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Records |
Links |
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Author |
Lukyanchuk, I.; Vinokur, V.M.; Rydh, A.; Xie, R.; Milošević, M.V.; Welp, U.; Zach, M.; Xiao, Z.L.; Crabtree, G.W.; Bending, S.J.; Peeters, F.M.; Kwok, W.K. |
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Title |
Rayleigh instability of confined vortex droplets in critical superconductors |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Nature physics |
Abbreviated Journal |
Nat Phys |
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| |
Volume |
11 |
Issue |
11 |
Pages |
21-25 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Depending on the Ginzburg-Landau parameter kappa, superconductors can either be fully diamagnetic if kappa < 1/root 2 (type I superconductors) or allow magnetic flux to penetrate through Abrikosov vortices if kappa > 1/root 2 (type II superconductors; refs 1,2). At the Bogomolny critical point, kappa = kappa(c) = 1/root 2, a state that is infinitely degenerate with respect to vortex spatial configurations arises(3,4). Despite in-depth investigations of conventional type I and type II superconductors, a thorough understanding of the magnetic behaviour in the near-Bogomolny critical regime at kappa similar to kappa(c) remains lacking. Here we report that in confined systems the critical regime expands over a finite interval of kappa forming a critical superconducting state. We show that in this state, in a sample with dimensions comparable to the vortex core size, vortices merge into a multi-quanta droplet, which undergoes Rayleigh instability(5) on increasing kappa and decays by emitting single vortices. Superconducting vortices realize Nielsen-Olesen singular solutions of the Abelian Higgs model, which is pervasive in phenomena ranging from quantum electrodynamics to cosmology(6-9). Our study of the transient dynamics of Abrikosov-Nielsen-Olesen vortices in systems with boundaries promises access to non-trivial effects in quantum field theory by means of bench-top laboratory experiments. |
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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 |
000346831100018 |
Publication Date |
2014-11-06 |
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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 |
|
Series Issue |
|
Edition |
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| |
ISSN  |
1745-2473;1745-2481; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
22.806 |
Times cited |
20 |
Open Access |
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Notes |
; We would like to thank N. Nekrasov for illuminating discussions. The work was supported by the US Department of Energy, Office of Science Materials Sciences and Engineering Division (V.M.V., W.K.K., U.W., R.X., M.Z., Z.L.X., G.W.C. and partially I.L. through the Materials Theory Institute), by FP7-IRSES-SIMTECH and ITN-NOTEDEV programs (I.L.), and by the Flemish Science Foundation (FWO-Vlaanderen) (M.V.M. and F.M.P.). ; |
Approved |
Most recent IF: 22.806; 2015 IF: 20.147 |
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| |
Call Number |
c:irua:122791 c:irua:122791 |
Serial |
2815 |
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| Permanent link to this record |
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Author |
Roditchev, D.; Brun, C.; Serrier-Garcia, L.; Cuevas, J.C.; Bessa, V.H.L.; Milošević, M.V.; Debontridder, F.; Stolyarov, V.; Cren, T. |
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Title |
Direct observation of Josephson vortex cores |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Nature physics |
Abbreviated Journal |
Nat Phys |
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| |
Volume |
11 |
Issue |
11 |
Pages |
332-337 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Superconducting correlations may propagate between two superconductors separated by a tiny insulating or metallic barrier, allowing a dissipationless electric current to flow(1,2). In the presence of a magnetic field, the maximum supercurrent oscillates(3) and each oscillation corresponding to the entry of one Josephson vortex into the barrier(4). Josephson vortices are conceptual blocks of advanced quantum devices such as coherent terahertz generators(5) or qubits for quantum computing(6), in which on-demand generation and control is crucial. Here, we map superconducting correlations inside proximity Josephson junctions(7) using scanning tunnelling microscopy. Unexpectedly, we find that such Josephson vortices have real cores, in which the proximity gap is locally suppressed and the normal state recovered. By following the Josephson vortex formation and evolution we demonstrate that they originate from quantum interference of Andreev quasiparticles(8), and that the phase portraits of the two superconducting quantum condensates at edges of the junction decide their generation, shape, spatial extent and arrangement. Our observation opens a pathway towards the generation and control of Josephson vortices by applying supercurrents through the superconducting leads of the junctions, that is, by purely electrical means without any need for a magnetic field, which is a crucial step towards high-density on-chip integration of superconducting quantum devices. |
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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 |
000352163100016 |
Publication Date |
2015-02-23 |
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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 |
1745-2473;1745-2481; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
22.806 |
Times cited |
102 |
Open Access |
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Notes |
T.C., C.B., F.D., V.S. and D.R. acknowledge financial support from the French ANR project and the French-Russian program PICS-CNRS/RAS. The authors also thank V. Cherkez for assistance during experiments and V. Vinokur (Argonne National Laboratory, Illinois USA) and A. Buzdin (University of Bordeaux 1, France) for stimulating discussions. J.C.C. acknowledges financial support from the Spanish MICINN (Contract No. FIS2011-28851-C1). V.H.L.B. acknowledges support from CNPq Brazil and productive discussions with Prof. A. Chaves (UFC, Brazil). M.V.M. acknowledges support from Research Foundation Flanders (FWO-Vlaanderen) and CAPES Brazil (PVE project BEX1392/11-5). |
Approved |
Most recent IF: 22.806; 2015 IF: 20.147 |
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Call Number |
c:irua:132524 c:irua:132524 |
Serial |
3943 |
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| Permanent link to this record |
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Author |
Partoens, B. |
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Title |
Spinorbit interactions : hide and seek |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Nature physics |
Abbreviated Journal |
Nat Phys |
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| |
Volume |
10 |
Issue |
|
Pages |
333-334 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
It is commonly believed that solids with spatial inversion symmetry do not display spinorbit effects. However, first-principles calculations now reveal unexpected spin structure for centrosymmetric crystals |
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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 |
000335371200003 |
Publication Date |
2014-04-11 |
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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 |
|
Edition |
|
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| |
ISSN |
1745-2473; 1745-2481 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
22.806 |
Times cited |
8 |
Open Access |
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Notes |
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Approved |
Most recent IF: 22.806; 2014 IF: 20.147 |
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Call Number |
UA @ lucian @ c:irua:141068 |
Serial |
4608 |
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| Permanent link to this record |
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Author |
Mao, J.; Jiang, Y.; Moldovan, D.; Li, G.; Watanabe, K.; Taniguchi, T.; Masir, M.R.; Peeters, F.M.; Andrei, E.Y. |
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Title |
Realization of a tunable artificial atom at a supercritically charged vacancy in graphene |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Nature physics |
Abbreviated Journal |
Nat Phys |
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| |
Volume |
12 |
Issue |
12 |
Pages |
545-549 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Graphene’s remarkable electronic properties have fuelled the vision of a graphene-based platform for lighter, faster and smarter electronics and computing applications. One of the challenges is to devise ways to tailor graphene’s electronic properties and to control its charge carriers. Here we show that a single-atom vacancy in graphene can stably host a local charge and that this charge can be gradually built up by applying voltage pulses with the tip of a scanning tunnelling microscope. The response of the conduction electrons in graphene to the local charge is monitored with scanning tunnelling and Landau level spectroscopy, and compared to numerical simulations. As the charge is increased, its interaction with the conduction electrons undergoes a transition into a supercritical regime where itinerant electrons are trapped in a sequence of quasi-bound states which resemble an artificial atom. The quasi-bound electron states are detected by a strong enhancement of the density of states within a disc centred on the vacancy site which is surrounded by halo of hole states. We further show that the quasi-bound states at the vacancy site are gate tunable and that the trapping mechanism can be turned on and off, providing a mechanism to control and guide electrons in graphene. |
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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 |
000377475700011 |
Publication Date |
2016-02-22 |
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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 |
1745-2473 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
22.806 |
Times cited |
93 |
Open Access |
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Notes |
; Funding was provided by DOE-FG02-99ER45742 (STM/STS), NSF DMR 1207108 (fabrication and characterization). Theoretical work supported by ESF-EUROCORES-EuroGRAPHENE, FWO-VI and Methusalem programme of the Flemish government. We thank V. F. Libisch, M. Pereira and E. Rossi for useful discussions. ; |
Approved |
Most recent IF: 22.806 |
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Call Number |
c:irua:134210 |
Serial |
4011 |
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| Permanent link to this record |
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Author |
Yang, W.; Misko, V.R.; Nelissen, K.; Kong, M.; Peeters, F.M. |
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Title |
Using self-driven microswimmers for particle separation |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Soft matter |
Abbreviated Journal |
Soft Matter |
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Volume |
8 |
Issue |
19 |
Pages |
5175-5179 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Microscopic self-propelled swimmers capable of autonomous navigation through complex environments provide appealing opportunities for localization, pick-up and delivery of micro and nanoscopic objects. Inspired by motile cells and bacteria, man-made microswimmers have been fabricated, and their motion in patterned surroundings has been experimentally studied. We propose to use self-driven artificial microswimmers for the separation of binary mixtures of colloids. We revealed different regimes of separation, including one with a velocity inversion. Our findings could be of use for various biological and medical 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 |
Cambridge |
Editor |
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Language |
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Wos |
000303208700009 |
Publication Date |
2012-03-26 |
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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 |
1744-683X;1744-6848; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.889 |
Times cited |
45 |
Open Access |
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Notes |
; This work was supported by the “Odysseus” Program of the Flemish Government and the Flemish Science Foundation (FWO-V1) (Belgium), the National Natural Science Foundation of China (No. 11047111), the State Key Program of National Natural Science of China (No. 51135007), the Research Fund for the Doctoral Program of Higher Education of China (No. 20111415120002), and the Major State Basic Research Development Program of China (973) (No. 2009CB724201). ; |
Approved |
Most recent IF: 3.889; 2012 IF: 3.909 |
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Call Number |
UA @ lucian @ c:irua:98326 |
Serial |
3826 |
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| Permanent link to this record |
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Author |
Doria, M.M.; de Romaguera, A.R.C.; Milošević, M.V.; Peeters, F.M. |
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Title |
Domain coexistence of magnetism and superconductivity : appearance of confined vortex loops |
Type |
P1 Proceeding |
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Year |
2008 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
97 |
Issue |
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Pages |
012070-012070,4 |
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Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
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Abstract |
A magnetic moment inside an extreme type II superconductor can have three, but not one or two, confined vortex loops near to the core. For a sub-micron superconducting particle the confined vortex loops eventually break up and reach the surface turning into external vortex pairs. |
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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 |
000276054100070 |
Publication Date |
2008-03-20 |
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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 |
1742-6596; |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
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Times cited |
|
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:99232 |
Serial |
747 |
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| Permanent link to this record |
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Author |
Escoffier, W.; Grigorieva, I.V.; Misko, V.R.; Baelus, B.J.; Peeters, F.M.; Vinnikov, L.Y.; Dubnos, S. |
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Title |
Formation of vortex clusters and giant vortices in mesoscopic superconducting disks with strong disorder |
Type |
A1 Journal article |
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Year |
2008 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
97 |
Issue |
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Pages |
012172,1-012172,6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Merged, or giant, multi-quanta vortices (GVs) appear in very small superconductors near the superconducting transition due to strong confinement of magnetic flux. Here we present evidence for a new, pinning-related, mechanism for vortex merger. Using Bitter decoration to visualise vortices in small Nb disks, we show that confinement in combination with strong disorder causes individual vortices to merge into clusters/GVs well below Tc and Hc2, in contrast to well-defined shells of individual vortices found in the absence of pinning. |
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Corporate Author |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000276054100171 |
Publication Date |
2008-03-20 |
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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 |
1742-6596; |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
|
Times cited |
|
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:82320 |
Serial |
1266 |
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| Permanent link to this record |
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Author |
Nguyen, N.T.T.; Peeters, F.M. |
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Title |
Phase-diagram for the magnetic states of the Mn-ion subsystem in a magnetic quantum dot |
Type |
P1 Proceeding |
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Year |
2010 |
Publication |
Journal of physics : conference series
T2 – Conference on Quantum Dots 2010 (QD2010), APR 26-30, 2010, Nottingham, ENGLAND |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
012032-12034 |
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Keywords |
P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The interplay between two types of spin-spin exchange interaction (namely of the electron with the Mn-ions and the Mn-ions with each other) that are governed by the positions of the Mn-ions and the magnetic field is studied in the case of a Mn-ion doped CdTe quantum dot. We investigate the formation of different magnetic phases and the existence of frustrated magnetic states due to the dominant contribution of the Mn-Mn energy. |
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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 |
000294907400032 |
Publication Date |
2010-09-21 |
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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 |
245 |
Series Issue |
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Edition |
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ISSN |
1742-6596; |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
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Times cited |
|
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:113081 |
Serial |
2582 |
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| Permanent link to this record |
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Author |
Nguyen, N.T.T.; Peeters, F.M. |
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Title |
The breakdown of Kohn's theorem in few-electron parabolic quantum dots doped with a single magnetic impurity Mn2+ |
Type |
P1 Proceeding |
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Year |
2010 |
Publication |
Journal of physics : conference series
T2 – Conference on Quantum Dots 2010 (QD2010), APR 26-30, 2010, Nottingham, ENGLAND |
Abbreviated Journal |
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Volume |
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Issue |
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Pages |
012031-12034 |
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Keywords |
P1 Proceeding; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The cyclotron resonance (CR) absorption spectrum is calculated for a II-VI parabolic quantum dot (QD) containing few electrons and a single magnetic dopant (Mn(2+)). We find that Kohn's theorem no longer holds for this system and that the CR spectrum depends on the number of electrons inside the QD. The electron-Mn-ion interaction strength can be tuned for example by the magnetic field and by moving the Mn-ion to different positions inside the QD. We demonstrate that due to the presence of the Mn-ion the relative motion of the electrons couple with their center-of-mass motion through the electron-Mn-ion spin-spin exchange term resulting in an electron-electron interaction dependence of the magneto-optical absorption spectrum. At the ferromagnetic-antiferromagnetic transition we observe significant discontinuities in the CR lines. |
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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 |
000294907400031 |
Publication Date |
2010-09-21 |
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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 |
245 |
Series Issue |
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Edition |
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ISSN |
1742-6596; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
|
Times cited |
1 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:113080 |
Serial |
3572 |
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Author |
Magnus, W.; Brosens, F.; Sorée, B. |
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Title |
Time dependent transport in 1D micro- and nanostructures: solving the Boltzmann and Wigner-Boltzmann equations |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
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Volume |
193 |
Issue |
1 |
Pages |
012004,1-012004,4 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
For many decades the Boltzmann distribution function has been used to calculate the non-equilibrium properties of mobile particles undergoing the combined action of various scattering mechanisms and externally applied force fields. When the latter give rise to the occurrence of inhomogeneous potential profiles across the region through which the particles are moving, the numerical solution of the Boltzmann equation becomes a highly complicated task. In this work we highlight a particular algorithm that can be used to solve the time dependent Boltzmann equation as well as its quantum mechanical extension, the WignerBoltzmann equation. As an illustration, we show the calculated distribution function describing electrons propagating under the action of both a uniform and a pronouncedly non-uniform electric field. |
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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 |
000277100400004 |
Publication Date |
2009-11-17 |
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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 |
1742-6596; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
2 |
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:82861 |
Serial |
3667 |
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Author |
Li, B.; Magnus, W.; Peeters, F.M. |
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Title |
Tunable exciton Aharonov-Bohm effect in a quantum ring |
Type |
A1 Journal article |
| |
Year |
2010 |
Publication |
Journal of physics : conference series
T2 – Proceedings of the 11th International Conference on Optics of Excitons in Confined Systems, September 7-11, 2009, Spain / Vina, L. [edit.]; et al. [edit.] |
Abbreviated Journal |
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Volume |
210 |
Issue |
1 |
Pages |
012030,1-01203,4 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We studied the optical Aharonov-Bohm effect for an exciton in a semiconductor quantum ring. A perpendicular electric field applied to a quantum ring with large height, is able to tune the exciton ground state energy such that it exhibits a weak observable Aharonov-Bohm oscillations. This Aharonov-Bohm effect is tunable in strength and period. |
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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 |
000289715800242 |
Publication Date |
2010-03-03 |
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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 |
1742-6596; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
3 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:89950 |
Serial |
3741 |
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| Permanent link to this record |
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| |
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Author |
Saniz, R.; Vercauteren, S.; Lamoen, D.; Partoens, B.; Barbiellini, B. |
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| |
Title |
Accurate description of the van der Waals interaction of an electron-positron pair with the surface of a topological insulator |
Type |
P1 Proceeding |
| |
Year |
2014 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
|
| |
Volume |
505 |
Issue |
|
Pages |
012002 |
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| |
Keywords |
P1 Proceeding; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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| |
Abstract |
Positrons can be trapped in localized states at the surface of a material, and thus quite selectively interact with core or valence surface electrons. Hence, advanced surface positron spectroscopy techniques can present the ideal tools to study a topological insulator, where surface states play a fundamental role. We analyze the problem of a positron at a TI surface, assuming that it is a weakly physisorbed positronium (Ps) atom. To determine if the surface of interest in a material can sustain such a physisorption, an accurate description of the underlying van der Waals (vdW) interaction is essential. We have developed a first-principles parameterfree method, based on the density functional theory, to extract key parameters determining the vdW interaction potential between a Ps atom and the surface of a given material. The method has been successfully applied to quartz and preliminary results on Bi2Te2Se indicate the existence of a positron surface state. We discuss the robustness of our predictions versus the most relevant approximations involved in our approach. |
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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 |
000338216500002 |
Publication Date |
2014-04-28 |
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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 |
|
Edition |
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| |
ISSN |
1742-6588;1742-6596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
2 |
Open Access |
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| |
Notes |
; We thank A. Weiss for very useful conversations. We acknowledge financial support from FWO-Vlaanderen (projectG.0150.13). This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), adivision of the Flemish Supercomputer Center (VSC), funded by the Hercules foundation and the Flemish Government (EWI Department). B. B. is supported by DOE grants Nos. DE-FG02-07ER46352 and DE-AC02-05CH11231 for theory support at ALS, Berkeley, and a NERSC computer time allocation. ; |
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:118264 |
Serial |
46 |
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| Permanent link to this record |
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| |
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Author |
Engbarth, M.; Milošević, M.V.; Bending, S.J.; Nasirpouri, F. |
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| |
Title |
Geometry-guided flux behaviour in superconducting Pb microcrystals |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
|
| |
Volume |
150 |
Issue |
5 |
Pages |
052048 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Electrochemistry offers highly flexible routes to fabrication of a wide variety of mesostructures, including three-dimensional (3D) crystallites, thin films and nanowires. Using this method we have grown various 3D superconducting Pb mesostructures with vastly different morphologies. We present here results on a truncated(half)-icosahedron with a hexagonal base and a tripod structure with a triangular base. Using Hall probe magnetometry we have obtained magnetisation curves for these structures at several temperatures and see evidence of geometry-driven flux entry and exit as well as flux trapping caused by specific sample geometries. We also observe behaviour that we interpret in terms of the formation of giant vortices, bearing in mind that bulk Pb is a type-I superconducting material. |
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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 |
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Publication Date |
2009-04-01 |
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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 |
1742-6588;1742-6596; |
ISBN |
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Additional Links |
UA library record |
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| |
Impact Factor |
|
Times cited |
1 |
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:106138 |
Serial |
1332 |
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| Permanent link to this record |
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| |
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Author |
Benedict, M.G.; Földi, P.; Peeters, F.M. |
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| |
Title |
Terahertz radiation from crystals of nanomagnets |
Type |
P1 Proceeding |
| |
Year |
2006 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
|
| |
Volume |
36 |
Issue |
|
Pages |
12-17 |
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| |
Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
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Abstract |
Certain crystals, consisting of molecules with unusually large spin, exhibit macroscopically observable signatures of quantum tunneling, when a slowly varying external magnetic field is applied parallel to the easy axis of the crystal. Recently it has been observed that jumps in the magnetization are sometimes accompanied by the emission of infrared radiation. We discuss the connection of the tunneling with the electromagnetic transition, and we address the questions: to what extent can the radiation be considered as a collective, superradiant emission, and what is the role played by the cavity in the experiments? Our conclusion is that among the reported experimental coditions the radiation is not superradidance, but rather a maserlike 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 |
Bristol |
Editor |
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| |
Language |
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Wos |
000239847500003 |
Publication Date |
2006-05-04 |
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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 |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1742-6588;1742-6596; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
1 |
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:94695 |
Serial |
3508 |
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| Permanent link to this record |
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Author |
Baelus, B.J.; Kanda, A.; Peeters, F.M.; Ootuka, Y.; Kadowaki, K. |
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Title |
Two kinds of vortex states in thin mesoscopic superconductors |
Type |
A1 Journal article |
| |
Year |
2006 |
Publication |
Journal of physics : conference series
T2 – Journal of physics: conference series |
Abbreviated Journal |
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| |
Volume |
43 |
Issue |
|
Pages |
647-650 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Experimentally, multivortex states and giant vortex states in mesoscopic superconductors can be distinguished directly by using the multiple-small-tunnel-junctions, and indirectly by studying the temperature dependence of the expulsion fields. These experimental results are compared with the theoretical prediction from the nonlinear Ginzburg- Landau theory. |
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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 |
000277479400158 |
Publication Date |
2006-07-21 |
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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 |
|
Edition |
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| |
ISSN |
1742-6588;1742-6596; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
|
Times cited |
|
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:82762 |
Serial |
3782 |
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| Permanent link to this record |
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| |
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Author |
Bending, S.J.; Neal, J.S.; Milošević, M.V.; Potenza, A.; san Emeterio, L.; Marrows, C.H. |
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| |
Title |
Vortex-antivortex 'molecular crystals' in hybrid ferromagnet/superconductor structures |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
|
| |
Volume |
150 |
Issue |
5 |
Pages |
052019 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We have used high resolution Hall probe microscopy to image vortex-antivortex (V-AV) 'molecules' induced in superconducting Pb films by the stray fields from square arrays of ferromagnetic Co/Pt dots. We have directly observed spontaneous V-AV pairs and studied how they interact with added 'free' (anti)fluxons in an applied magnetic field. We observe a rich variety of subtle phenomena arising from competing symmetries in our system which can either drive added antivortices to join AV shells around nanomagnets or stabilise the translationally symmetric AV lattice between the dots. Added vortices annihilate AV shells, leading eventually to a stable 'nulling' state with no free fluxons, which should exhibit a strongly (field-)enhanced critical current. At higher densities we actually observe vortex shells around the magnets, stabilised by the asymmetric anti-pinning potential. Our experimental findings are in good agreement with Ginzburg-Landau 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 |
Bristol |
Editor |
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Language |
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Wos |
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Publication Date |
2009-04-01 |
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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 |
1742-6588;1742-6596; |
ISBN |
|
Additional Links |
UA library record |
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| |
Impact Factor |
|
Times cited |
|
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:106136 |
Serial |
3855 |
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| Permanent link to this record |
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| |
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Author |
Connolly, M.R.; Milošević, M.V.; Bending, S.J.; Clem, J.R.; Tamegai, T. |
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| |
Title |
Vortex 'puddles' and magic vortex numbers in mesoscopic superconducting disks |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
|
| |
Volume |
150 |
Issue |
5 |
Pages |
052039 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
The magnetic properties of a superconducting disk change dramatically when its dimensions become mesoscopic. Unlike large disks, where the screening currents induced by an applied magnetic field are strong enough to force vortices to accumulate in a 'puddle' at the centre, in a mesoscopic disk the interaction between one of these vortices and the edge currents can be comparable to the intervortex repulsion, resulting in a destruction of the ordered triangular vortex lattice structure at the centre. Vortices instead form clusters which adopt polygonal and shell-like structures which exhibit magic number states similar to those of charged particles in a confining potential, and electrons in artificial atoms. We have fabricated mesoscopic high temperature superconducting Bi2Sr2CaCu2O8+δ disks and investigated their magnetic properties using magneto-optical imaging (MOI) and high resolution scanning Hall probe microscopy (SHPM). The temperature dependence of the vortex penetration field measured using MOI is in excellent agreement with models of the thermal excitation of pancake vortices over edge barriers. The growth of the central vortex puddle has been directly imaged using SHPM and magic vortex numbers showing higher stability have been correlated with abrupt jumps in the measured local magnetisation curves. |
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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 |
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Publication Date |
2009-04-01 |
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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 |
1742-6588;1742-6596; |
ISBN |
|
Additional Links |
UA library record |
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| |
Impact Factor |
|
Times cited |
|
Open Access |
|
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| |
Notes |
|
Approved |
Most recent IF: NA |
|
| |
Call Number |
UA @ lucian @ c:irua:106137 |
Serial |
3881 |
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| Permanent link to this record |
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| |
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Author |
Neilson, D.; Perali, A.; Zarenia, M. |
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| |
Title |
Many-body electron correlations in graphene |
Type |
P1 Proceeding |
| |
Year |
2016 |
Publication |
(mbt18) |
Abbreviated Journal |
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|
| |
Volume |
702 |
Issue |
702 |
Pages |
012008 |
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| |
Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
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| |
Abstract |
The conduction electrons in graphene promise new opportunities to access the region of strong many-body electron-electron correlations. Extremely high quality, atomically flat two-dimensional electron sheets and quasi-one-dimensional electron nanoribbons with tuneable band gaps that can be switched on by gates, should exhibit new many-body phenomena that have long been predicted for the regions of phase space where the average Coulomb repulsions between electrons dominate over their Fermi energies. In electron nanoribbons a few nanometres wide etched in monolayers of graphene, the quantum size effects and the van Hove singularities in their density of states further act to enhance electron correlations. For graphene multilayers or nanoribbons in a double unit electron-hole geometry, it is possible for the many-body electron-hole correlations to be made strong enough to stabilise high-temperature electron- hole superfluidity. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
Iop publishing ltd |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000389756000008 |
Publication Date |
2016-04-29 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
702 |
Series Issue |
|
Edition |
|
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| |
ISSN |
1742-6588; 1742-6596 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
3 |
Open Access |
|
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| |
Notes |
; ; |
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:140268 |
Serial |
4455 |
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| Permanent link to this record |
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Author |
Callewaert, V.; Saniz, R.; Barbiellini, B.; Partoens, B. |
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Title |
Surface states and positron annihilation spectroscopy: results and prospects from a first-principles approach |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
|
| |
Volume |
791 |
Issue |
791 |
Pages |
012036 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
The trapping of positrons at the surface of a material can be exploited to study quite selectively the surface properties of the latter by means of positron annihilation spectroscopy techniques. To support these, it is desirable to be able to theoretically predict the existence of such positronic surface states and to describe their annihilation characteristics with core or valence surface electrons in a reliable way. Here, we build on the well-developed first-principles techniques for the study of positrons in bulk solids as well as on previous models for surfaces, and investigate two schemes that can improve the theoretical description of the interaction of positrons with surfaces. One is based on supplementing the local-density correlation potential with the corrugated image potential at the surface, and the other is based on the weighted-density approximation to correlation. We discuss our results for topological insulators, graphene layers, and quantum dots, with emphasis on the information that can be directly related to experiment. We also discuss some open theoretical problems that should be addressed by future research. |
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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 |
000400610500036 |
Publication Date |
2017-02-22 |
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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 |
1742-6588 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
1 |
Open Access |
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| |
Notes |
We acknowledge financial support from FWO-Vlaanderen (projects G.0150.13 and G.0224.14N). This work was carried out using the HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), funded by the Hercules foundation and the Flemish Government (EWI Department). The work at Northeastern University was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-FG02-07ER46352 (core research), and benefited from Northeastern University’s Advanced Scientific Computation Center (ASCC), the NERSC supercomputing center through DOE grant number DE-AC02- 05CH11231, and support (applications to layered materials) from the DOE EFRC: Center for the Computational Design of Functional Layered Materials (CCDM) under DE-SC0012575. |
Approved |
Most recent IF: NA |
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| |
Call Number |
CMT @ cmt @ c:irua:140847 |
Serial |
4425 |
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| Permanent link to this record |
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Author |
Eijt, S.W.H.; Shi, W.; Mannheim, A.; Butterling, M.; Schut, H.; Egger, W.; Dickmann, M.; Hugenschmidt, C.; Shakeri, B.; Meulenberg, R.W.; Callewaert, V.; Saniz, R.; Partoens, B.; Barbiellini, B.; Bansil, A.; Melskens, J.; Zeman, M.; Smets, A.H.M.; Kulbak, M.; Hodes, G.; Cahen, D.; Brück, E. |
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Title |
New insights into the nanostructure of innovative thin film solar cells gained by positron annihilation spectroscopy |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Journal of physics : conference series |
Abbreviated Journal |
|
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| |
Volume |
791 |
Issue |
791 |
Pages |
012021 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Recent studies showed that positron annihilation methods can provide key insights into the nanostructure and electronic structure of thin film solar cells. In this study, positron annihilation lifetime spectroscopy (PALS) is applied to investigate CdSe quantum dot (QD) light absorbing layers, providing evidence of positron trapping at the surfaces of the QDs. This enables one to monitor their surface composition and electronic structure. Further, 2D-Angular Correlation of Annihilation Radiation (2D-ACAR) is used to investigate the nanostructure of divacancies in photovoltaic-high-quality a-Si:H films. The collected momentum distributions were converted by Fourier transformation to the direct space representation of the electron-positron autocorrelation function. The evolution of the size of the divacancies as a function of hydrogen dilution during deposition of a-Si:H thin films was examined. Finally, we present a first positron Doppler Broadening of Annihilation Radiation (DBAR) study of the emerging class of highly efficient thin film solar cells based on perovskites. |
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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 |
000400610500021 |
Publication Date |
2017-02-22 |
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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 |
1742-6588 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
1 |
Open Access |
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Notes |
The work at Delft University of Technology was supported by the China Scholarship Council (CSC) grant of W.S., by ADEM, A green Deal in Energy Materials of the Ministry of Economic Affairs of The Netherlands (www.adem- innovationlab.nl), and the STW Vidi grant of A.S., Grant No. 10782. The PALS study is based upon experiments performed at the PLEPS instrument of the NEPOMUC facility at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany, and was supported by the European Commission under the 7 th Framework Programme, Key Action: Strengthening the European Research Area, Research Infrastructures, Contract No. 226507, NMI3. The work at University of Maine was supported by the National Science Foundation under Grant No. DMR-1206940. Research at the University of Antwerp was supported by FWO grants G022414N and G015013. The work at Northeastern University was supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences grant number DE-FG02-07ER46352 (core research), and benefited from Northeastern University's Advanced Scientific Computation Center (ASCC), the NERSC supercomputing center through DOE grant number DE-AC02-05CH11231, and support (applications to layered materials) from the DOE EFRC: Center for the Computational Design of Functional Layered Materials (CCDM) under DE-SC0012575. The work at the Weizmann Institute was supported by the Sidney E. Frank Foundation through the Israel Science Foundation, by the Israel Ministry of Science, and the Israel National Nano-Initiative. D.C. holds the Sylvia and Rowland Schaefer Chair in Energy Research. |
Approved |
Most recent IF: NA |
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| |
Call Number |
CMT @ cmt @ c:irua:140850 |
Serial |
4426 |
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| Permanent link to this record |
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Author |
McLachlan, G.; Majdak, P.; Reijniers, J.; Mihocic, M.; Peremans, H. |
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Title |
Dynamic spectral cues do not affect human sound localization during small head movements |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Frontiers in neuroscience |
Abbreviated Journal |
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| |
Volume |
17 |
Issue |
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Pages |
1027827-10 |
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Keywords |
A1 Journal article; Psychology; Condensed Matter Theory (CMT); Engineering Management (ENM) |
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| |
Abstract |
Natural listening involves a constant deployment of small head movement. Spatial listening is facilitated by head movements, especially when resolving front-back confusions, an otherwise common issue during sound localization under head-still conditions. The present study investigated which acoustic cues are utilized by human listeners to localize sounds using small head movements (below ±10° around the center). Seven normal-hearing subjects participated in a sound localization experiment in a virtual reality environment. Four acoustic cue stimulus conditions were presented (full spectrum, flattened spectrum, frozen spectrum, free-field) under three movement conditions (no movement, head rotations over the yaw axis and over the pitch axis). Localization performance was assessed using three metrics: lateral and polar precision error and front-back confusion rate. Analysis through mixed-effects models showed that even small yaw rotations provide a remarkable decrease in front-back confusion rate, whereas pitch rotations did not show much of an effect. Furthermore, MSS cues improved localization performance even in the presence of dITD cues. However, performance was similar between stimuli with and without dMSS cues. This indicates that human listeners utilize the MSS cues before the head moves, but do not rely on dMSS cues to localize sounds when utilizing small head movements. |
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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 |
000938567400001 |
Publication Date |
2023-02-03 |
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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 |
1662-4548; 1662-453x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:194507 |
Serial |
9025 |
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Author |
Yu, H.; Kopach, A.; Misko, V.R.; Vasylenko, A.A.; Makarov, D.; Marchesoni, F.; Nori, F.; Baraban, L.; Cuniberti, G. |
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Title |
Confined Catalytic Janus Swimmers in a Crowded Channel: Geometry-Driven Rectification Transients and Directional Locking |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Small |
Abbreviated Journal |
Small |
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Volume |
12 |
Issue |
12 |
Pages |
5882-5890 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Self-propelled Janus particles, acting as microscopic vehicles, have the potential to perform complex tasks on a microscopic scale, suitable, e.g., for environmental applications, on-chip chemical information processing, or in vivo drug delivery. Development of these smart nanodevices requires a better understanding of how synthetic swimmers move in crowded and confined environments that mimic actual biosystems, e.g., network of blood vessels. Here, the dynamics of self-propelled Janus particles interacting with catalytically passive silica beads in a narrow channel is studied both experimentally and through numerical simulations. Upon varying the area density of the silica beads and the width of the channel, active transport reveals a number of intriguing properties, which range from distinct bulk and boundary-free diffusivity at low densities, to directional “locking” and channel “unclogging” at higher densities, whereby a Janus swimmer is capable of transporting large clusters of passive particles. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Weinheim |
Editor |
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Language |
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Wos |
000389403900010 |
Publication Date |
2016-09-15 |
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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 |
1613-6810 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.643 |
Times cited |
14 |
Open Access |
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Notes |
; H.Y., A.K., and L.B. contributed equally to this work. This work was funded in part by the European Union (ERDF) and the Free State of Saxony via the ESF project InnoMedTec, the DFG cluster for Excellence, the Center for Advancing Electronics Dresden (CfAED), and via the European Research Council under the European Union's Seventh Framework program (FP7/2007-2013)/ERC grant agreement no. 306277. V.R.M. and A.A.V. acknowledge support from the Odysseus Program of the Flemish Government and the FWO-VI. F.N. is partially supported by the RIKEN iTHES Project, the MURI Center for Dynamic Magneto-Optics via the AFOSR Grant No. FA9550-14-1-0040, the IMPACT program of the JST, and a Grant-in-Aid for the Scientific Research (A). ; |
Approved |
Most recent IF: 8.643 |
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Call Number |
UA @ lucian @ c:irua:140256 |
Serial |
4453 |
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Author |
Castelano, L.K.; Hai, G.-Q.; Partoens, B.; Peeters, F.M. |
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Title |
Ground state configurations of vertically coupled quantum rings |
Type |
A1 Journal article |
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Year |
2007 |
Publication |
Physica status solidi: C: conferences and critical reviews |
Abbreviated Journal |
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Volume |
4 |
Issue |
2 |
Pages |
560-562 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
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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 |
000245877200097 |
Publication Date |
2007-02-07 |
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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 |
1610-1634;1610-1642; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:69665 |
Serial |
1386 |
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Author |
Sorée, B.; Magnus, W.; Pourtois, G. |
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Title |
Analytical and self-consistent quantum mechanical model for a surrounding gate MOS nanowire operated in JFET mode |
Type |
A1 Journal article |
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Year |
2008 |
Publication |
Journal of computational electronics |
Abbreviated Journal |
J Comput Electron |
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Volume |
7 |
Issue |
3 |
Pages |
380-383 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
We derive an analytical model for the electrostatics and the drive current in a silicon nanowire operating in JFET mode. We show that there exists a range of nanowire radii and doping densities for which the nanowire JFET satisfies reasonable device characteristics. For thin nanowires we have developed a self-consistent quantum mechanical model to obtain the electronic structure. |
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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 |
S.l. |
Editor |
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Language |
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Wos |
000208473800067 |
Publication Date |
2008-02-20 |
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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 |
1569-8025;1572-8137; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.526 |
Times cited |
70 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.526; 2008 IF: NA |
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Call Number |
UA @ lucian @ c:irua:89504 |
Serial |
107 |
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Author |
Slachmuylders, A.; Partoens, B.; Magnus, W.; Peeters, F.M. |
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Title |
The effect of dielectric mismatch on excitons and trions in cylindrical semiconductor nanowires |
Type |
A1 Journal article |
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Year |
2008 |
Publication |
Journal of computational electronics |
Abbreviated Journal |
J Comput Electron |
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Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
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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 |
S.l. |
Editor |
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Language |
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Wos |
000208473800066 |
Publication Date |
2008-02-19 |
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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 |
1569-8025;1572-8137; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.526 |
Times cited |
2 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.526; 2008 IF: NA |
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Call Number |
UA @ lucian @ c:irua:69620 |
Serial |
808 |
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Author |
Pourghaderi, M.A.; Magnus, W.; Sorée, B.; de Meyer, K.; Meuris, M.; Heyns, M. |
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Title |
General 2D Schrödinger-Poisson solver with open boundary conditions for nano-scale CMOS transistors |
Type |
A1 Journal article |
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Year |
2008 |
Publication |
Journal of computational electronics |
Abbreviated Journal |
J Comput Electron |
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Volume |
7 |
Issue |
4 |
Pages |
475-484 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Employing the quantum transmitting boundary (QTB) method, we have developed a two-dimensional Schrödinger-Poisson solver in order to investigate quantum transport in nano-scale CMOS transistors subjected to open boundary conditions. In this paper we briefly describe the building blocks of the solver that was originally written to model silicon devices. Next, we explain how to extend the code to semiconducting materials such as germanium, having conduction bands with energy ellipsoids that are neither parallel nor perpendicular to the channel interfaces or even to each other. The latter introduces mixed derivatives in the 2D effective mass equation, thereby heavily complicating the implementation of open boundary conditions. We present a generalized quantum transmitting boundary method that mainly leans on the completeness of the eigenstates of the effective mass equation. Finally, we propose a new algorithm to calculate the chemical potentials of the source and drain reservoirs, taking into account their mutual interaction at high drain voltages. As an illustration, we present the potential and carrier density profiles obtained for a (111) Ge NMOS transistor as well as the ballistic current characteristics. |
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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 |
S.l. |
Editor |
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Language |
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Wos |
000209032500002 |
Publication Date |
2008-09-02 |
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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 |
1569-8025;1572-8137; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.526 |
Times cited |
3 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.526; 2008 IF: NA |
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Call Number |
UA @ lucian @ c:irua:89505 |
Serial |
1322 |
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Author |
Magnus, W.; Brosens, F.; Sorée, B. |
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Title |
Modeling drive currents and leakage currents : a dynamic approach |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Journal of computational electronics |
Abbreviated Journal |
J Comput Electron |
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Volume |
8 |
Issue |
3/4 |
Pages |
307-323 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
The dynamics of electrons and holes propagating through the nano-scaled channels of modern semiconductor devices can be seen as a widespread manifestation of non-equilibrium statistical physics and its ruling principles. In this respect both the devices that are pushing conventional CMOS technology towards the final frontiers of Moores law and the upcoming set of alternative, novel nanostructures grounded on entirely new concepts and working principles, provide an almost unlimited playground for assessing physical models and numerical techniques emerging from classical and quantum mechanical non-equilibrium theory. In this paper we revisit the Boltzmann as well as the WignerBoltzmann equation which offers a valuable platform to study transport of charge carriers taking part in drive currents. We focus on a numerical procedure that regained attention recently as an alternative tool to solve the time-dependent Boltzmann equation for inhomogeneous systems, such as the channel regions of field-effect transistors, and we discuss its extension to the WignerBoltzmann equation. Furthermore, we pay attention to the calculation of tunneling leakage currents. The latter typically occurs in nano-scaled transistors when part of the carrier distribution sustaining the drive current is found to tunnel into the gate due the presence of an ultra-thin insulating barrier separating the gate from the channel region. In particular, we discuss the paradox related to the very existence of leakage currents established by electrons occupying quasi-bound states, while the (real) wave functions of the latter cannot carry net currents. Finally, we describe a simple model to resolve the paradox as well as to estimate gate currents provided the local carrier generation rates largely exceed the tunneling rates. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
S.l. |
Editor |
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Language |
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Wos |
000208236100009 |
Publication Date |
2009-09-28 |
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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 |
1569-8025;1572-8137; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.526 |
Times cited |
4 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.526; 2009 IF: NA |
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Call Number |
UA @ lucian @ c:irua:89503 |
Serial |
2110 |
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Author |
Sorée, B.; Magnus, W. |
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Title |
Quantized conductance without reservoirs : method of the nonequilibrium statistical operator |
Type |
A1 Journal article |
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Year |
2007 |
Publication |
Journal of computational electronics |
Abbreviated Journal |
J Comput Electron |
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Volume |
6 |
Issue |
1/3 |
Pages |
255-258 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We introduce a generalized non-equilibrium statistical operator (NSO) to study a current-carrying system. The NSO is used to derive a set of quantum kinetic equations based on quantum mechanical balance equations. The quantum kinetic equations are solved self-consistently together with Poissons equation to solve a general transport problem. We show that these kinetic equations can be used to rederive the Landauer formula for the conductance of a quantum point contact, without any reference to reservoirs at different chemical potentials. Instead, energy dissipation is taken into account explicitly through the electron-phonon interaction. We find that both elastic and inelastic scattering are necessary to obtain the Landauer conductance. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
S.l. |
Editor |
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Language |
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Wos |
000208473600062 |
Publication Date |
2007-01-17 |
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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 |
1569-8025;1572-8137; |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
1.526 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 1.526; 2007 IF: NA |
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Call Number |
UA @ lucian @ c:irua:89506 |
Serial |
2769 |
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Author |
Sels, D.; Sorée, B.; Groeseneken, G. |
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Title |
Quantum ballistic transport in the junctionless nanowire pinch-off field effect transistor |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Journal of computational electronics |
Abbreviated Journal |
J Comput Electron |
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Volume |
10 |
Issue |
1 |
Pages |
216-221 |
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Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
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Abstract |
In this work we investigate quantum ballistic transport in ultrasmall junctionless and inversion mode semiconducting nanowire transistors within the framework of the self-consistent Schrödinger-Poisson problem. The quantum transmitting boundary method is used to generate open boundary conditions between the active region and the electron reservoirs. We adopt a subband decomposition approach to make the problem numerically tractable and make a comparison of four different numerical approaches to solve the self-consistent Schrödinger-Poisson problem. Finally we discuss the IV-characteristics for small (r≤5 nm) GaAs nanowire transistors. The novel junctionless pinch-off FET or junctionless nanowire transistor is extensively compared with the gate-all-around (GAA) nanowire MOSFET. |
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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 |
S.l. |
Editor |
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Language |
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Wos |
000300735800021 |
Publication Date |
2011-02-22 |
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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 |
1569-8025;1572-8137; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.526 |
Times cited |
12 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 1.526; 2011 IF: 1.211 |
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Call Number |
UA @ lucian @ c:irua:89501 |
Serial |
2772 |
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Author |
Masir, M.R.; Peeters, F.M. |
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Title |
Scattering of Dirac electrons by a random array of magnetic flux tubes |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Journal of computational electronics |
Abbreviated Journal |
J Comput Electron |
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Volume |
12 |
Issue |
2 |
Pages |
115-122 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The scattering of two-dimensional (2D) massless electrons as presented in graphene in the presence of a random array of circular magnetic flux tubes is investigated. The momentum relaxation time and the Hall factor are obtained using optical theorem techniques for scattering. Electrons with energy close to those of the Landau levels of the flux tubes exhibit resonant scattering and have a long life-time to reside inside the magnetic flux tube. These resonances appear as sharp structures in the Hall factor and the magneto-resistance. |
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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 |
S.l. |
Editor |
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Language |
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Wos |
000320044900007 |
Publication Date |
2013-02-15 |
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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 |
1569-8025;1572-8137; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.526 |
Times cited |
2 |
Open Access |
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Notes |
; This work was supported by the European Science Foundation (ESF) under the EUROCORES Program Euro-GRAPHENE within the project CONGRAN and the Flemish Science Foundation (FWO-Vl). We acknowledge fruitful discussions with A. Matulis. ; |
Approved |
Most recent IF: 1.526; 2013 IF: 1.372 |
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Call Number |
UA @ lucian @ c:irua:109615 |
Serial |
2950 |
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