Records |
Author |
Ivanov, V.A.; Betouras, J.J.; Peeters, F.M. |
Title |
MgB2 : superconductivity and pressure effects |
Type |
P1 Proceeding |
Year |
2003 |
Publication |
|
Abbreviated Journal |
|
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 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
106 |
Series Issue |
|
Edition |
|
ISSN |
1-4020-1372-8 |
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:94869 |
Serial |
2020 |
Permanent link to this record |
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|
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Author |
Krstajić, P.M.; Peeters, F.M.; Ivanov, V.A.; Fleurov, V.; Kikoin, K. |
Title |
Double-exchange mechanisms for Mn-doped III-V ferromagnetic semiconductors |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
70 |
Issue |
|
Pages |
195215,1-16 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
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 |
000225477800077 |
Publication Date |
2004-11-23 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
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 |
115 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.836; 2004 IF: 3.075 |
Call Number |
UA @ lucian @ c:irua:69395 |
Serial |
754 |
Permanent link to this record |
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|
|
Author |
Shanenko, A.A.; Ivanov, V.A. |
Title |
Effects of confining interaction in meso-superconductors |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Physics letters : A |
Abbreviated Journal |
Phys Lett A |
Volume |
322 |
Issue |
5-6 |
Pages |
384-389 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
This Letter presents a generalized Ginzburg-Landau equation for the superconducting order parameter which includes the terms resulting from the confining interaction associated with the specimen boundary. While the original Ginzburg-Landau theory had been developed for a bulk superconductor, this generalization is meant for study of a meso-superconductor. (C) 2004 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000220123600018 |
Publication Date |
2004-02-05 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0375-9601; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.772 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.772; 2004 IF: 1.454 |
Call Number |
UA @ lucian @ c:irua:103244 |
Serial |
859 |
Permanent link to this record |
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Author |
Krstajic, P.M.; Ivanov, V.A.; Peeters, F.M.; Fleurov, V.; Kikoin, K. |
Title |
Ferromagnetism in Mn-doped GaAs : the kinematic exchange |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Journal of superconductivity
T2 – PASPS Conference 2002, JUL, 2002, WURZBURG, GERMANY |
Abbreviated Journal |
J Supercond |
Volume |
16 |
Issue |
1 |
Pages |
111-113 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We developed a microscopic model in order to describe the onset of ferromagnetism (FM) in GaAs:Mn. The proposed kinematic mechanism bears resemblances with the Zener exchange. The calculated Curie temperature for GaAs: Mn is in good agreement with available experimental data of the Curie temperature as a function of the manganese concentration. |
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 |
|
Wos |
000182060400027 |
Publication Date |
2003-06-06 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0896-1107; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
2 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: NA |
Call Number |
UA @ lucian @ c:irua:103314 |
Serial |
1183 |
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 |
|
Wos |
000181614300008 |
Publication Date |
2004-03-20 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1434-6028;1434-6036; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.461 |
Times cited |
10 |
Open Access |
|
Notes |
|
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 |
Fleurov, V.; Kikoin, K.; Ivanov, V.A.; Krstajic, P.M.; Peeters, F.M. |
Title |
Mechanisms of double magnetic exchange in dilute magnetic semiconductors |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Journal of magnetism and magnetic materials
T2 – International Conference on Magnetism (ICM 2003), JUL 27-AUG 01, 2003, Rome, ITALY |
Abbreviated Journal |
J Magn Magn Mater |
Volume |
272 |
Issue |
Part 3 |
Pages |
1967-1968 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A microscopic Hamiltonian for interacting manganese impurities in dilute magnetic semiconductors (DMS) is derived. It is shown that in p-type III-V DMS, the indirect exchange between Mn impurities has similarities with the Zener mechanism in transition metal oxides. Here the mobile and localized holes near the top of the valence band play the role of unoccupied p-orbitals which induce ferromagnetism. T-C estimated from the proposed kinematic exchange agrees with experiments on (Ga,Mn)As. The model is also applicable to the p-doped (Ga,Mn)P system. The magnetic ordering in n-type (Ga,Mn)N is due to exchange between the electrons localized on the levels lying deep in the forbidden energy gap. This mechanism is even closer to the original Zener mechanism. (C) 2003 Elsevier B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000222236800142 |
Publication Date |
2004-01-20 |
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 |
|
ISSN |
0304-8853; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.63 |
Times cited |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.63; 2004 IF: 1.031 |
Call Number |
UA @ lucian @ c:irua:103233 |
Serial |
1981 |
Permanent link to this record |
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Author |
Ivanov, V.A.; Krstajic, P.M.; Peeters, F.M.; Fleurov, V.; Kikoin, K. |
Title |
On the ferromagnetic exchange in Mn-doped III-V semiconductors |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Physica: B : condensed matter
T2 – 23rd International Conference on Low Temperature Physics (LT23), AUG 20-27, 2002, HIROSHIMA, JAPAN |
Abbreviated Journal |
Physica B |
Volume |
329 |
Issue |
Part 2 |
Pages |
1282-1283 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We propose a microscopic model for double exchange in GaAs:Mn, GaP:Mn which is based on the interaction between the transition metal impurities and the heavy holes of host semiconductor. The kinematic exchange is derived and the Curie temperature is calculated which agrees with recent experiments. (C) 2003 Elsevier Science B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000183802700400 |
Publication Date |
2003-02-28 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.386 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.386; 2003 IF: 0.908 |
Call Number |
UA @ lucian @ c:irua:103813 |
Serial |
2435 |
Permanent link to this record |
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|
Author |
Ivanov, V.A.; Krstajic, P.M.; Peeters, F.M.; Fleurov, V.; Kikoin, K. |
Title |
On the nature of ferromagnetism in dilute magnetic semiconductors : GaAs:Mn and GaP:Mn |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Journal of magnetism and magnetic materials
T2 – 2nd Moscow International Symposium on Magnetism (MISM 2001), JUN 20-24, 2001, MOSCOW STATE UNIV, MOSCOW, RUSSIA |
Abbreviated Journal |
J Magn Magn Mater |
Volume |
258 |
Issue |
|
Pages |
237-240 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
On the basis of a simplified Hamiltonian for transition metal impurities in diluted magnetic semiconductors (DMS), the nature of ferromagnetism in p-type III-V DMS are investigated. Ferromagnetism is governed by the Anderson-Hubbard parameter for 3d electrons of Mn2+ and their strong hybridization with the hole carriers in the semiconducting medium. The origin of ferromagnetism in these materials has similarity with the Zener mechanism. From the energetically preferable parallel orientation of Mn spins the Curie temperature is calculated for GaAs:Mn. (C) 2002 Published by Elsevier Science B.V. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000181702000062 |
Publication Date |
2003-03-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-8853; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.63 |
Times cited |
10 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.63; 2003 IF: 0.910 |
Call Number |
UA @ lucian @ c:irua:103311 |
Serial |
2442 |
Permanent link to this record |
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|
Author |
Krstajic, P.M.; Ivanov, V.A.; Peeters, F.M.; Fleurov, V.; Kikoin, K. |
Title |
On the nature of ferromagnetism in diluted magnetic semiconductors : GaAs:Mn |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Europhysics letters |
Abbreviated Journal |
Epl-Europhys Lett |
Volume |
61 |
Issue |
2 |
Pages |
235-241 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
An energy level diagram is constructed on the basis of a microscopic Hamiltonian proposed for a description of interacting manganese impurities in diluted magnetic semiconductors (DMS). It is shown that ferromagnetism in p-type III-V DMS is governed by the strong hybridization of Mn2+-electrons with the mobile holes and localized states near the top of the valence band. The Curie temperature estimated from the proposed kinematic exchange agrees with the experiments on GaAs:Mn. The model is also applicable to the GaP:Mn system. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Paris |
Editor |
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Language |
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Wos |
000180283200015 |
Publication Date |
2003-12-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0295-5075;1286-4854; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.957 |
Times cited |
38 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.957; 2003 IF: 2.075 |
Call Number |
UA @ lucian @ c:irua:103318 |
Serial |
2443 |
Permanent link to this record |
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|
Author |
Fleurov, V.; Ivanov, V.A.; Peeters, F.M.; Vagner, I.D. |
Title |
Spin-engineered quantum dots |
Type |
A1 Journal article |
Year |
2002 |
Publication |
Physica. E: Low-dimensional systems and nanostructures |
Abbreviated Journal |
Physica E |
Volume |
14 |
Issue |
4 |
Pages |
361-365 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
Abstract |
Spatially nonhomogeneously spin polarized nuclei are proposed as a new mechanism to monitor electron states in a nanostructure, or as a means to create and, if necessary, reshape such nanostructures in the course of the experiment. We found that a polarization of nuclear spins may lift the spin polarization of the electron states in a nanostructure and, if sufficiently strong, leads to a polarization of the electron spins. Polarized nuclear spins may form an energy landscape capable of binding electrons with energy up to several meV and the localization radius > 100 Angstrom. (C) 2002 Elsevier Science B.V. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
North-Holland |
Place of Publication |
Amsterdam |
Editor |
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Language |
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Wos |
000177511900003 |
Publication Date |
2002-10-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
|
ISSN |
1386-9477; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.221 |
Times cited |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.221; 2002 IF: 1.107 |
Call Number |
UA @ lucian @ c:irua:104150 |
Serial |
3088 |
Permanent link to this record |
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Author |
Ivanov, V.A.; van den Broek, M.; Peeters, F.M. |
Title |
Strongly interacting σ-electrons and MgB2 superconductivity |
Type |
A1 Journal article |
Year |
2001 |
Publication |
Solid state communications |
Abbreviated Journal |
Solid State Commun |
Volume |
120 |
Issue |
|
Pages |
53-57 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
|
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000171221900001 |
Publication Date |
2002-10-31 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0038-1098; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.554 |
Times cited |
5 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.554; 2001 IF: 1.381 |
Call Number |
UA @ lucian @ c:irua:37304 |
Serial |
3187 |
Permanent link to this record |
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Author |
Ivanov, V.A.; Misko, V.R.; Fomin, V.M.; Devreese, J.T. |
Title |
Superconductivity in mesoscopic high-Tc superconducting particles |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Solid State Communications |
Abbreviated Journal |
Solid State Commun |
Volume |
125 |
Issue |
|
Pages |
439-444 |
Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
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 |
New York, N.Y. |
Editor |
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Language |
|
Wos |
000181023700017 |
Publication Date |
2003-01-30 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0038-1098; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
1.554 |
Times cited |
3 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 1.554; 2003 IF: 1.602 |
Call Number |
UA @ lucian @ c:irua:40871 |
Serial |
3372 |
Permanent link to this record |