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Records |
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Author |
Glazov, M.M.; Semina, M.A.; Badalyan, S.M.; Vignale, G. |
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Title |
Spin-current generation from Coulomb-Rashba interaction in semiconductor bilayers |
Type |
A1 Journal article |
| |
Year  |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
84 |
Issue |
3 |
Pages |
033305-033305,4 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Electrons in double-layer semiconductor heterostructures experience a special type of spin-orbit interaction that arises in each layer from the perpendicular component of the Coulomb electric field created by electron-density fluctuations in the other layer. We show that this interaction, acting in combination with the usual spin-orbit interaction, can generate a spin current in one layer when a charge current is driven in the other. This effect is distinct symmetrywise from the spin-Hall drag. The spin current is not, in general, perpendicular to the drive current. |
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Corporate Author |
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Place of Publication |
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Wos |
000293129200001 |
Publication Date |
2011-07-26 |
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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 |
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| |
Impact Factor |
3.836 |
Times cited |
5 |
Open Access |
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Notes |
; M.M.G. and M. A. S. are grateful to RFBR, EU projects Spinoptronics and POLAPHEN, and the “Dynasty” Foundation-ICFPM for financial support. S. M. B. acknowledges support from EU Grant No. PIIF-GA-2009-235394, the DFG SFB 689, and the Belgium Science Policy (IAP). G. V. acknowledges support from NSF Grant No. DMR-0705460. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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| |
Call Number |
UA @ lucian @ c:irua:91740 |
Serial |
3081 |
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| Permanent link to this record |
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Author |
Liu, Y.; Cheng, F.; Li, X.J.; Peeters, F.M.; Chang, K. |
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Title |
Tuning of anisotropy in two-electron quantum dots by spin-orbit interactions |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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| |
Volume |
99 |
Issue |
3 |
Pages |
032102,1-032102,3 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We investigate the influence of the spin-orbit interactions (SOIs) on the electron distribution and the optical absorption of a two-electron quantum dot. It is shown that the interplay between the SOIs makes the two-electron quantum dot behave like two laterally coupled quantum dots and the anisotropic distribution can be rotated from [110] to [11®0] by reversing the direction of the perpendicular electric field and detect it through the optical absorption spectrum. |
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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 |
000293679000026 |
Publication Date |
2011-07-18 |
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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 |
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Impact Factor |
3.411 |
Times cited |
8 |
Open Access |
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Notes |
; This work was supported by NSFC Grants No. 16760525405, 10874175 and 11004017 and the Belgian Science Policy 168(IAP). ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
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| |
Call Number |
UA @ lucian @ c:irua:92473 |
Serial |
3749 |
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Author |
Masir, M.R.; Vasilopoulos, P.; Peeters, F.M. |
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Title |
Graphene in inhomogeneous magnetic fields : bound, quasi-bound and scattering states |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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| |
Volume |
23 |
Issue |
31 |
Pages |
315301,1-315301,14 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The electron states in graphene-based magnetic dot and magnetic ring structures and combinations of both are investigated. The corresponding spectra are studied as a function of the radii, the strengths of the inhomogeneous magnetic field and of a uniform background field, the strength of an electrostatic barrier and the angular momentum quantum number. In the absence of an external magnetic field we have only long-lived quasi-bound and scattering states and we assess their influence on the density of states. In addition, we consider elastic electron scattering by a magnetic dot, whose average B vanishes, and show that the Hall and longitudinal resistivities, as a function of the Fermi energy, exhibit a pronounced oscillatory structure due to the presence of quasi-bound states. Depending on the dot parameters this oscillatory structure differs substantially for energies below and above the first Landau level. |
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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 |
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Language |
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Wos |
000293008900002 |
Publication Date |
2011-07-16 |
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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 |
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| |
Impact Factor |
2.649 |
Times cited |
38 |
Open Access |
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Notes |
; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE, the Canadian NSERC grant no. OGP0121756 and the Belgian Science Policy (IAP). We acknowledge discussions and correspondence with Professor A Matulis. ; |
Approved |
Most recent IF: 2.649; 2011 IF: 2.546 |
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Call Number |
UA @ lucian @ c:irua:91176 |
Serial |
1372 |
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Author |
Zarenia, M.; Pereira, J.M.; Peeters, F.M.; Farias, G. de A. |
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Title |
Topological confinement in an antisymmetric potential in bilayer graphene in the presence of a magnetic field |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Nanoscale research letters |
Abbreviated Journal |
Nanoscale Res Lett |
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Volume |
6 |
Issue |
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Pages |
452,1-452,10 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We investigate the effect of an external magnetic field on the carrier states that are localized at a potential kink and a kink-antikink in bilayer graphene. These chiral states are localized at the interface between two potential regions with opposite signs. |
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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 |
000293299800001 |
Publication Date |
2011-07-14 |
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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 |
1556-276X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.833 |
Times cited |
4 |
Open Access |
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Notes |
; This work was supported by the Brazilian agency CNPq (Pronex), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the bilateral projects between Flanders and Brazil and FWO-CNPq. ; |
Approved |
Most recent IF: 2.833; 2011 IF: NA |
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Call Number |
UA @ lucian @ c:irua:91745 |
Serial |
3674 |
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Author |
Nowak, M.P.; Szafran, B.; Peeters, F.M.; Partoens, B.; Pasek, W.J. |
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Title |
Tuning of the spin-orbit interaction in a quantum dot by an in-plane magnetic field |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
24 |
Pages |
245324-245324,12 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using an exact-diagonalization approach we show that one- and two-electron InAs quantum dots exhibit an avoided crossing in the energy spectra that is induced by the spin-orbit coupling in the presence of an in-plane external magnetic field. The width of the avoided crossings depends strongly on the orientation of the magnetic field, which reveals the intrinsic anisotropy of the spin-orbit-coupling interactions. We find that for specific orientations of the magnetic field avoided crossings vanish. A value of this orientation can be used to extract the ratio of the strength of Rashba and Dresselhaus interactions. The spin-orbit anisotropy effects for various geometries and orientations of the confinement potential are discussed. Our analysis explains the physics behind the recent measurements performed on a gated self-assembled quantum dot [ S. Takahashi et al. Phys. Rev. Lett. 104 246801 (2010)]. |
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Place of Publication |
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Editor |
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Language |
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Wos |
000292254000005 |
Publication Date |
2011-06-30 |
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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 |
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Impact Factor |
3.836 |
Times cited |
27 |
Open Access |
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Notes |
; The authors thank S. Takahashi for helpful discussions. This work was supported by the “Krakow Interdisciplinary PhD Project in Nanoscience and Advanced Nanostructures” operated within the Foundation for Polish Science MPD Programme co-financed by the EU European Regional Development Fund, the Project No. N N202103938 supported by the Ministry of Science an Higher Education (MNiSW) for 2010-2013, and the Belgian Science Policy (IAP). W. J. P. has been partially supported by the EU Human Capital Operation Program, Polish Project No. POKL.04.0101-00-434/08-00. Calculations were performed in ACK-CYFRONET-AGH on the RackServer Zeus. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:90923 |
Serial |
3755 |
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Author |
Neek-Amal, M.; Peeters, F.M. |
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Title |
Lattice thermal properties of graphane : thermal contraction, roughness, and heat capacity |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
83 |
Issue |
23 |
Pages |
235437-235437,6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using atomistic simulations, we determine the roughness and the thermal properties of a suspended graphane sheet. As compared to graphene, we found that (i) hydrogenated graphene has a larger thermal contraction, (ii) the roughness exponent at room temperature is smaller, i.e., ≃ 1.0 versus ≃ 1.2 for graphene, (iii) the wavelengths of the induced ripples in graphane cover a wide range corresponding to length scales in the range 30125 Å at room temperature, and (iv) the heat capacity of graphane is estimated to be 29.32±0.23 J/mol K, which is 14.8% larger than that for graphene, i.e., 24.98±0.14 J/mol K. Above 1500 K, we found that graphane buckles when its edges are supported in the x-y plane. |
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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 |
000292253400011 |
Publication Date |
2011-06-30 |
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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 |
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Impact Factor |
3.836 |
Times cited |
42 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgium Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:90921 |
Serial |
1803 |
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Author |
Chaves, A.; Komendová, L.; Milošević, M.V.; Andrade, J.S.; Farias, G.A.; Peeters, F.M. |
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Title |
Conditions for nonmonotonic vortex interaction in two-band superconductors |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
83 |
Issue |
21 |
Pages |
214523-214523,6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We describe a semianalytic approach to the two-band Ginzburg-Landau theory, which predicts the behavior of vortices in two-band superconductors. We show that the character of the short-range vortex-vortex interaction is determined by the sign of the normal domain-superconductor interface energy, in analogy with the conventional differentiation between type I and type II superconductors. However, we also show that the long-range interaction is determined by a modified Ginzburg-Landau parameter κ*, different from the standard κ of a bulk superconductor. This opens the possibility for nonmonotonic vortex-vortex interaction, which is temperature dependent, and can be further tuned by alterations of the material on the microscopic scale. |
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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 |
000292252300009 |
Publication Date |
2011-06-30 |
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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 |
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Impact Factor |
3.836 |
Times cited |
46 |
Open Access |
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Notes |
; Discussions with A. Moreira, A. Shanenko, R. Prozorov, and A. Golubov are gratefully acknowledged. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the bilateral project FWO-CNPq, CAPES, and PRONEX/CNPq/FUNCAP. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:90922 |
Serial |
477 |
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Author |
Vodolazov, D.Y.; Peeters, F.M. |
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Title |
Heating of quasiparticles driven by oscillations of the order parameter in short superconducting microbridges |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
83 |
Issue |
22 |
Pages |
224523-224523,6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We predict heating of quasiparticles driven by order parameter oscillations in the resistive state of short superconducting microbridges. The finite relaxation time of the magnitude of the order parameter |Δ| and the dependence of the spectral functions both on |Δ| and the supervelocity Q are the origin of this effect. Our results are opposite to those of Aslamazov and Larkin [ Zh. Eks. Teor. Fiz. 70 1340 (1976)] and Schmid et al. [ Phys. Rev. B 21 5076 (1980)] where cooling of quasiparticles was found. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000292218200010 |
Publication Date |
2011-06-29 |
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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 |
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| |
Impact Factor |
3.836 |
Times cited |
4 |
Open Access |
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Notes |
; This work was supported by the Russian Foundation for Basic Research, Russian Agency of Education under the Federal Target Programme “Scientific and educational personnel of innovative Russia in 2009-2013,” Flemish Science Foundation (FWO-Vl), and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:90924 |
Serial |
1415 |
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Author |
Vandenberghe, W.; Sorée, B.; Magnus, W.; Fischetti, M.V. |
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Title |
Generalized phonon-assisted Zener tunneling in indirect semiconductors with non-uniform electric fields : a rigorous approach |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
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Volume |
109 |
Issue |
12 |
Pages |
124503-124503,12 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A general framework to calculate the Zener current in an indirect semiconductor with an externally applied potential is provided. Assuming a parabolic valence and conduction band dispersion, the semiconductor is in equilibrium in the presence of the external field as long as the electron-phonon interaction is absent. The linear response to the electron-phonon interaction results in a non-equilibrium system. The Zener tunneling current is calculated from the number of electrons making the transition from valence to conduction band per unit time. A convenient expression based on the single particle spectral functions is provided, enabling the evaluation of the Zener tunneling current under any three-dimensional potential profile. For a one-dimensional potential profile an analytical expression is obtained for the current in a bulk semiconductor, a semiconductor under uniform field, and a semiconductor under a non-uniform field using the WKB (Wentzel-Kramers-Brillouin) approximation. The obtained results agree with the Kane result in the low field limit. A numerical example for abrupt p-n diodes with different doping concentrations is given, from which it can be seen that the uniform field model is a better approximation than the WKB model, but a direct numerical treatment is required for low bias conditions. |
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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 |
000292331200134 |
Publication Date |
2011-06-21 |
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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; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.068 |
Times cited |
41 |
Open Access |
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Notes |
; William 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: 2.068; 2011 IF: 2.168 |
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Call Number |
UA @ lucian @ c:irua:90808 |
Serial |
1325 |
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Author |
Engbarth, M.A.; Bending, S.J.; Milošević, M.V. |
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Title |
Geometry-driven vortex states in type-I superconducting Pb nanowires |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
83 |
Issue |
22 |
Pages |
224504-224504,7 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Hall probe magnetometry has been used to investigate the magnetization of individual cylindrically shaped Pb nanowires grown by electrocrystallization on a highly oriented pyrolytic graphite electrode. These measurements have been interpreted by comparison with three-dimensional Ginzburg-Landau (GL) calculations for nanowires with our sample parameters. We find that the measured superheating field and the critical field for surface superconductivity are strongly influenced by the temperature-dependent coherence length, ξ(T) and penetration depth λ(T) and their relationship to the nanowire diameter. As the temperature is increased toward Tc this drives a change in the superconductor-normal transition from first order irreversible to first order reversible and finally second order reversible. We find that the geometrical flux confinement in our type-I nanowires leads to the formation of a one-dimensional row of single-quantum vortices. While GL calculations show a quite uniform distribution of vortices in thin nanowires, clear vortex bunching is found as the diameter increases, suggesting a transition to a more classical type-I behavior. Subtle changes in minor magnetization loops also indicate that slightly different flux configurations can form with the same vorticity, which depend on the sample history. |
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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 |
000291888300012 |
Publication Date |
2011-06-21 |
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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 |
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| |
Impact Factor |
3.836 |
Times cited |
19 |
Open Access |
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Notes |
; We acknowledge valuable conversations with F. V. Kusmartsev and W. M. Wu at Loughborough University, UK. This work was supported by the EPSRC-UK under Grant No. EP/E039944/1, and the Flemish Science Foundation (FWO). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:90927 |
Serial |
1331 |
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Author |
Rakhimov, K.Y.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
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Title |
Wavepacket scattering of Dirac and Schrödinger particles on potential and magnetic barriers |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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| |
Volume |
23 |
Issue |
27 |
Pages |
275801,1-275801,16 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We investigate the dynamics of a charged particle moving in a graphene layer and in a two-dimensional electron gas, where it obeys the Dirac and the Schrödinger equations, respectively. The charge carriers are described as Gaussian wavepackets. The dynamics of the wavepackets is studied numerically by solving both quantum-mechanical and relativistic equations of motion. The scattering of such wavepackets by step-like magnetic and potential barriers is analysed for different values of wavepacket energy and width. We find: (1) that the average position of the wavepacket does not coincide with the classical trajectory, and (2) that, for slanted incidence, the path of the centre of mass of the wavepacket does not have to penetrate the barrier during the scattering process. Trembling motion of the charged particle in graphene is observed in the absence of an external magnetic field and can be enhanced by a substrate-induced mass term. |
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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 |
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Language |
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Wos |
000291993600009 |
Publication Date |
2011-06-18 |
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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 |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.649 |
Times cited |
32 |
Open Access |
|
|
| |
Notes |
; Discussions with A Matulis are gratefully acknowledged. KR is beneficiary of a mobility grant from the Belgian Federal Science Policy Office, co-funded by the European Commission and was supported in part by a grant of the Third World Academy of Sciences (ref. 09-188 RG/PHYS/AS-I). In addition, this work was financially supported by CNPq, under contract NanoBioEstruturas 555183/2005-0, PRONEX/FUNCAP, CAPES, the Bilateral programme between Flanders and Brazil, the joint project CNPq-FWO, the Belgian Science Policy (IAP) and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 2.649; 2011 IF: 2.546 |
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| |
Call Number |
UA @ lucian @ c:irua:90880 |
Serial |
3908 |
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| Permanent link to this record |
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| |
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Author |
Tognalii, N.G.; Cortés, E.; Hernández-Nieves, A.D.; Carro, P.; Usaj, G.; Balseiro, C.A.; Vela, M.E.; Salvarezza, R.C.; Fainstein, A. |
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| |
Title |
From single to multiple Ag-layer modification of Au nanocavity substrates : a tunable probe of the chemical surface-enhanced Raman scattering mechanism |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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| |
Volume |
5 |
Issue |
7 |
Pages |
5433-5443 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We present experimental and computational results that enlighten the mechanisms underlying the chemical contribution to surface-enhanced Raman scattering (SERS). Gold void metallic arrays electrochemically covered either by a Ag monolayer or 10100 Ag layers were modified with a self-assembled monolayer of 4-mercaptopyridine as a molecular Raman probe displaying a rich and unexpected Raman response. A resonant increase of the Raman intensity in the red part of the spectrum is observed that cannot be related to plasmon excitations of the cavity-array. Notably, we find an additional 1020 time increase of the SERS amplification upon deposition of a single Ag layer on the Au substrate, which is, however, almost quenched upon deposition of 10 atomic layers. Further deposition of 100 atomic Ag layers results in a new increase of the SERS signal, consistent with the improved plasmonic efficiency of Ag bulk-like structures. The SERS response as a function of the Ag layer thickness is analyzed in terms of ab initio calculations and a microscopic model for the SERS chemical mechanism based on a resonant charge transfer process between the molecular HOMO state and the Fermi level in the metal surface. We find that a rearrangement of the electronic charge density related to the presence of the Ag monolayer in the Au/Ag/molecule complex causes an increase in the distance between the HOMO center of charge and the metallic image plane that is responsible for the variation of Raman enhancement between the studied substrates. Our results provide a general platform for studying the chemical contribution to SERS, and for enhancing the Raman efficiency of tailored Au-SERS templates through electrochemical modification with Ag films. |
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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 |
000293035200019 |
Publication Date |
2011-06-15 |
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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 |
|
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| |
ISSN |
1936-0851;1936-086X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
13.942 |
Times cited |
26 |
Open Access |
|
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| |
Notes |
; We acknowledge financial support from ANPCyT (Argentina, PICT08-1617, PICT08-2236, PICT06-621, PICT-CNPQ-08-0019, PAE 22711, PICT06-01061, PICT06-483) and Project CTQ2008-06017/BQU, Spain. N.G.T, E.C., A.D.H.N., R.C.S, G.U., C.A.B., and A.F. are also at CONICET. M.E.V. is a member of the research career of CIC BsAs. R.C.S., C.A.B., and A.F. are Guggenheim Foundation Fellows. We would like to thank Dr. M. H. Fonticelli for fruitful discussions on the electrochemical measurements and Dr. H. Pastoriza for the help with the SEM measurements. ; |
Approved |
Most recent IF: 13.942; 2011 IF: 11.421 |
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| |
Call Number |
UA @ lucian @ c:irua:91775 |
Serial |
1285 |
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| 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. |
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| |
Title |
Metallic nanograins : spatially nonuniform pairing induced by quantum confinement |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
21 |
Pages |
214509-214509,12 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
It is well known that the formation of discrete electron levels strongly influences the pairing in metallic nanograins. Here, we focus on another effect of quantum confinement in superconducting grains that was not studied previously, i.e., spatially nonuniform pairing. This effect is very significant when single-electron levels form bunches and/or a kind of shell structure. We find that, in highly symmetric grains, the order parameter can exhibit variations with position by an order of magnitude. Nonuniform pairing is closely related to a quantum-confinement-induced modification of the pairing-interaction matrix elements and size-dependent pinning of the chemical potential to groups of degenerate or nearly degenerate levels. For illustrative purposes, we consider spherical metallic nanograins and also rectangular shapes. We show that the relevant matrix elements are, as a rule, enhanced in the presence of quantum confinement, which favors spatial variations of the order parameter, compensating the corresponding energy cost. The size-dependent pinning of the chemical potential further increases the spatial variation of the pair condensate. The role of nonuniform pairing is smaller in less symmetric confining geometries and/or in the presence of disorder. However, it always remains of importance when the energy spacing between discrete electron levels δ is approaching the scale of the bulk gap ΔB, i.e., δ>0.10.2 ΔB. |
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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 |
000291310000006 |
Publication Date |
2011-06-06 |
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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 |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
23 |
Open Access |
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| |
Notes |
; This work was supported by the Alexander von Humboldt Foundation, the Flemish Science Foundation (FWO-VI), and the Belgian Science Policy (IAP). M. D. C. acknowledges support of the European Community under a Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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| |
Call Number |
UA @ lucian @ c:irua:90081 |
Serial |
2010 |
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| Permanent link to this record |
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Author |
Nasirpouri, F.; Engbarth, M.A.; Bending, S.J.; Peter, L.M.; Knittel, A.; Fangohr, H.; Milošević, M.V. |
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Title |
Three-dimensional ferromagnetic architectures with multiple metastable states |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
|
| |
Volume |
98 |
Issue |
22 |
Pages |
222506,1-222506,3 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We demonstrate controllable dual-bath electrodeposition of nickel on architecture-tunable three-dimensional (3D) silver microcrystals. Magnetic hysteresis loops of individual highly faceted Ag-Ni core-shell elements reveal magnetization reversal that comprises multiple sharp steps corresponding to different stable magnetic states. Finite-element micromagnetic simulations on smaller systems show several jumps during magnetization reversal which correspond to transitions between different magnetic vortex states. Structures of this type could be realizations of an advanced magnetic data storage architecture whereby each element represents one multibit, storing a combination of several conventional bits depending on the overall number of possible magnetic states associated with the 3D core-shell shape. |
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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 |
000291405700044 |
Publication Date |
2011-06-03 |
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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 |
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| |
Impact Factor |
3.411 |
Times cited |
8 |
Open Access |
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| |
Notes |
; This work was supported by EPSRC in the U.K. under Grant Nos. EP/E039944/1 and EP/E040063/1, DYNAMAG project (EU FP7/2007-2013 Grant No. 233552), and FWO-Vlaanderen. ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
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Call Number |
UA @ lucian @ c:irua:90008 |
Serial |
3652 |
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| Permanent link to this record |
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Author |
Dixit, H.; Tandon, N.; Cottenier, S.; Saniz, R.; Lamoen, D.; Partoens, B.; van Speybroeck, V.; Waroquier, M. |
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Title |
Electronic structure and band gap of zinc spinel oxides beyond LDA : ZnAl2O4, ZnGa2O4 and ZnIn2O4 |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
New journal of physics |
Abbreviated Journal |
New J Phys |
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| |
Volume |
13 |
Issue |
6 |
Pages |
063002-063002,11 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
We examine the electronic structure of the family of ternary zinc spinel oxides ZnX2O4 (X=Al, Ga and In). The band gap of ZnAl2O4 calculated using density functional theory (DFT) is 4.25 eV and is overestimated compared with the experimental value of 3.83.9 eV. The DFT band gap of ZnGa2O4 is 2.82 eV and is underestimated compared with the experimental value of 4.45.0 eV. Since DFT typically underestimates the band gap in the oxide system, the experimental measurements for ZnAl2O4 probably require a correction. We use two first-principles techniques capable of describing accurately the excited states of semiconductors, namely the GW approximation and the modified BeckeJohnson (MBJ) potential approximation, to calculate the band gap of ZnX2O4. The GW and MBJ band gaps are in good agreement with each other. In the case of ZnAl2O4, the predicted band gap values are >6 eV, i.e. ~2 eV larger than the only reported experimental value. We expect future experimental work to confirm our results. Our calculations of the electron effective masses and the second band gap indicate that these compounds are very good candidates to act as transparent conducting host materials. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000292137500002 |
Publication Date |
2011-06-03 |
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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 |
1367-2630; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.786 |
Times cited |
98 |
Open Access |
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Notes |
Iwt; Fwo; Bof-Noi |
Approved |
Most recent IF: 3.786; 2011 IF: 4.177 |
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Call Number |
UA @ lucian @ c:irua:89555 |
Serial |
1008 |
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| Permanent link to this record |
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Author |
Li, Z.; Covaci, L.; Berciu, M.; Baillie, D.; Marsiglio, F. |
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Title |
Impact of spin-orbit coupling on the Holstein polaron |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
19 |
Pages |
195104-195104,9 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We utilize an exact variational numerical procedure to calculate the ground state properties of a polaron in the presence of a Rashba-like spin-orbit interaction. Our results corroborate previous work performed with the momentum average approximation and with weak-coupling perturbation theory. We find that spin-orbit coupling increases the effective mass in the regime with weak electron-phonon coupling, and decreases the effective mass in the regimes of intermediate and strong electron-phonon coupling. Analytical strong-coupling perturbation theory results confirm our numerical results in the small-polaron regime. A large amount of spin-orbit coupling can lead to a significant lowering of the polaron effective mass. |
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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 |
000290162500001 |
Publication Date |
2011-05-03 |
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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 |
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| |
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
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Notes |
; This work was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC), by ICORE (Alberta), by Alberta Ingenuity, by the Flemish Science Foundation (FWO-Vl), and by the Canadian Institute for Advanced Research (CIfAR). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:89718 |
Serial |
1561 |
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| Permanent link to this record |
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Author |
Wu, Z.; Zhai, F.; Peeters, F.M.; Xu, H.Q.; Chang, K. |
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Title |
Valley-dependent brewster angles and Goos-Hänchen effect in strained graphene |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review letters |
Abbreviated Journal |
Phys Rev Lett |
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| |
Volume |
106 |
Issue |
17 |
Pages |
176802,1-176802,4 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We demonstrate theoretically how local strains in graphene can be tailored to generate a valley-polarized current. By suitable engineering of local strain profiles, we find that electrons in opposite valleys (K or K′) show different Brewster-like angles and Goos-Hänchen shifts, exhibiting a close analogy with light propagating behavior. In a strain-induced waveguide, electrons in K and K′ valleys have different group velocities, which can be used to construct a valley filter in graphene without the need for any external fields. |
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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 |
000290100300016 |
Publication Date |
2011-04-29 |
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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 |
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| |
Impact Factor |
8.462 |
Times cited |
235 |
Open Access |
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Notes |
; This work was supported by the NSF of China and the MOST, the Swedish International Development Cooperation Agency (SIDA), and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 8.462; 2011 IF: 7.370 |
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Call Number |
UA @ lucian @ c:irua:89715 |
Serial |
3832 |
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Author |
Apolinario, S.W.S.; Peeters, F.M. |
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Title |
Binary dusty plasma Coulomb balls |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics |
Abbreviated Journal |
Phys Rev E |
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| |
Volume |
83 |
Issue |
4 |
Pages |
041136,1-041136,8 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We investigated the mixing and segregation of a system consisting of two different species of particles, having different charges, interacting through a pure Coulomb potential, and confined in a three-dimensional parabolic trap. The structure of the cluster and its normal mode spectrum are analyzed as a function of the relative charge and the relative number of different types of particles. We found that (a) the system can be in a mixed or segregated state depending on the relative charge ratio parameter and (b) the segregation process is mediated by a first or second order structural phase transition which strongly influences the magic cluster properties of the system. |
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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 |
000290154900004 |
Publication Date |
2011-04-29 |
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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 |
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| |
Impact Factor |
2.366 |
Times cited |
10 |
Open Access |
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Notes |
; This work was supported by FACEPE (Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco) and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 2.366; 2011 IF: 2.255 |
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| |
Call Number |
UA @ lucian @ c:irua:89716 |
Serial |
236 |
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Author |
Lobato, I.; Partoens, B. |
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Title |
Multiple Dirac particles in AA-stacked graphite and multilayers of graphene |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
16 |
Pages |
165429-165429,9 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
Using the tight-binding formalism we show that in the recently experimentally realized AA-stacked graphite in essence two types of massless relativistic Dirac particles are present with a different effective speed of light. We also investigate how the electronic structure evolves from a single graphene sheet into AA-stacked graphite. It is shown that in contrast to AB-stacked graphene layers, the spectrum of AA-stacked graphene layers can be considered as a superposition of single-layer spectra and only particles with a linear spectrum at the Fermi energy around the K point are present. From the evolution of the band overlap we show that 6 multilayers of AA-stacked graphene already behave as AA-stacked graphite. The evolution of the effective speeds of light of the Dirac particles to their bulk values shows exactly the same behavior. The tight-binding parameters we use to describe AA-stacked graphite and multilayers of graphene are obtained by ab initio calculations. |
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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 |
000290113900005 |
Publication Date |
2011-04-21 |
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| |
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 |
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| |
Impact Factor |
3.836 |
Times cited |
68 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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| |
Call Number |
UA @ lucian @ c:irua:89717 |
Serial |
2225 |
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| Permanent link to this record |
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Author |
Wu, Z.; Peeters, F.M.; Chang, K. |
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Title |
Spin and momentum filtering of electrons on the surface of a topological insulator |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
|
| |
Volume |
98 |
Issue |
16 |
Pages |
162101,1-162101,3 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We investigate theoretically the transport properties of Dirac fermions on the surface of a three-dimensional topological insulator. Dirac electrons can be totally reflected in front of a magnetic/electric p-n junction. For a p-n-p structure, multiple total internal reflections at the interfaces result in the bound states in the channel, which behaves like an electronic waveguide. This p-n-p like structure exhibits spin and momentum filtering features and could be used as a spin and/or charge diode. |
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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 |
000289842700032 |
Publication Date |
2011-04-18 |
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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 |
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| |
Impact Factor |
3.411 |
Times cited |
33 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
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| |
Call Number |
UA @ lucian @ c:irua:89971 |
Serial |
3076 |
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| Permanent link to this record |
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Author |
Ding, F.; Li, B.; Akopian, N.; Perinetti, U.; Chen, Y.H.; Peeters, F.M.; Rastelli, A.; Zwiller, V.; Schmidt, O.G. |
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| |
Title |
Single neutral excitons confined in AsBr3 in situ etched InGaAs quantum rings |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Journal of nanoelectronics and optoelectronics |
Abbreviated Journal |
J Nanoelectron Optoe |
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| |
Volume |
6 |
Issue |
1 |
Pages |
51-57 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
We observe the evolution of single self-assembled semiconductor quantum dots into quantum rings during AsBr3 in situ etching. The direct three-dimensional imaging of In(Ga)As nanostructures embedded in GaAs matrix is demonstrated by selective wet chemical etching combined with atomic force microscopy. Single neutral excitons confined in these quantum rings are studied by magneto-photoluminescence. Oscillations in the exciton radiative recombination energy and in the emission intensity are observed under an applied magnetic field. Further, we demonstrate that the period of the oscillations can be tuned by a gate potential that modifies the exciton confinement. The experimental results, combined with calculations, indicate that the exciton Aharonov-Bohm effect may account for the observed effects. |
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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 |
000290692200005 |
Publication Date |
2011-04-18 |
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| |
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 |
1555-130X;1555-1318; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
0.497 |
Times cited |
3 |
Open Access |
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| |
Notes |
; We acknowledge L. P. Kouwenhoven and Z. G. Wang for support, C. C. Bof Bufon, C. Deneke, V. Fomin, A. Govorov, S. Kiravittaya, and Wen-Hao Chang for their help and discussions. We are grateful for the financial support of NWO (VIDI), the CAS-MPG programm, the DFG (FOR730), BMBF (No. 01BM459), NSFC China (60625402), and Flemish Science Foundation (FWO-V1). ; |
Approved |
Most recent IF: 0.497; 2011 IF: 0.556 |
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| |
Call Number |
UA @ lucian @ c:irua:90187 |
Serial |
3025 |
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| Permanent link to this record |
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| |
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Author |
Dzhurakhalov, A.A.; Peeters, F.M. |
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| |
Title |
Structure and energetics of hydrogen chemisorbed on a single graphene layer to produce graphane |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Carbon |
Abbreviated Journal |
Carbon |
|
| |
Volume |
49 |
Issue |
10 |
Pages |
3258-3266 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Integrated Molecular Plant Physiology Research (IMPRES) |
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| |
Abstract |
Chemisorption of hydrogen on graphene is studied using atomistic simulations with the second generation of reactive empirical bond order Brenner inter-atomic potential. The lowest energy adsorption sites and the most important metastable sites are determined. The H concentration is varied from a single H atom, to clusters of H atoms up to full coverage. We found that when two or more H atoms are present, the most stable configurations of H chemisorption on a single graphene layer are ortho hydrogen pairs adsorbed on one side or on both sides of the graphene sheet. The latter has the highest hydrogen binding energy. The next stable configuration is the orthopara pair combination, and then para hydrogen pairs. The structural changes of graphene caused by chemisorbed hydrogen are discussed and are compared with existing experimental data and other theoretical calculations. The obtained results will be useful for nanoengineering of graphene by hydrogenation and for hydrogen storage. |
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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 |
000291959300014 |
Publication Date |
2011-04-15 |
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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 |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.337 |
Times cited |
46 |
Open Access |
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| |
Notes |
; A.D. thanks M.W. Zhao for a useful correspondence. This work was supported by the Belgian Science Policy (IAP) and the Flemish Science Foundation (FWO-VI). ; |
Approved |
Most recent IF: 6.337; 2011 IF: 5.378 |
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| |
Call Number |
UA @ lucian @ c:irua:90877 |
Serial |
3275 |
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| Permanent link to this record |
| |
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| |
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Author |
Vandenberghe, W.G.; Sorée, B.; Magnus, W.; Groeseneken, G.; Fischetti, M.V. |
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| |
Title |
Impact of field-induced quantum confinement in tunneling field-effect devices |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
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| |
Volume |
98 |
Issue |
14 |
Pages |
143503,1-143503,3 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Being the working principle of a tunnel field-effect transistor, band-to-band tunneling is given a rigorous quantum mechanical treatment to incorporate confinement effects, multiple electron and hole valleys, and interactions with phonons. The model reveals that the strong band bending near the gate dielectric, required to create short tunnel paths, results in quantization of the energy bands. Comparison with semiclassical models reveals a big shift in the onset of tunneling. The effective mass difference of the distinct valleys is found to reduce the subthreshold swing steepness. |
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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 |
000289297800074 |
Publication Date |
2011-04-06 |
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| |
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 |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.411 |
Times cited |
76 |
Open Access |
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| |
Notes |
; The authors acknowledge Anne Verhulst for useful discussions. William 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). This work was supported by IMEC's Industrial Affiliation Program. ; |
Approved |
Most recent IF: 3.411; 2011 IF: 3.844 |
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| |
Call Number |
UA @ lucian @ c:irua:89297 |
Serial |
1559 |
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| Permanent link to this record |
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| |
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Author |
Liu, C.-Y.; Berdiyorov, G.R.; Milošević, M.V. |
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| |
Title |
Vortex states in layered mesoscopic superconductors |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
10 |
Pages |
104524-104524,10 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Within the Ginzburg-Landau theory, we study the vortex structures in three-dimensional anisotropic mesoscopic superconductors in the presence of a uniform magnetic field. Anisotropy is included through varied Tc in different layers of the sample and leads to distinct differences in the vortex states and their free energy. Several unconventional states are found, some comprising vortex clusters or exhibiting asymmetry. In a tilted magnetic field, we found second-order transitions between different vortex states, although vortex entry is generally a first-order transition in mesoscopic samples. In multilayered samples the kinked vortex strings are formed owing to the competing interactions of vortices with Meissner currents and the weak-link boundaries. The length and deformation of vortex fragments are determined solely by the inclination and strength of applied magnetic field, and this lock-in does not depend on the degree of anisotropy between the superconducting layers. |
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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 |
000288998200003 |
Publication Date |
2011-03-31 |
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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 |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
22 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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| |
Call Number |
UA @ lucian @ c:irua:89375 |
Serial |
3888 |
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| Permanent link to this record |
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Author |
Matulis, A.; Masir, M.R.; Peeters, F.M. |
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| |
Title |
Application of optical beams to electrons in graphene |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
11 |
Pages |
115458-115458,7 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The technique of beam optics is applied to the description of the wave function of Dirac electrons. This approach is illustrated by considering electron transmission through simple nonhomogeneous structures, such as flat and bent p-n junctions and superlattices. We found that a convex p-n junction compresses the beam waist, while a concave interface widens it without loosing its focusing properties. At a flat p-n junction the waist of the transmitted Gaussian beam can be narrowed or widened, depending on the angle of incidence. A general condition is derived for the occurrence of beam collimation in a superlattice which is less stringent than previous discussed. |
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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 |
000288896400013 |
Publication Date |
2011-03-29 |
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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 |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
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| |
Notes |
; This research was supported by the Flemish Science Foundation (Grant No. FWO-Vl), by the Belgian Science policy (IAP), and (in part) by the Lithuanian Science Council under project No. MIP-79/2010. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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| |
Call Number |
UA @ lucian @ c:irua:89377 |
Serial |
142 |
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| Permanent link to this record |
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Author |
Li, B.; Peeters, F.M. |
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Title |
Tunable optical Aharonov-Bohm effect in a semiconductor quantum ring |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
11 |
Pages |
115448-115448,13 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
By applying an electric field perpendicular to a semiconductor quantum ring we show that it is possible to modify the single particle wave function between quantum dot (QD)-like and ring-like. The constraints on the geometrical parameters of the quantum ring to realize such a transition are derived. With such a perpendicular electric field we are able to tune the Aharanov-Bohm (AB) effect for both the single particle and for excitons. The tunability is in both the strength of the AB effect as well as in its periodicity. We also investigate the strain induce potential inside the self-assembled quantum ring and the effect of the strain on the AB effect. |
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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 |
000288855200012 |
Publication Date |
2011-03-28 |
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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 |
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| |
Impact Factor |
3.836 |
Times cited |
25 |
Open Access |
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| |
Notes |
; This work was supported by the EU-NoE: SANDiE, the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles, Belgium State, Belgium Science Policy, and IMEC, vzw collaborative project. We are grateful to Prof. M. Tadic and Dr. Fei Ding for stimulating discussions. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:89376 |
Serial |
3744 |
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| Permanent link to this record |
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Author |
Michel, K.H.; Verberck, B. |
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Title |
Phonon dispersions and piezoelectricity in bulk and multilayers of hexagonal boron nitride |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
11 |
Pages |
115328-115328,14 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A unified theory of phonon dispersions and piezoelectricity in bulk and multilayers of hexagonal boron nitride (h-BN) is derived. The dynamical matrix is calculated on the basis of an empirical force constant model of intralayer valence and interlayer van der Waals interactions. Coulomb interactions are calculated by Ewalds method, adapted for the three-dimensional (3D) and the multilayer case. The deformation of the ionic charge distribution with long-wave lattice displacements is taken into account. Special attention is devoted to the nonanalytic long-range Coulomb contribution to the dynamical matrix which is different for the 3D crystal and the multilayer case. Consequently there is a splitting of the transverse optical (TO) and longitudinal optical (LO) phonon branches of E1u symmetry and a discontinuity of the A2u branch at the Γ point in 3D h-BN. No such splitting and discontinuity at Γ are present in multilayer crystals with a finite number N of layers. There a diverging bundle of N overbending optical phonon branches emerges from Γ. Borns long-wave theory is applied and extended for the study of piezoelectricity in layered crystals. While 3D h-BN and h-BN multilayers with an even number of layers (symmetry D6h) are not piezoelectric, multilayers with an uneven number of Nu layers (symmetry D3h) are piezoelectric; the piezoelectric coefficient e1,11 is inversely proportional to Nu. |
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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 |
000288783700005 |
Publication Date |
2011-03-24 |
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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 |
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| |
Impact Factor |
3.836 |
Times cited |
82 |
Open Access |
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Notes |
; Discussions with G. Heger, B. Partoens, and F. M. Peeters are gratefully acknowledged. This work has been supported by the Flemish Science Foundation (FWO-V1) and the Bijzonder Onderzoeksfonds, Universiteit Antwerpen (BOF-UA). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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| |
Call Number |
UA @ lucian @ c:irua:89602 |
Serial |
2603 |
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| Permanent link to this record |
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Author |
Verberck, B.; Tarakina, N.V. |
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Title |
Tubular fullerenes inside carbon nanotubes : optimal molecular orientation versus tube radius |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
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Volume |
80 |
Issue |
3 |
Pages |
355-362 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
We present an investigation of the orientations and positions of tubular fullerene molecules (C90, ..., C200) encapsulated in single-walled carbon nanotubes (SWCNT), a series of so-called fullerene nanopeapods. We find that increasing the tube radius leads to the following succession of energetically stable regimes: (1) lying molecules positioned on the tube's long axis; (2) tilted molecules on the tube's long axis; and (3) lying molecules shifted away from the tube's long axis. As opposed to C70 and C80 molecules encapsulated in a SWCNT, standing orientations do not develop. Our results are relevant for the possible application of molecular-orientation-dependent electronic properties of fullerene nanopeapods, and also for the interpretation of future experiments on double-walled carbon nanotube formation by annealing fullerene peapod systems. |
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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 |
000289576200010 |
Publication Date |
2011-03-14 |
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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 |
1434-6028;1434-6036; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
1.461 |
Times cited |
10 |
Open Access |
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Notes |
; This work was financially supported by the Research Foundation – Flanders (FWO-VI). B.V. is a Postdoctoral Fellow of the Research Foundation – Flanders (FWO-VI). ; |
Approved |
Most recent IF: 1.461; 2011 IF: 1.534 |
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| |
Call Number |
UA @ lucian @ c:irua:89286 |
Serial |
3738 |
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| Permanent link to this record |
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Author |
Földi, P.; Szaszkó-Bogár, V.; Peeters, F.M. |
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Title |
High-temperature conductance of a two-dimensional superlattice controlled by spin-orbit interaction |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
11 |
Pages |
115313-115313,6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Rashba-type spin-orbit interaction (SOI) controlled band structure of a two-dimensional superlattice allows for the modulation of the conductance of finite size devices by changing the strength of the SOI. We consider rectangular arrays and find that the temperature dependence of the conductance disappears for high temperatures, but the strength of the SOI still affects the conductance at these temperatures. The modulation effect can be seen even in the presence of strong dephasing, which can be important for practical applications. |
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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 |
000288242800007 |
Publication Date |
2011-03-11 |
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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 |
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| |
Impact Factor |
3.836 |
Times cited |
8 |
Open Access |
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Notes |
; We thank M. G. Benedict and F. Bartha for useful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and M045596 and by the “TAMOP-4.2.1/B-09/1/KONV-2010-0005 project: Creating the Center of Excellence at the University of Szeged” supported by the EU and the European Regional Development Fund. P.F. was supported by a J. Bolyai grant of the Hungarian Academy of Sciences. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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| |
Call Number |
UA @ lucian @ c:irua:88778 |
Serial |
1466 |
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Author |
Carvalho, J.C.N.; Ferreira, W.P.; Farias, G.A.; Peeters, F.M. |
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Title |
Yukawa particles confined in a channel and subject to a periodic potential : ground state and normal modes |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
83 |
Issue |
9 |
Pages |
094109-094109,12 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We consider a classical system of two-dimensional (2D) charged particles, interacting through a repulsive Yukawa potential exp(-r/λ)/r, and confined in a parabolic channel that limits the motion of the particles in the y direction. Along the x direction, the particles are subject to a periodic potential. The ground-state configurations and the normal-mode spectra of the system are obtained as a function of the periodicity and strength of the periodic potential (V0) and density. An interesting set of tunable ground-state configurations are found, with first- or second-order structural transitions between them. A configuration with particles aligned, perpendicular to the x direction, in each minimum of the periodic potential is obtained for V0 larger than some critical value that has a power-law dependence on the density. The phonon spectrum of different configurations was also calculated. A localization of the modes into a small frequency interval is observed for sufficiently large strength of the periodic potential, and a tunable gap in the phonon spectrum is found as a function of V0. |
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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 |
000288119700001 |
Publication Date |
2011-03-08 |
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| |
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 |
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| |
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
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| |
Notes |
; This work was supported by the Brazilian agencies CNPq and FUNCAP (PRONEX-Grant), and the bilateral projects between Flanders and Brazil and the Flemish Science Foundation (FWO-VI) and CNPq. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:88779 |
Serial |
3928 |
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| Permanent link to this record |
