| Records |
| Author |
de Sousa, A.A.; Chaves, A.; Pereira, T.A.S.; Farias, G.A.; Peeters, F.M. |
| Title |
Quantum tunneling between bent semiconductor nanowires |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
118 |
Issue |
118 |
Pages |
174301 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We theoretically investigate the electronic transport properties of two closely spaced L-shaped semiconductor quantum wires, for different configurations of the output channel widths as well as the distance between the wires. Within the effective-mass approximation, we solve the time-dependent Schrodinger equation using the split-operator technique that allows us to calculate the transmission probability, the total probability current, the conductance, and the wave function scattering between the energy subbands. We determine the maximum distance between the quantum wires below which a relevant non-zero transmission is still found. The transmission probability and the conductance show a strong dependence on the width of the output channel for small distances between the wires. (C) 2015 AIP Publishing LLC. |
| 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 |
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| Language |
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Wos |
000364584200020 |
Publication Date |
2015-11-02 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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ISSN  |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.068 |
Times cited |
7 |
Open Access |
|
| Notes |
; A. A. Sousa was financially supported by CAPES, under the PDSE Contract No. BEX 7177/13-5. T. A. S. Pereira was financially supported by PRONEX/CNPq/FAPEMAT 850109/2009 and by CAPES under process BEX 3299/13-9. This work was financially supported by PRONEX/CNPq/FUNCAP, the Science Without Borders program and the bilateral project CNPq-FWO. ; |
Approved |
Most recent IF: 2.068; 2015 IF: 2.183 |
| Call Number |
UA @ lucian @ c:irua:129544 |
Serial |
4234 |
| Permanent link to this record |
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| Author |
Frota, D.A.; Chaves, A.; Ferreira, W.P.; Farias, G.A.; Milošević, M.V. |
| Title |
Superconductor-ferromagnet bilayer under external drive : the role of vortex-antivortex matter |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
119 |
Issue |
119 |
Pages |
093912 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using advanced Ginzburg-Landau simulations, we study the superconducting state of a thin superconducting film under a ferromagnetic layer, separated by an insulating oxide, in applied external magnetic field and electric current. The taken uniaxial ferromagnet is organized into a series of parallel domains with alternating polarization of out-of-plane magnetization, sufficiently strong to induce vortex-antivortex pairs in the underlying superconductor in absence of other magnetic field. We show the organization of such vortex-antivortex matter into rich configurations, some of which are not matching the periodicity of the ferromagnetic film. The variety of possible configurations is enhanced by applied homogeneous magnetic field, where additional vortices in the superconductor may lower the energy of the system by either annihilating the present antivortices under negative ferromagnetic domains or by lowering their own energy after positioning under positive ferromagnetic domains. As a consequence, both the vortex-antivortex reordering in increasing external field and the evolution of the energy of the system are highly nontrivial. Finally, we reveal the very interesting effects of applied dc electric current on the vortex-antivortex configurations, since resulting Lorentzian force has opposite direction for vortices and antivortices, while direction of the applied current with respect to ferromagnetic domains is of crucial importance for the interaction of the applied and the Meissner current, as well as the consequent vortex-antivortex dynamics-both of which are reflected in the anisotropic critical current of the system. (C) 2016 AIP Publishing LLC. |
| 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 |
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| Language |
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Wos |
000372351900018 |
Publication Date |
2016-03-07 |
| 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 |
0021-8979; 1089-7550 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.068 |
Times cited |
4 |
Open Access |
|
| Notes |
; This work was supported by the Brazilian agencies CNPq, PRONEX/FUNCAP, and CAPES, and the Research Foundation-Flanders (FWO). ; |
Approved |
Most recent IF: 2.068 |
| Call Number |
UA @ lucian @ c:irua:133200 |
Serial |
4255 |
| Permanent link to this record |
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| Author |
Chaves, A.; Moura, V.N.; Linard, F.J.A.; Covaci, L.; Milošević, M.V. |
| Title |
Tunable magnetic focusing using Andreev scattering in superconductor-graphene hybrid devices |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Journal Of Applied Physics |
Abbreviated Journal |
J Appl Phys |
| Volume |
128 |
Issue |
12 |
Pages |
124303 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
| Abstract |
We perform the wavepacket dynamics simulation of a graphene-based device where propagating electron trajectories are tamed by an applied magnetic field toward a normal/superconductor interface. The magnetic field controls the incidence angle of the incoming electronic wavepacket at the interface, which results in the tunable electron-hole ratio in the reflected wave function due to the angular dependence of the Andreev reflection. Here, mapped control of the quasiparticle trajectories by the external magnetic field not only defines an experimental probe for fundamental studies of the Andreev reflection in graphene but also lays the foundation for further development of magnetic focusing devices based on nanoengineered superconducting two-dimensional materials. |
| 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 |
000576393200002 |
Publication Date |
2020-09-28 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0021-8979; 1089-7550 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.2 |
Times cited |
1 |
Open Access |
Not_Open_Access |
| Notes |
; This work was supported by the Brazilian Council for Research (CNPq) through the PRONEX/FUNCAP and PQ programs and by the Research Foundation-Flanders (FWO). ; |
Approved |
Most recent IF: 3.2; 2020 IF: 2.068 |
| Call Number |
UA @ admin @ c:irua:172730 |
Serial |
6639 |
| Permanent link to this record |
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| Author |
da Costa, D.R.; Zarenia, M.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
| Title |
Analytical study of the energy levels in bilayer graphene quantum dots |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
| Volume |
78 |
Issue |
|
Pages |
392-400 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using the four-band continuum model we derive a general expression for the infinite-mass boundary condition in bilayer graphene. Applying this new boundary condition we analytically calculate the confined states and the corresponding wave functions in a bilayer graphene quantum dot in the absence and presence of a perpendicular magnetic field. Our results for the energy spectrum show an energy gap between the electron and hole states at small magnetic fields. Furthermore the electron (e) and hole (h) energy levels corresponding to the K and K' valleys exhibit the E-K(e(h)) (m) = E-K'(e(h)) (m) symmetry, where m is the angular momentum quantum number. (C) 2014 Elsevier Ltd. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Oxford |
Editor |
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| Language |
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Wos |
000341463900042 |
Publication Date |
2014-07-16 |
| 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 |
0008-6223; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.337 |
Times cited |
35 |
Open Access |
|
| Notes |
; This work was financially supported by CNPq, under contract NanoBioEstruturas 555183/2005-0, PRONEX/FUNCAP, CAPES Foundation under the process number BEX 7178/13-1, the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES program Euro-GRAPHENE (project CONGRAN), the Bilateral programme between CNPq and FWO-Vl, and the Brazilian Program Science Without Borders (CsF). We thank M. Ramezani Masir and M. Grujic for helpful comments and discussions. ; |
Approved |
Most recent IF: 6.337; 2014 IF: 6.196 |
| Call Number |
UA @ lucian @ c:irua:119280 |
Serial |
109 |
| Permanent link to this record |
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| Author |
Xavier, L.J.P.; Pereira, J.M.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
| Title |
Topological confinement in graphene bilayer quantum rings |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
| Volume |
96 |
Issue |
21 |
Pages |
212108,1-212108,3 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We find localized electron and hole states in a ring-shaped potential kink in biased bilayer graphene. Within the continuum description, we show that for sharp potential steps the Dirac equation describing carrier states close to the K (or K′) point of the first Brillouin zone can be solved analytically for a circular kink/antikink dot. The solutions exhibit interfacial states which exhibit AharonovBohm oscillations as functions of the height of the potential step and/or the radius of the ring. |
| 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 |
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| Language |
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Wos |
000278183200039 |
Publication Date |
2010-05-28 |
| 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 |
29 |
Open Access |
|
| Notes |
; This work was financially supported by CNPq, under Contract No. NanoBioEstruturas 555183/2005-0, FUNCAP, CAPES, the Bilateral program between Flanders and Brazil, the Belgian Science Policy (IAP) and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.411; 2010 IF: 3.841 |
| Call Number |
UA @ lucian @ c:irua:83373 |
Serial |
3675 |
| Permanent link to this record |
