Records |
Author |
Vagov, A.; Croitoru, M.D.; Axt, V.M.; Kuhn, T.; Peeters, F. |
Title |
Real time path integrals in studies of quantum dots dynamics: non-monotonous decay rate and reappearance of rabi rotations |
Type |
P1 Proceeding |
Year |
2008 |
Publication |
Path Integrals : New Trends and Perspectives, Proceedings |
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
57-62 |
Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
Abstract |
The dynamics of strongly confined laser driven semiconductor quantum dots coupled to phonons is studied theoretically by calculating the time evolution of the reduced density matrix using the path integral method. We explore the cases of long pulses, strong dot-phonon and dot-laser coupling and high temperatures, which up to now have been inaccessible. We find that the decay rate of the Rabi oscillations is a non-monotonic function of the laser field leading to the decay and reappearance of the Rabi oscillations in the field dependence of the dot exciton population. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
World Scientific |
Place of Publication |
Singapore |
Editor |
|
Language |
|
Wos |
000264341000007 |
Publication Date |
2009-09-15 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:95702 |
Serial |
2834 |
Permanent link to this record |
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|
|
Author |
Zalipaev, V.; Linton, C.M.; Croitoru, M.D.; Vagov, A. |
Title |
Resonant tunneling and localized states in a graphene monolayer with a mass gap |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
91 |
Issue |
91 |
Pages |
085405 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We study tunneling of quasiparticles through potential barriers in a graphene monolayer with the mass gap using a semiclassical (WKB) approach. The main equations are derived in away similar to the WKB theory for the Schrodinger equation, which allows for explicit solutions at all orders. The analog of the classical action is used to distinguish types of possible stationary states in the system. The analysis focuses on the resonant scattering and the hole states localized in the vicinity of a barrier that are often overlooked. The scattering coefficients for the physically interesting limits are obtained by matching the WKB approximation with the known solutions at turning points. The localized states demonstrate unconventional properties and lead to alterations of the single particle density of states. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000351773900004 |
Publication Date |
2015-02-05 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
3 |
Open Access |
|
Notes |
; M.D.C. acknowledges the Belgian Science Policy (BELSPO Back to Belgium Grant). ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
Call Number |
c:irua:125523 |
Serial |
2891 |
Permanent link to this record |
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|
Author |
Shanenko, A.A.; Croitoru, M.D. |
Title |
Shape resonances in the superconducting order parameter of ultrathin nanowires |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
73 |
Issue |
1 |
Pages |
012510,1-4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
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Language |
|
Wos |
000235009000033 |
Publication Date |
2006-01-17 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
41 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2006 IF: 3.107 |
Call Number |
UA @ lucian @ c:irua:56613 |
Serial |
2990 |
Permanent link to this record |
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|
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Author |
Shanenko, A.A.; Croitoru, M.D.; Zgirski, M.; Peeters, F.M.; Arutyunov, K. |
Title |
Size-dependent enhancement of superconductivity in Al and Sn nanowires: shape-resonance effect |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
74 |
Issue |
5 |
Pages |
052502,1-4 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
Language |
|
Wos |
000240238400015 |
Publication Date |
2007-02-05 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
95 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2006 IF: 3.107 |
Call Number |
UA @ lucian @ c:irua:60806 |
Serial |
3034 |
Permanent link to this record |
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|
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Author |
van Dyck, D.; Croitoru, M.D. |
Title |
Statistical method for thickness measurement of amorphous objects |
Type |
A1 Journal article |
Year |
2007 |
Publication |
Applied physics letters |
Abbreviated Journal |
Appl Phys Lett |
Volume |
90 |
Issue |
24 |
Pages |
241911-241913 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT); Vision lab |
Abstract |
The authors propose a nondestructive method for the determination of the thickness of an amorphous sample. This method is based on the statistics of the phase of the electron exit wave function, which depend on the number of atoms traversed by the incident electron which itself is a function of the thickness of the object. The accuracy of this method has been checked numerically by the multislice method and compared with that based on the mean inner potential. (c) 2007 American Institute of Physics. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
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Wos |
000247305400033 |
Publication Date |
2007-06-14 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
ISSN |
0003-6951; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.411 |
Times cited |
4 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 3.411; 2007 IF: 3.596 |
Call Number |
UA @ lucian @ c:irua:102671 |
Serial |
3158 |
Permanent link to this record |
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Author |
Shanenko, A.A.; Croitoru, M.D.; Peeters, F.M. |
Title |
Superconducting nanofilms: Andreev-type states induced by quantum confinement |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
78 |
Issue |
5 |
Pages |
054505,1-054505,8 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT) |
Abstract |
Quantum confinement of the transverse electron motion is the major effect governing the superconducting properties of high-quality metallic nanofilms, leading to a nonuniform transverse distribution of the superconducting condensate. In this case the order parameter can exhibit significant local enhancements due to these quantum-size effects and, consequently, quasiparticles have lower energies when they avoid the local enhancements of the pair condensate. Such excitations can be considered as new Andreev-type quasiparticles but now induced by quantum confinement. By numerically solving the Bogoliubovde Gennes equations and using Anderson's approximate solution to these equations, we: (a) formulate a criterion for such new Andreev-type states (NATS) and (b) study their effect on the superconducting characteristics in metallic nanofilms. We also argue that nanofilms made of low-carrier-density materials, e.g., of superconducting semiconductors, can be a more optimal choice for the observations of NATS and other quantum-size superconducting effects. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000259368200109 |
Publication Date |
2008-08-11 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
14 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
Call Number |
UA @ lucian @ c:irua:76526 |
Serial |
3356 |
Permanent link to this record |
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Author |
Croitoru, M.D.; Shanenko, A.A.; Kaun, C.C.; Peeters, F.M. |
Title |
Superconducting nanowires: interplay of discrete transverse modes with supercurrent |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Physical review : B : solid state |
Abbreviated Journal |
Phys Rev B |
Volume |
80 |
Issue |
2 |
Pages |
024513,1-024513,11 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
From a numerical solution of the Bogoliubov-de Gennes equations, we investigate an interplay of the transverse discrete modes with a longitudinal supercurrent in a metallic cylindrical superconducting nanowire. The superconductor-to-normal transition induced by a longitudinal superflow of electrons is found to occur as a cascade of jumps in the order parameter (supercurrent and superfluid density) as a function of the superfluid velocity for diameters d<1015 nm (for Al parameters) and sufficiently low temperatures T<0.30.4Tc, with Tc the critical temperature. When approaching Tc, the jumps are smoothed into steplike but continuous drops. A similar picture occurs for d>1520 nm. Only when the diameter exceeds 5070 nm the quantum-size cascades are fully washed out, and we arrive at the mesoscopic regime. Below this regime the critical current density jc exhibits the quantum-size oscillations with pronounced resonant enhancements: the smaller the diameter, the more significant is the enhancement. Thickness fluctuations of real samples will smooth out such oscillations into an overall growth of jc with decreasing nanowire diameter. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000268617500092 |
Publication Date |
2009-07-22 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2009 IF: 3.475 |
Call Number |
UA @ lucian @ c:irua:77949 |
Serial |
3358 |
Permanent link to this record |
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|
Author |
Shanenko, A.A.; Croitoru, M.D.; Vagov, A.; Peeters, F.M. |
Title |
Superconducting nanowires : new type of BCS-BEC crossover driven by quantum-size effects |
Type |
P1 Proceeding |
Year |
2011 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
119-127 |
Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
Abstract |
We show that a superconducting quantum nanowire undergoes a new type of BCS-BEC crossover each time when an electron subband approaches the Fermi surface. In this case the longitudinal Cooper-pair size drops by two-three orders of magnitude down to a few nanometers. This unconventional BCS-BEC crossover is driven by quantum-size effects rather than by tuning the fermion-fermion interaction. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
Dordrecht |
Editor |
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Language |
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Wos |
000289872900009 |
Publication Date |
2010-12-11 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
1874-6500;1874-6535; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP) and the ESF-network: INSTANS. M.D.C. acknowledges support from the Alexander von Humboldt Foundation. ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:89946 |
Serial |
3359 |
Permanent link to this record |
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|
Author |
Chen, Y.; Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M. |
Title |
Superconducting nanowires: quantum confinement and spatially dependent Hartree-Fock potential |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
21 |
Issue |
43 |
Pages |
435701,1-435701,7 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
It is well known that, in bulk, the solution of the Bogoliubovde Gennes equations is the same whether or not the HartreeFock term is included. Here the HartreeFock potential is position independent and so gives the same contribution to both the single-electron energies and the Fermi level (the chemical potential). Thus, the single-electron energies measured from the Fermi level (they control the solution) stay the same. This is not the case for nanostructured superconductors, where quantum confinement breaks the translational symmetry and results in a position-dependent HartreeFock potential. In this case its contribution to the single-electron energies depends on the relevant quantum numbers. We numerically solved the Bogoliubovde Gennes equations with the HartreeFock term for a clean superconducting nanocylinder and found a shift of the curve representing the thickness-dependent oscillations of the critical superconducting temperature to larger diameters. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
|
Language |
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Wos |
000270642700012 |
Publication Date |
2009-10-09 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2009 IF: 1.964 |
Call Number |
UA @ lucian @ c:irua:79162 |
Serial |
3360 |
Permanent link to this record |
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|
|
Author |
Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M. |
Title |
Superconducting nanowires: quantum-confinement effect on the critical magnetic field and supercurrent |
Type |
P1 Proceeding |
Year |
2010 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
327-338 |
Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
Abstract |
We study the effect, of electron confinement on the superconducting-to-normal phase transition driven by a magnetic field and/or on the current-carrying state of the superconducting condensate in nanowires. Our investigation is based on a self-consistent. numerical solution of the Bogoliubov-de Gennes equations. We show that, in a parallel magnetic field and/or in the presence of supercurrent the transition from superconducting to normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magnetic held exhibits quantum-size oscillations with pronounced resonant enhancements. |
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 |
000278418300025 |
Publication Date |
2010-04-08 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), Interuni-versity Attraction Poles Programme -Belgian State -Belgian Science Policy (IAP) and the ESF-AQDJJ network. ; |
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:83294 |
Serial |
3361 |
Permanent link to this record |
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|
Author |
Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M. |
Title |
Superconducting nanowires: quantum-confinement effect on the critical magnetic field and supercurrent |
Type |
A1 Journal article |
Year |
2009 |
Publication |
International journal of modern physics: B: condensed matter physics, statistical physics, applied physics
T2 – 32nd International Workshop on Condensed Matter Theories, Aug 12-19, 2008, Loughborough Univ, Loughborough, England |
Abbreviated Journal |
Int J Mod Phys B |
Volume |
23 |
Issue |
20-21 |
Pages |
4257-4268 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT) |
Abstract |
We study the effect of electron confinement on the superconducting-to-normal phase transition driven by a magnetic field and/or on the current-carrying state of the superconducting condensate in nanowires. Our investigation is based on a self-consistent numerical solution of the Bogoliubov-de Gennes equations. We show that in a parallel magnetic field and/or in the presence of supercurrent the transition from superconducting to normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magnetic field exhibits quantum-size oscillations with pronounced resonant enhancements. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
World scientific |
Place of Publication |
Singapore |
Editor |
|
Language |
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Wos |
000274525500026 |
Publication Date |
2009-09-23 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0217-9792;1793-6578; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
0.736 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 0.736; 2009 IF: 0.408 |
Call Number |
UA @ lucian @ c:irua:95673 |
Serial |
3362 |
Permanent link to this record |
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|
|
Author |
Shanenko, A.A.; Croitoru, M.D.; Peeters, F.M. |
Title |
Superconductivity in the quantum-size regime |
Type |
P1 Proceeding |
Year |
2008 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
79-103 |
Keywords |
P1 Proceeding; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT) |
Abstract |
Recent technological advances resulted in high-quality superconducting metallic nanofilms and nanowires. The physical properties of such nanostructures are governed by the size-quantization of the transverse electron spectrum. This has a substantial impact on the basic superconducting characteristics, e.g., the order parameter, the critical temperature and the critical magnetic field. In the present paper we give an overview of our theoretical results on this subject. Based on a numerical self-consistent solution of the Bogoliubov-de Gennes equations, we investigate how the superconducting properties are modified in the quantum-size regime. |
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 |
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Publication Date |
0000-00-00 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
978-1-4020-9144-5 |
ISBN |
|
Additional Links |
UA library record; WoS full record; |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:75944 |
Serial |
3374 |
Permanent link to this record |
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|
|
Author |
Croitoru, M.D.; Vagov, A.; Shanenko, A.A.; Axt, V.M. |
Title |
The Cooper problem in nanoscale : enhancement of the coupling due to confinement |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
Volume |
25 |
Issue |
12 |
Pages |
124001-124005 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
In 1956 Cooper demonstrated (1956 Phys. Rev. 104 1189) that, no matter how weak the attraction is, two electrons in three-dimensional (3D) space just above the Fermi sea could be bound. In this work we investigate the influence of confinement on the binding energy of a Cooper pair. We show that confinement-induced modification of the Fermi sea results in a significant increase of the binding energy, when the bottom of an energy subband is very close to the Fermi surface. |
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 |
|
Language |
|
Wos |
000311418100004 |
Publication Date |
2012-11-08 |
Series Editor |
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Series Title ![sorted by Series Title field, ascending order (up)](img/sort_asc.gif) |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.878 |
Times cited |
9 |
Open Access |
|
Notes |
; MDC acknowledges support by the European Community under the Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR). ; |
Approved |
Most recent IF: 2.878; 2012 IF: 2.758 |
Call Number |
UA @ lucian @ c:irua:105121 |
Serial |
3573 |
Permanent link to this record |
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|
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Author |
Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M. |
Title |
Tuning the superconducting properties of nanomaterials |
Type |
H1 Book chapter |
Year |
2009 |
Publication |
|
Abbreviated Journal |
|
Volume |
|
Issue |
|
Pages |
1-14 |
Keywords |
H1 Book chapter; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT) |
Abstract |
Electron continement and its effect on the superconducting-to-normal phase transition driven by a magentic field and/or a current is studied in nanowires. Our investigation is based on a self-consistent numerical solution of the Bogoliubov-de Gennes equations. We find that in a parallel magneitc field and/or in the presence of a supercurrent the transition from the superconducting to the normal phase occurs as a cascade of discontinuous jumps in the superconducting order parameter for diameters D < 10 divided by 15 nm at T = 0. The critical magentic field exhibits quantum-size oscillations with pronounced resonant enhancements as a function of the wire radius. |
Address |
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Corporate Author |
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Thesis |
|
Publisher |
Springer |
Place of Publication |
Dordrecht |
Editor |
|
Language |
|
Wos |
000274282900001 |
Publication Date |
2009-07-29 |
Series Editor |
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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 |
1874-6500; |
ISBN |
978-90-481-3118-1 |
Additional Links |
UA library record; WoS full record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:99226 |
Serial |
3761 |
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Author |
Croitoru, M.D.; Shanenko, A.A.; Kaun, C.C.; Peeters, F.M. |
Title |
Ultra-small metallic grains : effect of statistical fluctuations of the chemical potential on superconducting correlations and vice versa |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
24 |
Issue |
27 |
Pages |
275701 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Superconducting correlations in an isolated metallic grain are governed by the interplay between two energy scales: the mean level spacing delta and the bulk pairing gap Delta(0), which are strongly influenced by the position of the chemical potential with respect to the closest single-electron level. In turn superconducting correlations affect the position of the chemical potential. Within the parity projected BCS model we investigate the probability distribution of the chemical potential in a superconducting grain with randomly distributed single-electron levels. Taking into account statistical fluctuations of the chemical potential due to the pairing interaction, we find that such fluctuations have a significant impact on the critical level spacing delta(c) at which the superconducting correlations cease: the critical ratio delta(c)/Delta(0) at which superconductivity disappears is found to be increased. |
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Corporate Author |
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Publisher |
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Place of Publication |
London |
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Wos |
000305653100012 |
Publication Date |
2012-06-21 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
9 |
Open Access |
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Notes |
; This work was supported by the European Community under the Marie Curie IEF Action (Grant Agreement No. PIEF-GA-2009-235486-ScQSR), the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), and the ESF network INSTANS. MDC and AAS are grateful to A Vagov for stimulating discussions. ; |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
Call Number |
UA @ lucian @ c:irua:100280 |
Serial |
3793 |
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Author |
Shanenko, A.A.; Aguiar, J.A.; Vagov, A.; Croitoru, M.D.; Milošević, M.V. |
Title |
Atomically flat superconducting nanofilms: multiband properties and mean-field theory |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
Volume |
28 |
Issue |
28 |
Pages |
054001 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Recent progress in materials synthesis enabled fabrication of superconducting atomically flat single-crystalline metallic nanofilms with thicknesses down to a few monolayers. Interest in such nano-thin systems is attracted by the dimensional 3D-2D crossover in their coherent properties which occurs with decreasing the film thickness. The first fundamental aspect of this crossover is dictated by the Mermin-Wagner-Hohenberg theorem and concerns frustration of the long-range order due to superconductive fluctuations and the possibility to track its impact with an unprecedented level of control. The second important aspect is related to the Fabri-Perot modes of the electronic motion strongly bound in the direction perpendicular to the nanofilm. The formation of such modes results in a pronounced multiband structure that changes with the nanofilm thickness and affects both the mean-field behavior and superconductive fluctuations. Though the subject is very rich in physics, it is scarcely investigated to date. The main obstacle is that there are no manageable models to study a complex magnetic response in this case. Full microscopic consideration is rather time consuming, if practicable at all, while the standard Ginzburg-Landau theory is not applicable. In the present work we review the main achievements in the subject to date, and construct and justify an efficient multiband mean-field formalism which allows for numerical and even analytical treatment of nano-thin superconductors in applied magnetic fields. |
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Place of Publication |
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Wos |
000353015700005 |
Publication Date |
2015-03-19 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0953-2048;1361-6668; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.878 |
Times cited |
23 |
Open Access |
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Notes |
This work was supported by the Brazilian agencies CNPq (grants 307552/2012-8 and 141911/2012-3) and FACEPE (APQ-0589-1.05/08). AAS acknowledges fruitful discussions with A Perali and D Neilson during his stay in the University of Camerino and is thankful for partial support of his visit by the University of Camerino under the project FAR 'Control and enhancement of superconductivity by engineering materials at the nanoscale'. MDC acknowledges the support from the Back to Belgium Grant of the federal Science Policy (BELSPO). |
Approved |
Most recent IF: 2.878; 2015 IF: 2.325 |
Call Number |
c:irua:132501 |
Serial |
3944 |
Permanent link to this record |
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Author |
Croitoru, M.D.; Shanenko, A.A.; Vagov, A.; Vasenko, A.S.; Milošević, M.V.; Axt, V.M.; Peeters, F.M. |
Title |
Influence of disorder on superconducting correlations in nanoparticles |
Type |
A1 Journal article |
Year |
2016 |
Publication |
Journal of superconductivity and novel magnetism |
Abbreviated Journal |
J Supercond Nov Magn |
Volume |
29 |
Issue |
29 |
Pages |
605-609 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We investigate how the interplay of quantum confinement and level broadening caused by disorder affects superconducting correlations in ultra-small metallic grains. We use the electron-phonon interaction-induced electron mass renormalization and the reduced static-path approximation of the BCS formalism to calculate the critical temperature as a function of the grain size. We show how the strong electron-impurity scattering additionally smears the peak structure in the electronic density of states of a metallic grain and imposes additional limits on the critical temperature under strong quantum confinement. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000371089500013 |
Publication Date |
2016-01-08 |
Series Editor |
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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 |
1557-1939 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.18 |
Times cited |
7 |
Open Access |
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Notes |
; This work was supported by the Belgian Science Policy (BELSPO Back to Belgium Grant), the Flemish Science Foundation (FWO-Vl), the Methusalem Foundation of the Flemish Government, TOPBOF-UA, and the bilateral project CNPq-FWO-Vl. ; |
Approved |
Most recent IF: 1.18 |
Call Number |
UA @ lucian @ c:irua:132286 |
Serial |
4195 |
Permanent link to this record |
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Author |
Croitoru, M.D.; Shanenko, A.A.; Vagov, A.; Milošević, M.V.; Axt, V.M.; Peeters, F.M. |
Title |
Phonon limited superconducting correlations in metallic nanograins |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
Volume |
5 |
Issue |
5 |
Pages |
16515 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Conventional superconductivity is inevitably suppressed in ultra-small metallic grains for characteristic sizes smaller than the Anderson limit. Experiments have shown that above the Anderson limit the critical temperature may be either enhanced or reduced when decreasing the particle size, depending on the superconducting material. In addition, there is experimental evidence that whether an enhancement or a reduction is found depends on the strength of the electronphonon interaction in the bulk. We reveal how the strength of the e-ph interaction interplays with the quantum-size effect and theoretically obtain the critical temperature of the superconducting nanograins in excellent agreement with experimental data. We demonstrate that strong e-ph scattering smears the peak structure in the electronic density-of-states of a metallic grain and enhances the electron mass, and thereby limits the highest T-c achievable by quantum confinement. |
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Publisher |
Nature Publishing Group |
Place of Publication |
London |
Editor |
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Wos |
000364647700001 |
Publication Date |
2015-11-13 |
Series Editor |
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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 |
2045-2322 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
4.259 |
Times cited |
9 |
Open Access |
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Notes |
; This work was supported by the Belgian Science Policy (BELSPO Back to Belgium Grant), the Research Foundation Flanders (FWO), the Methusalem Foundation of the Flemish Government, TOPBOF-UA, and the bilateral project CNPq-FWO. M.D.C. acknowledges fruitful discussions with V. Z. Kresin, S. N. Klimin and V. N. Gladilin. ; |
Approved |
Most recent IF: 4.259; 2015 IF: 5.578 |
Call Number |
UA @ lucian @ c:irua:129543 |
Serial |
4224 |
Permanent link to this record |
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Author |
Hannibal, S.; Kettmann, P.; Croitoru, M.D.; Vagov, A.; Axt, V.M.; Kuhn, T. |
Title |
Quench dynamics of an ultracold Fermi gas in the BCS regime : spectral properties and confinement-induced breakdown of the Higgs mode |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
Volume |
91 |
Issue |
91 |
Pages |
043630 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The Higgs amplitude mode of the order parameter of an ultracold confined Fermi gas in the BCS regime after a quench of the coupling constant is analyzed theoretically. A characteristic feature is a damped oscillation which at a certain transition time changes into a rather irregular dynamics. We compare the numerical solution of the full set of nonlinear equations of motion for the normal and anomalous Bogoliubov quasiparticle excitations with a linearized approximation. In doing so the transition time as well as the difference between resonant systems, i.e., systems where the Fermi energy is close to a sub-band minimum, and off-resonant systems can be well understood and traced back to the system and geometry parameters. |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Wos |
000353448500005 |
Publication Date |
2015-04-24 |
Series Editor |
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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 |
1094-1622; 1050-2947 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.925 |
Times cited |
10 |
Open Access |
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Notes |
; M.D.C. acknowledges support by the BELSPO Back to Belgium Grant. ; |
Approved |
Most recent IF: 2.925; 2015 IF: NA |
Call Number |
UA @ lucian @ c:irua:132509 |
Serial |
4235 |
Permanent link to this record |