, but does not bring the system to a higher resistive state and thus remains undetected. The transition to the resistive state occurs only when the photon hits the stripe away from the corner due to there uniform current distribution across the sample, and dissipation is due to the nucleation of a kinematic vortex-antivortex pair near the photon incidence. We propose strategies to account for this problem in the measurements. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4731627] |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
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Wos |
000305831500057 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-06-28 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
|
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 |
27 |
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI). G. R. B. acknowledges individual support from FWO-VI. ; |
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
Call Number |
UA @ lucian @ c:irua:100336 |
Serial |
3066 |
Permanent link to this record |
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|
|
Author |
Zhao, H.J.; Misko, V.R.; Peeters, F.M. |
Title |
Analysis of pattern formation in systems with competing range interactions |
Type |
A1 Journal article |
Year |
2012 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
Volume |
14 |
Issue |
|
Pages |
063032 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We analyzed pattern formation and identified various morphologies in a system of particles interacting through a non-monotonic potential with a competing range interaction characterized by a repulsive core (r < r(c)) and an attractive tail (r > r(c)), using molecular-dynamics simulations. Depending on parameters, the interaction potential models the inter-particle interaction in various physical systems ranging from atoms, molecules and colloids to vortices in low kappa type-II superconductors and in recently discovered 'type-1.5' superconductors. We constructed a 'morphology diagram' in the plane 'critical radius r(c)-density n' and proposed a new approach to characterizing the different types of patterns. Namely, we elaborated a set of quantitative criteria in order to identify the different pattern types, using the radial distribution function (RDF), the local density function and the occupation factor. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Bristol |
Editor |
|
Language |
|
Wos |
000306946600003 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-06-25 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1367-2630; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.786 |
Times cited |
45 |
Open Access |
|
Notes |
; We acknowledge useful discussions with Ernst Helmut Brandt, Charles Reichhardt and Cynthia Olson Reichhardt. This work was supported by the 'Odysseus' Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.786; 2012 IF: 4.063 |
Call Number |
UA @ lucian @ c:irua:101140 |
Serial |
102 |
Permanent link to this record |
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|
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Author |
Croitoru, M.D.; Shanenko, A.A.; Kaun, C.C.; Peeters, F.M. |
Title |
Ultra-small metallic grains : effect of statistical fluctuations of the chemical potential on superconducting correlations and vice versa |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
24 |
Issue |
27 |
Pages |
275701 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Superconducting correlations in an isolated metallic grain are governed by the interplay between two energy scales: the mean level spacing delta and the bulk pairing gap Delta(0), which are strongly influenced by the position of the chemical potential with respect to the closest single-electron level. In turn superconducting correlations affect the position of the chemical potential. Within the parity projected BCS model we investigate the probability distribution of the chemical potential in a superconducting grain with randomly distributed single-electron levels. Taking into account statistical fluctuations of the chemical potential due to the pairing interaction, we find that such fluctuations have a significant impact on the critical level spacing delta(c) at which the superconducting correlations cease: the critical ratio delta(c)/Delta(0) at which superconductivity disappears is found to be increased. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000305653100012 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-06-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
9 |
Open Access |
|
Notes |
; This work was supported by the European Community under the Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF network INSTANS. MDC and AAS are grateful to A Vagov for stimulating discussions. ; |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
Call Number |
UA @ lucian @ c:irua:100280 |
Serial |
3793 |
Permanent link to this record |
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Author |
Čukarić, N.; Arsoski, V.; Tadić, M.; Peeters, F.M. |
Title |
Hole states in nanocups in a magnetic field |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
23 |
Pages |
235425-235425,11 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The magnetic-field dependence of the hole states in a nanocup, which is composed of a ring (the nanocup rim) that surrounds a disk (the nanocup bottom), is obtained within the Luttinger-Kohn model for the unstrained GaAs/(Al,Ga) As and the strained (In,Ga) As/GaAs systems. Aharonov-Bohm oscillations due to angular momentum transitions of the hole ground state appear with periods that vary with the thickness of the disk. The strain in the (In, Ga) As/GaAs nanocup is sensitive to the disk thickness and favors the spatial localization of the heavy holes inside the disk. Therefore, the angular momentum transitions between the valence-band states disappear for much thinner disks than in the case of the unstrained GaAs/(Al, Ga) As nanocups. In both systems, the oscillations in the energy of the hole ground state are found to disappear for thinner inner layer than in the electron ground-state energy. This is due to the different confining potentials and the mixing between the heavy- and light-hole states. As a consequence, magnetization of the single hole is found to strongly depend on the bottom thickness of the strained (In, Ga) As/GaAs nanocup. Furthermore, we found that the strain can lead to a spatial separation of the electron and the hole, as in type-II band alignment, which is advantageous for the appearance of the excitonic Aharonov-Bohm effect. |
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Wos |
000305116700005 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-06-14 |
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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
4 |
Open Access |
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Notes |
; The authors thank B. Partoens for useful discussions. This work was supported by the EU NoE: SANDiE, the Ministry of Education and Science of Serbia, and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:98906 |
Serial |
1477 |
Permanent link to this record |
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Author |
Zarenia, M.; Vasilopoulos, P.; Peeters, F.M. |
Title |
Magnetotransport in periodically modulated bilayer graphene |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
24 |
Pages |
245426-245426,10 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Magnetotransport in bilayer graphene in the presence of a weak and periodic potential is investigated in the presence of a perpendicular magnetic field B. The modulation broadens the Landau levels into bands and for weak magnetic fields leads to the well-known Weiss oscillations in their bandwidth and their transport coefficients at very low B and to the Shubnikov-de Haas oscillations at larger B. The amplitude of the Weiss oscillations is severely reduced if the periodic potentials applied to the two layers oscillate out of phase. We also contrast some results with those corresponding to single-layer graphene. Relative to them the flat-band condition and the oscillation amplitude differ substantially, due to the interlayer coupling, and agree only when this coupling is extremely weak. We further show that the Hall conductivity exhibits the well-known steps at half-integer and integer multiples of 4e(2)/h in single-layer and bilayer graphene, respectively, even for very weak magnetic fields. The results are pertinent to weak and periodic corrugations when the potential modulation dominates the strain-induced magnetic modulation. |
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Wos |
000305253600012 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-06-14 |
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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES program EuroGRAPHENE (project CON-GRAN), and the Canadian NSERC Grant No. OGP0121756. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:99077 |
Serial |
1934 |
Permanent link to this record |
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Author |
Chen, Y.; Shanenko, A.A.; Peeters, F.M. |
Title |
Superconducting transition temperature of Pb nanofilms : impact of thickness-dependent oscillations of the phonon-mediated electron-electron coupling |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
22 |
Pages |
224517-224517,6 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
To date, several experimental groups reported measurements of the thickness dependence of T-c of atomically uniform single-crystalline Pb nanofilms. The reported amplitude of the T-c oscillations varies significantly from one experiment to another. Here we propose that the reason for this unresolved issue is an interplay of the quantum-size variations in the single-electron density of states with thickness-dependent oscillations in the phonon-mediated electron-electron coupling. Such oscillations in the coupling depend on the substrate material, the quality of the interface, the protection cover, and other details of the fabrication process, changing from one experiment to another. This explains why the available data do not exhibit one-voice consistency about the amplitude of the T-c oscillations. Our analyses are based on a numerical solution of the Bogoliubov-de Gennes equations for a superconducting slab. |
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Wos |
000305251300006 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-06-14 |
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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
24 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:99076 |
Serial |
3368 |
Permanent link to this record |
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Author |
Costamagna, S.; Schulz, A.; Covaci, L.; Peeters, F. |
Title |
Partially unzipped carbon nanotubes as magnetic field sensors |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
100 |
Issue |
23 |
Pages |
232104-232104,3 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The conductance through graphene nanoribbons (GNR) connected to a partially unzipped carbon nanotube (CNT) is studied in the presence of an external magnetic field applied parallel to the long axis of the tube by means of non-equilibrium Green's function technique. We consider CNTs that are partially unzipped to form armchair-GNR/zigzag-CNT/armchair-GNR or zigzag-GNR/armchair-CNT/zigzag-GNR junctions. We find that the inclusion of a longitudinal magnetic field affects the electronic states only in the CNT region, leading to the suppression of the conductance at low energies. We demonstrate that both types of junctions can be used as magnetic field sensors. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4726039] |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000305089900038 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-06-07 |
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 |
0003-6951; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
10 |
Open Access |
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Notes |
; L.C. acknowledges support from the Flemish Science Foundation (FWO-Vl) and S.C. from the Belgian Science Foundation (BELSPO). This work is supported by the ESF-EuroGRAPHENE Project CONGRAN. ; |
Approved |
Most recent IF: 3.411; 2012 IF: 3.794 |
Call Number |
UA @ lucian @ c:irua:99083 |
Serial |
2556 |
Permanent link to this record |
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Author |
Chen, Y.; Shanenko, A.A.; Croitoru, M.D.; Peeters, F.M. |
Title |
Quantum cascades in nano-engineered superconductors : geometrical, thermal and paramagnetic effects |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
24 |
Issue |
26 |
Pages |
265702 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The effect of a parallel magnetic field on the orbital motion of electrons in high-quality superconducting nanowires resulting in a superconductor-to-normal transition which occurs through a cascade of jumps in the order parameter as a function of the magnetic field. Such cascades originate from the transverse size quantization that splits the conduction band into a series of subbands. Here, based on a numerical solution of the Bogoliubov-de Gennes equations for a hollow nanocylinder, we investigate how the quantum-size cascades depend on the confining geometry, i.e., by changing the cylinder radius R and its thickness d we cover the range from the nanowire-like to the nanofilm-like regime. The cascades are shown to become much less pronounced when increasing R/d, i.e., when the nanofilm-like regime is approached. When the temperature is non-zero they are thermally smoothed. This includes the spin-magnetic-field interaction which reduces the critical (depairing) parallel magnetic field H-c,H-parallel to but does not have any qualitative effect on the quantum cascades. From our calculations it is seen that the paramagnetic limiting field H-par significantly exceeds H-c,H-parallel to even in extremely narrow nanocylinders, i.e., when R, d are down to a few nanometers, and H-c,H-parallel to is only about 10% larger when switching-off the spin-magnetic-field interaction in this case. Both characteristic fields, H-c,H-parallel to and H-par, exhibit pronounced quantum-size oscillations. We demonstrate that the quantum cascades and the quantum-size oscillations survive in the presence of surface roughness. |
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Place of Publication |
London |
Editor |
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Wos |
000305640800014 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-06-07 |
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 |
0953-8984;1361-648X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
6 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI) and the ESF-AQDJJ network. MDC acknowledges the support of the EU Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). ; |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
Call Number |
UA @ lucian @ c:irua:100281 |
Serial |
2773 |
Permanent link to this record |
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Author |
Krstajić, P.M.; Peeters, F.M. |
Title |
Energy-momentum dispersion relation of plasmarons in graphene |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
20 |
Pages |
205454-205454,4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The many-body correction to the band structure of a quasi-free-standing graphene layer is obtained within the Overhauser approach, where the electron-plasmon interaction is described as a field theoretical problem. We find that the Dirac-like spectrum is shifted by Delta E(k = 0), which is on the order of 50-150 meV, depending on the electron concentration n(e), and is in semiquantitative agreement with experimental data. The value of the Fermi velocity is renormalized by several percents and decreases with increasing electron concentration as found experimentally. |
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Wos |
000304649900004 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-06-05 |
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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the ESF-EuroGRAPHENE project CON-GRAN, and the Serbian Ministry of Education and Science (project No. TR 32008). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number |
UA @ lucian @ c:irua:98937 |
Serial |
1043 |
Permanent link to this record |
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Author |
Ramos, I.R.O.; Ferreira, W.P.; Munarin, F.F.; Farias, G.A.; Peeters, F.M. |
Title |
Bilayer crystals of charged magnetic dipoles : structure and phonon spectrum |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : E : statistical, nonlinear, and soft matter physics |
Abbreviated Journal |
Phys Rev E |
Volume |
85 |
Issue |
5:1 |
Pages |
051404-051404,12 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We study the structure and phonon spectrum of a two-dimensional bilayer system of classical charged dipoles oriented perpendicular to the plane of the layers for equal density in each layer. This system can be tuned through six different crystalline phases by changing the interlayer separation or the charge and/or dipole moment of the particle. The presence of the charge on the dipole particles is responsible for the nucleation of five staggered phases and a disordered phase which are not found in the magnetic dipole bilayer system. These extra phases are a consequence of the competition between the repulsive Coulomb and the attractive dipole interlayer interaction. We present the phase diagram and determine the order of the phase transitions. The phonon spectrum of the system was calculated within the harmonic approximation, and a nonmonotonic behavior of the phonon spectrum is found as a function of the effective strength of the interparticle interaction. The stability of the different phases is determined. |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
Woodbury (NY) |
Editor |
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Language |
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Wos |
000304403400002 |
Publication Date ![sorted by Publication Date field, descending order (down)](img/sort_desc.gif) |
2012-05-30 |
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 |
1539-3755;1550-2376; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.366 |
Times cited |
8 |
Open Access |
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Notes |
; This work was supported by the Brazilian agencies CNPq, CAPES, and FUNCAP (PRONEX grant), the Flemish Science Foundation (FWO-Vl), the bilateral program between Flanders and Brazil, and the CNPq-FWO collaborating project. The authors are grateful to Prof. G. Goldoni for some technical clarifications concerning Ref. [18]. ; |
Approved |
Most recent IF: 2.366; 2012 IF: 2.313 |
Call Number |
UA @ lucian @ c:irua:98940 |
Serial |
233 |
Permanent link to this record |