Records |
Author |
Ivanov, V.A.; Betouras, J.J.; Peeters, F.M. |
Title |
MgB2 : superconductivity and pressure effects |
Type |
P1 Proceeding |
Year |
2003 |
Publication |
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Abbreviated Journal |
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Volume |
|
Issue |
|
Pages |
35-46 |
Keywords |
P1 Proceeding; Condensed Matter Theory (CMT) |
Abstract |
We present a Ginzburg-Landau theory for a two-band superconductor with emphasis on MgB2. We propose experiments which lead to identification of the possible scenarios: whether both sigma- and pi-bands superconduct or sigma-alone. According to the second scenario a microscopic theory of superconducting MgB2 is proposed based on the strongly interacting or-electrons and non-correlated pi-electrons of boron ions. The kinematic and Coulomb interactions of sigma-electrons provide the superconducting state with an anisotropic gap of s(*)-wave symmetry. The critical temperature T-c has a non-monotonic dependence on the distance r between the centers of gravity of sigma- and pi-bands. The position of MgB2 on a bell-shaped curve T-c (r) is identified in the overdoped region. The derived superconducting density of electronic states is in agreement with available experimental and theoretical data. It is argued that the effects of pressure are crucial to identify the microscopic origin of superconductivity in MgB2. Possibilities for increase of T, are discussed. |
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 |
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Publication Date |
0000-00-00 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
106 |
Series Issue |
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Edition |
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ISSN |
1-4020-1372-8 |
ISBN |
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Additional Links |
UA library record; WoS full record; |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:94869 |
Serial |
2020 |
Permanent link to this record |
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Author |
Piacente, G.; Schweigert, I.V.; Betouras, J.J.; Peeters, F.M. |
Title |
Generic properties of a quasi-one-dimensional classical Wigner crystal |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
69 |
Issue |
|
Pages |
045324,1-17 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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 |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000189075200069 |
Publication Date |
2004-01-30 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
148 |
Open Access |
|
Notes |
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Approved |
Most recent IF: 3.836; 2004 IF: 3.075 |
Call Number |
UA @ lucian @ c:irua:69380 |
Serial |
1327 |
Permanent link to this record |
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|
Author |
Betouras, J.J.; Ivanov, V.A.; Peeters, F.M. |
Title |
Ginzburg-Landau theory and effects of pressure on a two-band superconductor : application to MgB2 |
Type |
A1 Journal article |
Year |
2003 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
Volume |
31 |
Issue |
3 |
Pages |
349-354 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We present a model of pressure effects of a two-band superconductor based on a Ginzburg-Landau free energy with two order parameters. The parameters of the theory are pressure as well as temperature dependent. New pressure effects emerge as a result of the competition between the two bands. The theory then is applied to MgB2. We identify two possible scenaria regarding the fate of the two Q subbands under pressure, depending on whether or not both subbands are above the Fermi energy at ambient pressure. The splitting of the two subbands is probably caused by the E-2g, distortion. If only one subband is above the Fermi energy at ambient pressure (scenario I), application of pressure diminishes the splitting and it is possible that the lower subband participates in the superconductivity. The corresponding crossover pressure and Gruneisen parameter are estimated. In the second scenario both bands start above the Fermi energy and they move below it, either by pressure or via the substitution of Mg by Al. In both scenaria, the possibility of electronical topological transition is emphasized. Experimental signatures of both scenaria are presented and existing experiments are discussed in the light of the different physical pictures. |
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 |
000181614300008 |
Publication Date |
2004-03-20 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6028;1434-6036; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.461 |
Times cited |
10 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.461; 2003 IF: 1.457 |
Call Number |
UA @ lucian @ c:irua:94859 |
Serial |
1343 |
Permanent link to this record |
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Author |
Piacente, G.; Peeters, F.M.; Betouras, J.J. |
Title |
Normal modes of a quasi-one-dimensional multichain complex plasma |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics |
Abbreviated Journal |
Phys Rev E |
Volume |
70 |
Issue |
3Part 2 |
Pages |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We studied equally charged particles, suspended in a complex plasma, which move in a plane and interact with a screened Coulomb potential (Yukawa type) and with an additional external confining parabolic potential in one direction, which makes the system quasi-one-dimensional (Q1D). The normal modes of the system are studied in the presence of dissipation. We also investigated how a perpendicular magnetic field couples the phonon modes with each other. Two different ways of exciting the normal modes are discussed: (1) a uniform excitation of the Q1D lattice, and (2) a local forced excitation of the system in which one particle is driven by, e.g., a laser. Our results are in very good agreement with recent experimental findings on a finite single chain system [Liu , Phys. Rev. Lett. 91, 255003 (2003)]. Predictions are made for the normal modes of multichain structures in the presence of damping. |
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 |
000224302300081 |
Publication Date |
2004-09-21 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1539-3755;1550-2376; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.366 |
Times cited |
18 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.366; 2004 IF: NA |
Call Number |
UA @ lucian @ c:irua:69417 |
Serial |
2369 |
Permanent link to this record |
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Author |
Piacente, G.; Schweigert, I.V.; Betouras, J.J.; Peeters, F.M. |
Title |
Structural properties and melting of a quasi-one dimensional classical Wigner crystal |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
Volume |
128 |
Issue |
2-3 |
Pages |
57-61 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The structural and melting properties of a quasi-one dimensional system of charged particles, interacting through a screened Coulomb potential are investigated. Depending on the density and the screening length, the system crystallizes in different lattice structures. The structural phase transitions between them are of first or second order. The melting of the system is studied through Monte Carlo simulations and reentrant behavior as a function of density is observed as well as evidence of anisotropic melting. (C) 2003 Published by Elsevier Ltd. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000185533100004 |
Publication Date |
2003-08-12 |
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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 |
0038-1098; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.554 |
Times cited |
9 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 1.554; 2003 IF: 1.602 |
Call Number |
UA @ lucian @ c:irua:102790 |
Serial |
3253 |
Permanent link to this record |