| Records |
| Author |
Chen, Y.; Shanenko, A.A.; Perali, A.; Peeters, F.M. |
| Title |
Superconducting nanofilms : molecule-like pairing induced by quantum confinement |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
24 |
Issue |
18 |
Pages |
185701-185701,8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract  |
Quantum confinement of the perpendicular motion of electrons in single-crystalline metallic superconducting nanofilms splits the conduction band into a series of single-electron subbands. A distinctive feature of such a nanoscale multi-band superconductor is that the energetic position of each subband can vary significantly with changing nanofilm thickness, substrate material, protective cover and other details of the fabrication process. It can occur that the bottom of one of the available subbands is situated in the vicinity of the Fermi level. We demonstrate that the character of the superconducting pairing in such a subband changes dramatically and exhibits a clear molecule-like trend, which is very similar to the well-known crossover from the Bardeen-Cooper-Schrieffer regime to Bose-Einstein condensation (BCS-BEC) observed in trapped ultracold fermions. For Pb nanofilms with thicknesses of 4 and 5 monolayers (MLs) this will lead to a spectacular scenario: up to half of all the Cooper pairs nearly collapse, shrinking in the lateral size (parallel to the nanofilm) down to a few nanometers. As a result, the superconducting condensate will be a coherent mixture of almost molecule-like fermionic pairs with ordinary, extended Cooper pairs. |
| 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 |
|
Wos |
000303500900018 |
Publication Date |
2012-04-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
26 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). AAS thanks A Bianconi, M D Croitoru and A V Vagov for useful discussions. AAS acknowledges the hospitality and fruitful interactions with G C Strinati, P Pieri and D Neilson during his visit to the University of Camerino, supported by the School of Advanced Studies of the University of Camerino. ; |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
| Call Number |
UA @ lucian @ c:irua:98223 |
Serial |
3357 |
| Permanent link to this record |
| |
|
| |
| Author |
Tadić, M.; Peeters, F.M. |
| Title |
Exciton states and oscillator strength in two vertically coupled InP/InGaP quantum discs |
Type |
A1 Journal article |
| Year |
2004 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
16 |
Issue |
47 |
Pages |
8633-8652 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Quantum mechanical coupling and strain in two vertically arranged InP/InGaP quantum dots is studied as a function of the size of the dots and the spacer thickness. The strain distribution is determined by the continuum mechanical model, while the single-band effective-mass equation and the multiband k (.) p theory are employed to compute the conduction and valence band energy levels, respectively. The exciton states are obtained from an exact diagonalization approach, and we also compute the oscillator strength for recombination. We found that the light holes are confined by strain to the spacer, which is the reason that the hole states exhibit coupling at much larger distances as compared with the electrons. At small d, the doublet structure of the hole energy levels arises as a consequence of the relocation of the light hole from the matrix to the regions located-outside the stack, close to the dot-matrix interface. When d varies, the exciton ground state exhibits numerous anticrossings with other states, which are related to the changing spatial localization of the hole as a function of d. The oscillator strength of the exciton recombination is strongly reduced in a certain range of spacer thicknesses, which effectively turns a bright exciton state into a dark one. This effect is associated with anticrossings between exciton energy levels. |
| 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 |
000225796800016 |
Publication Date |
2004-11-13 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
13 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.649; 2004 IF: 2.049 |
| Call Number |
UA @ lucian @ c:irua:99315 |
Serial |
1116 |
| Permanent link to this record |
| |
|
| |
| Author |
Scuracchio, P.; Costamagna; Peeters, F.M.; Dobry, A. |
| Title |
Role of atomic vacancies and boundary conditions on ballistic thermal transport in graphene nanoribbons |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
90 |
Issue |
3 |
Pages |
035429 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Quantum thermal transport in armchair and zigzag graphene nanoribbons is investigated in the presence of single atomic vacancies and subject to different boundary conditions. We start with a full comparison of the phonon polarizations and energy dispersions as given by a fifth-nearest-neighbor force-constant model (5NNFCM) and by elasticity theory of continuum membranes (ETCM). For free-edge ribbons, we discuss the behavior of an additional acoustic edge-localized flexural mode, known as fourth acoustic branch (4ZA), which has a small gap when it is obtained by the 5NNFCM. Then, we show that ribbons with supported edges have a sample-size dependent energy gap in the phonon spectrum which is particularly large for in-plane modes. Irrespective to the calculation method and the boundary condition, the dependence of the energy gap for the low-energy optical phonon modes against the ribbon width W is found to be proportional to 1/W for in-plane, and 1/W-2 for out-of-plane phonon modes. Using the 5NNFCM, the ballistic thermal conductance and its contributions from every single phonon mode are then obtained by the nonequilibrium Green's function technique. We found that, while edge and central localized single atomic vacancies do not affect the low-energy transmission function of in-plane phonon modes, they reduce considerably the contributions of the flexural modes. On the other hand, in-plane modes contributions are strongly dependent on the boundary conditions and at low temperatures can be highly reduced in supported-edge samples. These findings could open a route to engineer graphene based devices where it is possible to discriminate the relative contribution of polarized phonons and to tune the thermal transport on the nanoscale. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000339443800009 |
Publication Date |
2014-07-21 |
| Series Editor |
|
Series Title |
|
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 |
20 |
Open Access |
|
| Notes |
; Discussions with S. D. Dalosto and K. H. Michel are gratefully acknowledged. This work was partially supported by PIP 11220090100392 of CONICET (Argentina) and the Flemish Science Foundation (FWO-VI). We acknowledge funding from the FWO (Belgium)-MINCyT (Argentina) collaborative research project. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
| Call Number |
UA @ lucian @ c:irua:118698 |
Serial |
2911 |
| Permanent link to this record |
| |
|
| |
| Author |
Misko, V.R.; Bothner, D.; Kemmler, M.; Kleiner, R.; Koelle, D.; Peeters, F.M.; Nori, F. |
| Title |
Enhancing the critical current in quasiperiodic pinning arrays below and above the matching magnetic flux |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
18 |
Pages |
184512-184512,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Quasiperiodic pinning arrays, as recently demonstrated theoretically and experimentally using a fivefold Penrose tiling, can lead to a significant enhancement of the critical current Ic as compared to traditional regular pinning arrays. However, while regular arrays showed only a sharp peak in Ic(Φ) at the matching flux Φ1 and quasiperiodic arrays provided a much broader maximum at Φ<Φ1, both types of pinning arrays turned out to be inefficient for fluxes larger than Φ1. We demonstrate theoretically and experimentally the enhancement of Ic(Φ) for Φ>Φ1 by using non-Penrose quasiperiodic pinning arrays. This result is based on a qualitatively different mechanism of flux pinning by quasiperiodic pinning arrays and could be potentially useful for applications in superconducting microelectronic devices operating in a broad range of magnetic fields. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000283923400006 |
Publication Date |
2010-11-08 |
| Series Editor |
|
Series Title |
|
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 |
33 |
Open Access |
|
| Notes |
; This work was supported by the “Odysseus” Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles (IAP) Programme-Belgian State-Belgian Science Policy, the FWO-Vl, and by the DFG via SFB/TRR21. V. R. M. is grateful to the FWO-Vl for the support of the research stay at the DML (ASI, RIKEN), and to F. N. for hospitality. M. K. gratefully acknowledges support from the Carl-Zeiss-Stiftung, and D. B. from the Evangelisches Studienwerk e.V. Villigst. F. N. acknowledges partial support from the Laboratory of Physical Sciences, National Security Agency, Army Research Office, DARPA, AFOSR, National Science Foundation under Grant No. 0726909, JSPS-RFBR under Contract No. 09-02-92114, Grant-in-Aid for Scientific Research (S), MEXT Kakenhi on Quantum Cybernetics, and Funding Program for Innovative R&D on S&T (FIRST). ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85800 |
Serial |
1066 |
| Permanent link to this record |
| |
|
| |
| Author |
Földi, P.; Szaszkó-Bogár, V.; Peeters, F.M. |
| Title |
High-temperature conductance of a two-dimensional superlattice controlled by spin-orbit interaction |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
11 |
Pages |
115313-115313,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Rashba-type spin-orbit interaction (SOI) controlled band structure of a two-dimensional superlattice allows for the modulation of the conductance of finite size devices by changing the strength of the SOI. We consider rectangular arrays and find that the temperature dependence of the conductance disappears for high temperatures, but the strength of the SOI still affects the conductance at these temperatures. The modulation effect can be seen even in the presence of strong dephasing, which can be important for practical applications. |
| 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 |
|
| Language |
|
Wos |
000288242800007 |
Publication Date |
2011-03-11 |
| Series Editor |
|
Series Title |
|
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 |
8 |
Open Access |
|
| Notes |
; We thank M. G. Benedict and F. Bartha for useful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and M045596 and by the “TAMOP-4.2.1/B-09/1/KONV-2010-0005 project: Creating the Center of Excellence at the University of Szeged” supported by the EU and the European Regional Development Fund. P.F. was supported by a J. Bolyai grant of the Hungarian Academy of Sciences. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:88778 |
Serial |
1466 |
| Permanent link to this record |
| |
|
| |
| Author |
Sahin, H. |
| Title |
Structural and phononic characteristics of nitrogenated holey graphene |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
92 |
Issue |
92 |
Pages |
085421 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Recent experimental studies showed that formation of a two-dimensional crystal structure of nitrogenated holey graphene (NHG) is possible. Similar to graphene, NHGs have an atomically thin and strong crystal structure. Using first-principles calculations, we investigate the structural, phononic, and thermal properties of monolayer NHG crystal. Our charge analysis reveals that the charged holey sites of NHG provide a reactive ground for further functionalization by adatoms or molecules. We also found that similar to graphene, the NHG structure has quite high-frequency phonon modes and the presence of nitrogen atoms leads to the emergence of additional vibrational modes. Our phonon analysis reveals the presence of three characteristic Raman-active modes of NHG. Furthermore, the analysis of constant-volume heat capacity showed that the NHG structure has a linear temperature dependence in the low-temperature region. The strong lattice structure and unique thermal properties of the NHG crystal structure are desirable in nanoscale device applications. |
| 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 |
000359860700007 |
Publication Date |
2015-08-19 |
| Series Editor |
|
Series Title |
|
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 |
49 |
Open Access |
|
| Notes |
; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. is supported by a FWO Pegasus Long Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
| Call Number |
UA @ lucian @ c:irua:127755 |
Serial |
4252 |
| Permanent link to this record |
| |
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| |
| Author |
Neek-Amal, M.; Covaci, L.; Peeters, F.M. |
| Title |
Nanoengineered nonuniform strain in graphene using nanopillars |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
86 |
Issue |
4 |
Pages |
041405 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Recent experiments showed that nonuniform strain can be produced by depositing graphene over pillars. We employed atomistic calculations to study the nonuniform strain and the induced pseudomagnetic field in graphene on top of nanopillars. By decreasing the distance between the nanopillars a complex distribution for the pseudomagnetic field can be generated. Furthermore, we performed tight-binding calculations of the local density of states (LDOS) by using the relaxed graphene configuration obtained from atomistic calculations. We find that the quasiparticle LDOS are strongly modified near the pillars, both at low energies showing sublattice polarization and at high energies showing shifts of the van Hove singularity. Our study shows that changing the specific pattern of the nanopillars allows us to create a desired shape of the pseudomagnetic field profile while the LDOS maps provide an input for experimental verification by scanning tunneling microscopy. |
| 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 |
|
| Language |
|
Wos |
000306313900001 |
Publication Date |
2012-07-14 |
| Series Editor |
|
Series Title |
|
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 |
51 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-V1) and the EuroGRAPHENE project CONGRAN. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| Call Number |
UA @ lucian @ c:irua:100765 |
Serial |
2255 |
| Permanent link to this record |
| |
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| |
| Author |
Zha, G.-Q.; Covaci, L.; Zhou, S.-P.; Peeters, F.M. |
| Title |
Proximity-induced pseudogap in mesoscopic superconductor/normal-metal bilayers |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
82 |
Issue |
14 |
Pages |
140502-140502,4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Recent scanning tunneling microscopy (STM) measurements of the proximity effect in Au/La2−xSrxCuO4 and La1.55Sr0.45CuO4/La2−xSrxCuO4 bilayers showed a proximity-induced pseudogap [O. Yuli, I. Asulin, Y. Kalcheim, G. Koren, and O. Millo, Phys. Rev. Lett. 103, 197003 (2009)]. We describe the proximity effect in mesoscopic superconductor/normal-metal bilayers by using the Bogoliubov-de Gennes equations for a tight-binding Hamiltonian with competing antiferromagnetic and d-wave superconductivity orders. The temperature-dependent local density of states is calculated as a function of the distance from the interface. Bound state due to both d-wave and spin-density wave gaps are formed in the normal metal for energies less than the respective gaps. If there is a mismatch between the Fermi velocities in the two layers we observe that these states will shift in energy when spin-density wave order is present, thus inducing a minigap at finite energy. We conclude that the STM measurement in the proximity structures is able to distinguish between the two scenarios proposed for the pseudogap (competing or precursor to superconductivity). |
| 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 |
000282507200002 |
Publication Date |
2010-10-05 |
| Series Editor |
|
Series Title |
|
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 |
7 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), by Belgian Science Policy (IAP), by National Natural Science Foundation of China under Grants No. 10904089 and No. 60971053, by the Research Fund of Higher Education of China under Grant No. 20093108120005, by Shanghai Leading Academic Discipline project under Grant No. S30105, by Science and Technology Committee of Shanghai Municipal under Grant No. 09JC1406000, by Shanghai Municipal Education Committee under Grants No. shu-08053 and No. 10zz63, and by Innovation Funds of Shanghai University. ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:85028 |
Serial |
2735 |
| Permanent link to this record |
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| |
| Author |
Dzhurakhalov, A.A.; Atanasov, I.; Hou, M. |
| Title |
Calculation of binary and ternary metallic immiscible clusters with icosahedral structures |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
|
Issue |
|
Pages |
115415 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Recently, core-shell Ag-Co, Ag-Cu, and “onionlike” Cu-Co equilibrium configurations were predicted in the case of isolated face centered cubic (fcc) bimetallic clusters, and three shell onionlike configurations were predicted in the case of ternary metallic clusters with spherical and truncated octahedral morphologies. In the present paper, immiscible binary CuCo and ternary AgCuCo clusters with icosahedral structures are studied as functions of their size and composition. Clusters studied are formed by 13, 55, 147, 309, and 561 atoms corresponding to the five smallest possible closed shell icosahedral structures. An embedded atom model potential is used to describe their cohesion. Equilibrium configurations are investigated by means of Metropolis Monte Carlo free energy minimization in the (NPT) canonical ensemble. Most simulations are achieved at 10 and 300 K. The effect of temperature on segregation ordering is systematically investigated. Selected cases are used to identify the effect of size and composition on melting. In contrast with fcc clusters, homogeneous onionlike configurations of binary clusters are not predicted. When it is allowed by the composition, a complete outer shell is formed by Cu in binary Cu-Co clusters and by Ag in ternary Ag-Cu-Co clusters. Depending on temperature, Co may precipitate into decahedral groups under the Cu vertices of the icosahedra in binary clusters, while the Co-Cu configuration in ternary clusters drastically depends on the Ag coating. Despite the multicomponent character of the clusters and the immiscibility of the species forming them, for most compositions and sizes, equilibrium structures remain close to perfectly icosahedral at 10 K as well as at 300 K. |
| 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 |
000254542800167 |
Publication Date |
2008-03-11 |
| Series Editor |
|
Series Title |
|
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 |
11 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2008 IF: 3.322 |
| Call Number |
UA @ lucian @ c:irua:104033 |
Serial |
4517 |
| Permanent link to this record |
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| |
| Author |
Horzum, S.; Çakir, D.; Suh, J.; Tongay, S.; Huang, Y.-S.; Ho, C.-H.; Wu, J.; Sahin, H.; Peeters, F.M. |
| Title |
Formation and stability of point defects in monolayer rhenium disulfide |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
89 |
Issue |
15 |
Pages |
155433 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Recently, rhenium disulfide (ReS2) monolayers were experimentally extracted by conventional mechanical exfoliation technique from as-grown ReS2 crystals. Unlike the well-known members of transition metal dichalcogenides (TMDs), ReS2 crystallizes in a stable distorted-1T structure and lacks an indirect to direct gap crossover. Here we present an experimental and theoretical study of the formation, energetics, and stability of the most prominent lattice defects in monolayer ReS2. Experimentally, irradiation with 3-MeV He+2 ions was used to break the strong covalent bonds in ReS2 flakes. Photoluminescence measurements showed that the luminescence from monolayers is mostly unchanged after highly energetic a particle irradiation. In order to understand the energetics of possible vacancies in ReS2 we performed systematic first-principles calculations. Our calculations revealed that the formation of a single sulfur vacancy has the lowest formation energy in both Re and S rich conditions and a random distribution of such defects are energetically more preferable. Sulfur point defects do not result in any spin polarization whereas the creation of Re-containing point defects induce magnetization with a net magnetic moment of 1-3 mu B. Experimentally observed easy formation of sulfur vacancies is in good agreement with first-principles calculations. |
| 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 |
000337301200009 |
Publication Date |
2014-04-28 |
| Series Editor |
|
Series Title |
|
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 |
130 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the bilateral project FWO-TUBITAK, and the Methusalem Foundation of the Flemish government. Computational resources were provided by TUBITAK ULAK-BIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H. S. was supported by a FWO Pegasus Long Marie Curie Fellowship. D. C. was supported by a FWO Pegasus-short Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
| Call Number |
UA @ lucian @ c:irua:118410 |
Serial |
1250 |
| Permanent link to this record |
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| |
| Author |
Wang, J.; Shin, Y.; Gauquelin, N.; Yang, Y.; Lee, C.; Jannis, D.; Verbeeck, J.; Rondinelli, J.M.; May, S.J. |
| Title |
Physical properties of epitaxial SrMnO2.5−δFγoxyfluoride films |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
31 |
Issue |
36 |
Pages |
365602 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Recently, topotactic fluorination has become an alternative way of doping epitaxial perovskite oxides through anion substitution to engineer their electronic properties instead of the more commonly used cation substitution. In this work, epitaxial oxyfluoride SrMnO2.5−δ F γ films were synthesized via topotactic fluorination of SrMnO2.5 films using polytetrafluoroethylene as the fluorine source. Oxidized SrMnO3 films were also prepared for comparison with the fluorinated samples. The F content, probed by x-ray photoemission spectroscopy, was systematically controlled by adjusting fluorination conditions. Electronic transport measurements reveal that increased F content (up to γ = 0.14) systematically increases the electrical resistivity, despite the nominal electron-doping induced by F substitution for O in these films. In contrast, oxidized SrMnO3 exhibits a decreased resistivity and conduction activation energy. A blue-shift of optical absorption features occurs with increasing F content. Density functional theory calculations indicate that F acts as a scattering center for electronic transport, controls the observed weak ferromagnetic behavior of the films, and reduces the inter-band optical transitions in the manganite films. These results stand in contrast to bulk electron-doped La1−x Ce x MnO3, illustrating how aliovalent anionic substitutions can yield physical behavior distinct from A-site substituted perovskites with the same nominal B-site oxidation states. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000472232000002 |
Publication Date |
2019-09-11 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
5 |
Open Access |
|
| Notes |
Work at Drexel was supported by the National Science Foundation (NSF), grant number CMMI-1562223. Thin film synthesis utilized deposition instrumentation acquired through an Army Research Office DURIP grant (W911NF-14-1-0493). Y.S and J.M.R. were supported by NSF (Grant No. DMR-1454688). Calculations were performed using the QUEST HPC Facility at Northwestern, the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by NSF Grant No. ACI-1053575, and the Center for Nanoscale Materials (Carbon Cluster). Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. J.V. and N. G. acknowledge funding from a GOA project “Solarpaint” of the University of Antwerp. D.J. acknowledges funding from FWO project G093417N from the Flemish fund for scientific research. |
Approved |
Most recent IF: 2.649 |
| Call Number |
EMAT @ emat @UA @ admin @ c:irua:161174 |
Serial |
5293 |
| Permanent link to this record |
| |
|
| |
| Author |
Simoen, E.; Loo, R.; Claeys, C.; de Gryse, O.; Clauws, P.; van Landuyt, J.; Lebedev, O. |
| Title |
Optical spectroscopy of oxygen precipitates in heavily doped p-type silicon |
Type |
A1 Journal article |
| Year |
2002 |
Publication |
Journal of physics : condensed matter
T2 – Conference on Extended Defects in Semiconductors (EDS 2002), JUN 01-06, 2002, BOLOGNA, ITALY |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
14 |
Issue |
48 |
Pages |
13185-13193 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Results are presented on the photoluminescence (PL) characterization of heavily doped p(+) Czochralski silicon, which has been subjected to a two-step, oxygen precipitation heat treatment. It will be shown that the presence of oxygen precipitates gives rise to the D1, D2 and D5 lines, where the energy of the D1 line shifts to lower values for a stronger degree of precipitation. The occurrence of these PL features is also a function of the boron concentration in the p(+) material. The PL results are compared with Fourier transform infrared absorption data and with transmission electron microscope, results. From this, it is concluded that PL has a good potential for use in the assessment of oxygen precipitation in heavily doped silicon. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
London |
Editor |
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| Language |
|
Wos |
000180091100068 |
Publication Date |
2002-11-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
3 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.649; 2002 IF: 1.775 |
| Call Number |
UA @ lucian @ c:irua:103326 |
Serial |
2477 |
| Permanent link to this record |
| |
|
| |
| Author |
Mishra, R.S.K.; Pandey, D.; Lemmens, H.; Van Tendeloo, G. |
| Title |
Evidence for another low-temperature phase transition in tetragonal Pb(ZrxTi1-x)O3 (x=0.515,0.520) |
Type |
A1 Journal article |
| Year |
2001 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
64 |
Issue |
5 |
Pages |
054104 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Results of dielectric and resonance frequency (f(r)) measurements below room temperature are presented for Pb(ZrxTi1-x)O-3, x = 0.515 and 0.520. It is shown that the temperature coefficient of f(r) changes sign from negative to positive around 210 and 265 K for x = 0.520 and 200 and 260 K for x = 0.515. Anomalies in the real part of the dielectric constant (epsilon') are observed around the same temperatures at which the temperature coefficient of f(r) changes sign because of the electrostrictive coupling between the elastic and dielectric responses. Low-temperature powder x-ray-diffraction (XRD) data, however, reveal only one transition from the tetragonal to monoclinic phase similar to that reported by Noheda et al. [Phys. Rev. B, 61, 8687 (2000)]. Electron-diffraction data, on the other hand, reveal yet another structural transition at lower temperatures corresponding to the second anomaly in the epsilon' vs T and f(r) vs T curves. This second transition is shown to be a cell-doubling transition not observed by Noheda et al. in their XRD studies. The observation of superlattice reflections raises doubts about the correctness of the Cm space group proposed by Noheda et al. for the monoclinic phase of Pb(ZrxTi(1-x))O-3 below the second transition temperature. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000170267000028 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2001 IF: NA |
| Call Number |
UA @ lucian @ c:irua:103407 |
Serial |
1093 |
| Permanent link to this record |
| |
|
| |
| Author |
Pogosov, W.V.; Lin, N.; Misko, V.R. |
| Title |
Electron-hole symmetry and solutions of Richardson pairing model |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
| Volume |
86 |
Issue |
5 |
Pages |
235-236 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Richardson approach provides an exact solution of the pairing Hamiltonian. This Hamiltonian is characterized by the electron-hole pairing symmetry, which is however hidden in Richardson equations. By analyzing this symmetry and using an additional conjecture, fulfilled in solvable limits, we suggest a simple expression of the ground state energy for an equally-spaced energy-level model, which is applicable along the whole crossover from the superconducting state to the pairing fluctuation regime. Solving Richardson equations numerically, we demonstrate a good accuracy of our expression. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Berlin |
Editor |
|
| Language |
|
Wos |
000320286200044 |
Publication Date |
2013-05-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
6 |
Open Access |
|
| Notes |
; This work was supported by the “Odysseus” Program of the Flemish Government and the Flemish Science Foundation (FWO-Vl). W.V.P. acknowledges useful discussions with Monique Combescot and the support from the Dynasty Foundation, the RFBR (project No. 12-02-00339), and RFBR-CNRS programme (project No. 12-02-91055). ; |
Approved |
Most recent IF: 1.461; 2013 IF: 1.463 |
| Call Number |
UA @ lucian @ c:irua:109657 |
Serial |
935 |
| Permanent link to this record |
| |
|
| |
| Author |
Schoelz, J.K.; Xu, P.; Meunier, V.; Kumar, P.; Neek-Amal, M.; Thibado, P.M.; Peeters, F.M. |
| Title |
Graphene ripples as a realization of a two-dimensional Ising model : a scanning tunneling microscope study |
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 |
045413 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Ripples in pristine freestanding graphene naturally orient themselves in an array that is alternately curved-up and curved-down; maintaining an average height of zero. Using scanning tunneling microscopy (STM) to apply a local force, the graphene sheet will reversibly rise and fall in height until the height reaches 60%-70% of its maximum at which point a sudden, permanent jump occurs. We successfully model the ripples as a spin-half Ising magnetic system, where the height of the graphene plays the role of the spin. The permanent jump in height, controlled by the tunneling current, is found to be equivalent to an antiferromagnetic-to-ferromagnetic phase transition. The thermal load underneath the STM tip alters the local tension and is identified as the responsible mechanism for the phase transition. Four universal critical exponents are measured from our STM data, and the model provides insight into the statistical role of graphene's unusual negative thermal expansion coefficient. |
| 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 |
000348762200011 |
Publication Date |
2015-01-12 |
| Series Editor |
|
Series Title |
|
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 |
21 |
Open Access |
|
| Notes |
; This work was supported in part by Office of Naval Research (USA) under Grant No. N00014-10-1-0181 and National Science Foundation (USA) under Grant No. DMR-0855358. F. M. Peeters and M. Neek-Amal were supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
| Call Number |
c:irua:123866 |
Serial |
1377 |
| Permanent link to this record |
| |
|
| |
| Author |
Xu, T.; Nys, J.-P.; Addad, A.; Lebedev, O.I.; Urbieta, A.; Salhi, B.; Berthe, M.; Grandidier, B.; Stievenard, D. |
| Title |
Faceted sidewalls of silicon nanowires: Au-induced structural reconstructions and electronic properties |
Type |
A1 Journal article |
| Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
81 |
Issue |
11 |
Pages |
115403,1-115403,10 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Si nanowires with a ⟨111⟩ orientation, synthesized by vapor-liquid-solid process with low silane partial pressure reactant and gold as the catalyst, are known to exhibit sawtooth facets containing gold adsorbates. We report herein the study of the nanowire morphology by means of transmission electron microscopy and scanning tunneling microscopy. The nanowires consist of faceted sidewalls. The number of the sidewalls changes from 12 to 6 along the growth axis, giving rise to nanowires with an irregular hexagonal cross section at their base. The sidewalls are covered with Au-rich clusters. Their facets also exhibit atomic structures that reveal the presence of gold, resulting from the diffusion of gold during the growth. Based on these observations, the tapering of the nanowire is found to be related to two contributions: the reduction in the catalyst particle size during the growth and lateral overgrowth from the direct incorporation of Si species onto the nanowire sidewalls. Because the rearrangement of atoms at surfaces and interfaces might affect the growth kinetics, the trigonal symmetry as well as the higher lateral growth rate on the widest sidewalls are explained from the existence of an interfacial atomic structure with two inequivalent parts in the unit cell. Finally, spectroscopic measurements were performed on the major facets and revealed a metallic behavior at 77 K. |
| Address |
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| Corporate Author |
|
Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000276248800116 |
Publication Date |
2010-03-03 |
| Series Editor |
|
Series Title |
|
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 |
42 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
| Call Number |
UA @ lucian @ c:irua:82273 |
Serial |
1168 |
| Permanent link to this record |
| |
|
| |
| Author |
Bakalov, P.; Esfahani, D.N.; Covaci, L.; Peeters, F.M.; Tempere, J.; Locquet, J.-P. |
| Title |
Electric-field-driven Mott metal-insulator transition in correlated thin films : an inhomogeneous dynamical mean-field theory approach |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
93 |
Issue |
93 |
Pages |
165112 |
| Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
| Abstract |
Simulations are carried out based on the dynamical mean-field theory (DMFT) in order to investigate the properties of correlated thin films for various values of the chemical potential, temperature, interaction strength, and applied transverse electric field. Application of a sufficiently strong field to a thin film at half filling leads to the appearance of conducting regions near the surfaces of the film, whereas in doped slabs the application of a field leads to a conductivity enhancement on one side of the film and a gradual transition to the insulating state on the opposite side. In addition to the inhomogeneous DMFT, a local density approximation (LDA) is considered in which the particle density n, quasiparticle residue Z, and spectral weight at the Fermi level A(ω=0) of each layer are approximated by a homogeneous bulk environment. A systematic comparison between the two approaches reveals that the less expensive LDA results are in good agreement with the DMFT approach, except close to the metal-to-insulator transition points and in the layers immediately at the film surfaces. LDA values for n are overall more reliable than those for Z and A(ω=0). The hysteretic behavior (memory effect) characteristic of the bulk doping driven Mott transition persists in the slab. |
| Address |
|
| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000373572700002 |
Publication Date |
2016-04-09 |
| Series Editor |
|
Series Title |
|
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 |
5 |
Open Access |
|
| Notes |
; This work was partially funded by the Flemish Fund for Scientific Research (FWO Belgium) under FWO Grant No. G.0520.10 and the joint FWF (Austria)-FWO Grant No. GOG6616N, and by the SITOGA FP7 project. Most of the calculations were performed on KU Leuven's ThinKing HPC cluster provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government-department EWI. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:132872 |
Serial |
4167 |
| Permanent link to this record |
| |
|
| |
| Author |
Chen, Y.; Hong-Yu, W.; Peeters, F.M.; Shanenko, A.A. |
| Title |
Quantum-size effects and thermal response of anti-Kramer-Pesch vortex core |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
27 |
Issue |
27 |
Pages |
125701 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Since the 1960's it has been well known that the basic superconductive quantities can exhibit oscillations as functions of the thickness (diameter) in superconducting nanofilms (nanowires) due to the size quantization of the electronic spectrum. However, very little is known about the effects of quantum confinement on the microscopic properties of vortices. Based on a numerical solution to the Bogoliubov-de Gennes equations, we study the quantum-size oscillations of the vortex core resulting from the sequential interchange of the Kramer-Pesch and anti-Kramer-Pesch regimes with changing nanocylinder radius. The physics behind the anti-Kramer-Pesch anomaly is displayed by utilizing a semi-analytical Anderson approximate solution. We also demonstrate that the anti-Kramer-Pesch vortex core is robust against thermal smearing and results in a distinctive two-maxima structure in the local density of states, which can be used to identify the existence of the anti-Kramer-Pesch vortex. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000351294700018 |
Publication Date |
2015-03-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
4 |
Open Access |
|
| Notes |
; This work was supported by the National Natural Science Foundation of China under Grant No. NSFC-11304134, the Flemish Science Foundation (FWO-Vl), and the Methusalem program. AAS acknowledges the support of the Brazilian agencies CNPq (grants 307552/2012-8 and 141911/2012-3) and FACEPE (APQ-0589-1.05/08). WHY acknowledges the support of Scientific Research Fund of Zhejiang Provincial Education Department (Y201120994). ; |
Approved |
Most recent IF: 2.649; 2015 IF: 2.346 |
| Call Number |
c:irua:125460 |
Serial |
2787 |
| Permanent link to this record |
| |
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| |
| Author |
Tavernier, M.B.; Anisimovas, E.; Peeters, F.M. |
| Title |
Electron-vortex interaction in a quantum dot |
Type |
A1 Journal article |
| Year |
2004 |
Publication |
International journal of modern physics: B: condensed matter physics, statistical physics, applied physics
T2 – 16th International Conference on High Magnetic Fields in Semiconductor, Physics, AUG 02-06, 2004, Florida State Univ, NHMFL, Tallahassee, FL |
Abbreviated Journal |
Int J Mod Phys B |
| Volume |
18 |
Issue |
27-29 |
Pages |
3633-3636 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Small numbers N < 5 of two-dimensional Coulomb-interacting electrons trapped in a parabolic potential placed in a perpendicular magnetic field are investigated. The reduced wave function of this system, which is obtained by fixing the positions of N-1 electrons, exhibits strong correlations between the electrons and the zeros. These zeros axe often called vortices. An exact-diagonalization scheme is used to obtain the wave functions and the results are compared with results obtained from the recently proposed rotating electron molecule (REM) theory. We find that the vortices gather around the fixed electrons and repel each other, which is to a much lesser extend so for the REM results. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Singapore |
Editor |
|
| Language |
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Wos |
000227140200035 |
Publication Date |
2005-04-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0217-9792;1793-6578; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
0.736 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 0.736; 2004 IF: 0.361 |
| Call Number |
UA @ lucian @ c:irua:102749 |
Serial |
992 |
| Permanent link to this record |
| |
|
| |
| Author |
Nowak, M.P.; Szafran, B.; Peeters, F.M. |
| Title |
Resonant harmonic generation and collective spin rotations in electrically driven quantum dots |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
86 |
Issue |
12 |
Pages |
125428 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Spin rotations induced by an ac electric field in a two-electron double quantum dot are studied by an exact numerical solution of the time-dependent Schrodinger equation in the context of recent electric-dipole spin resonance experiments on gated nanowires. We demonstrate that the splitting of the main resonance line by the spin exchange coupling is accompanied by the appearance of fractional resonances and that both these effects are triggered by interdot tunnel coupling. We find that the ac-driven system generates residual but distinct harmonics of the driving frequency, which are amplified when tuned to the main transition frequency. The mechanism is universal for electron systems in electrically driven potentials and works also in the absence of electron-electron interaction or spin-orbit coupling. |
| 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 |
|
Wos |
000308867300005 |
Publication Date |
2012-09-21 |
| Series Editor |
|
Series Title |
|
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 |
29 |
Open Access |
|
| Notes |
; This work was supported by funds of the Ministry of Science and Higher Education (MNiSW) for 2012-2013 under Project No. IP2011038671, and by PL-Grid Infrastructure. M.P.N. gratefully acknowledges support from the Foundation for Polish Science (FNP) under START and MPD program cofinanced by the EU European Regional Development Fund. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| Call Number |
UA @ lucian @ c:irua:101839 |
Serial |
2885 |
| Permanent link to this record |
| |
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| |
| Author |
Sivek, J.; Sahin, H.; Partoens, B.; Peeters, F.M. |
| Title |
Giant magnetic anisotropy in doped single layer molybdenum disulfide and fluorographene |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
| Volume |
28 |
Issue |
28 |
Pages |
195301 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Stable monolayer materials based on existing, well known and stable two-dimensional crystal fluorographene and molybdenum disulfide are predicted to exhibit a huge magnetocrystalline anisotropy when functionalized with adsorbed transition metal atoms at vacant sides. Ab initio calculations within the density-functional theory formalism were performed to investigate the adsorption of the transitional metals in a single S (or F) vacancy of monolayer molybdenum disulfide (or fluorographene). We found strong bonding of the transitional metal atoms to the vacant sites with binding energies ranging from 2.5 to 5.2 eV. Our calculations revealed that these systems with adsorbed metal atoms exhibit a magnetic anisotropy, specifically the structures including Os and Ir show a giant magnetocrystalline anisotropy energy of 31-101 meV. Our results demonstrate the possibility of obtaining stable monolayer materials with huge magnetocrystalline anisotropy based on preexisting, well known and stable two-dimensional crystals: fluorographene and molybdenum disulfide. We believe that the results obtained here are useful not only for deeper understanding of the origin of magnetocrystalline anisotropy but also for the design of monolayer optoelectronic devices with novel functionalities. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
London |
Editor |
|
| Language |
|
Wos |
000374394700007 |
Publication Date |
2016-04-13 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.649 |
Times cited |
7 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 2.649 |
| Call Number |
UA @ lucian @ c:irua:133611 |
Serial |
4185 |
| Permanent link to this record |
| |
|
| |
| Author |
Nikolaev, A.V.; Michel, K.H. |
| Title |
Microscopic theory of the rhombohedral phase and transition to the monoclinic phase of solid C70 |
Type |
A1 Journal article |
| Year |
1996 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
54 |
Issue |
18 |
Pages |
12733-12743 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Starting from a model of microscopic interactions between C-70 molecules, we have developed a theory which describes the orientational dynamics and its coupling to lattice displacements in the rhombohedral phase of C-70 fullerite. The Landau free energy is calculated. We obtain a first-order phase transition to a monoclinic structure with the space group P2(1)/m. The transition is driven by the condensation of orientational quadrupoles at the F point of the Brillouin zone of the rhombohedral lattice. We find no evidence that the monoclinic structure is connected with the freezing in of orientations around the fivefold molecular axis. We calculate the lattice strains that are associated with the transition to the monoclinic structure. The theory is compared with a range of experimental data on the phase transition. |
| 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 |
A1996VT68200028 |
Publication Date |
2002-07-27 |
| 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 |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
5 |
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ lucian @ c:irua:16357 |
Serial |
2034 |
| Permanent link to this record |
| |
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| |
| Author |
Peelaers, H.; Partoens, B.; Giantomassi, M.; Rangel, T.; Goossens, E.; Rignanese, G.-M.; Gonze, X.; Peeters, F.M. |
| Title |
Convergence of quasiparticle band structures of Si and Ge nanowires in the GW approximation and the validity of scissor shifts |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
83 |
Issue |
4 |
Pages |
045306-045306,6 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Starting from fully converged density-functional theory calculations, the quasiparticle corrections are calculated for different sized Si and Ge nanowires using the GW approximation. The effectiveness of recently developed techniques in speeding up the convergence of the quasiparticle calculations is demonstrated. The complete quasiparticle band structures are also obtained using an interpolation technique based on maximallylocalized Wannier functions. From the quasiparticle results, we assess the correctness of the commonly applied scissor-shift correction. Dispersion changes are observed, which are also reflected in changes in the effective band masses calculated taking into account quasiparticle corrections. |
| 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 |
000286771400004 |
Publication Date |
2011-01-21 |
| Series Editor |
|
Series Title |
|
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 |
18 |
Open Access |
|
| Notes |
; We are grateful to Yann Pouillon for valuable technical support with the build system of ABINIT, related to the WANNIER90 library. This work was supported by the Flemish Science Foundation (FWO-Vl) and by the Interuniversity Attraction Poles Program (P6/42)-Belgian State-Belgian Science Policy. X. G. and G.-M. R. acknowledge funding from the EU's 7th Framework Programme through the ETSF I3 e-Infrastructure project (Grant No. 211956), the Communaute francaise de Belgique through the Action de Recherche Concertee 07/12-003 “Nanosystemes hybrides metal-organiques,” and the Wallon Region Project No. 816849 “ European Theoretical Spectroscopy Facility” (WALL ETSF). M. G. acknowledges funding from the FRFC Project No. 2.4.589.09.F. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
| Call Number |
UA @ lucian @ c:irua:86905 |
Serial |
510 |
| Permanent link to this record |
| |
|
| |
| Author |
Berdiyorov, G.R.; de Romaguera, A.R.C.; Milošević, M.V.; Doria, M.M.; Covaci, L.; Peeters, F.M. |
| Title |
Dynamic and static phases of vortices under an applied drive in a superconducting stripe with an array of weak links |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
| Volume |
85 |
Issue |
4 |
Pages |
130-130,8 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Static and dynamic properties of superconducting vortices in a superconducting stripe with a periodic array of weakly-superconducting (or normal metal) regions are studied in the presence of external magnetic and electric fields. The time-dependent Ginzburg-Landau theory is used to describe the electronic transport, where the anisotropy is included through the spatially-dependent critical temperature T-c. Superconducting vortices penetrating into the weak-superconducting region with smaller T-c are more mobile than the ones in the strong superconducting regions. We observe periodic entrance and exit of vortices which reside in the weak link for some short interval. The mobility of the weakly-pinned vortices can be reduced by increasing the uniform applied magnetic field leading to distinct features in the voltage vs. magnetic field response of the 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 |
Berlin |
Editor |
|
| Language |
|
Wos |
000303545400013 |
Publication Date |
2012-04-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| 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 |
32 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Belgian Science Policy (IAP), the bilateral programme between Flanders and Brazil. G.R.B. and L.C. acknowledge individual support from FWO-Vl. A.R.de C.R. acknowledges CNPq and FACEPE for financial support. ; |
Approved |
Most recent IF: 1.461; 2012 IF: 1.282 |
| Call Number |
UA @ lucian @ c:irua:98267 |
Serial |
761 |
| Permanent link to this record |
| |
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| |
| Author |
Cantoro, M.; Klekachev, A.V.; Nourbakhsh, A.; Sorée, B.; Heyns, M.M.; de Gendt, S. |
| Title |
Long-wavelength, confined optical phonons in InAs nanowires probed by Raman spectroscopy |
Type |
A1 Journal article |
| Year |
2011 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
| Volume |
79 |
Issue |
4 |
Pages |
423-428 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Strongly confined nano-systems, such as one-dimensional nanowires, feature deviations in their structural, electronic and optical properties from the corresponding bulk. In this work, we investigate the behavior of long-wavelength, optical phonons in vertical arrays of InAs nanowires by Raman spectroscopy. We attribute the main changes in the spectral features to thermal anharmonicity, due to temperature effects, and rule out the contribution of quantum confinement and Fano resonances. We also observe the appearance of surface optical modes, whose details allow for a quantitative, independent estimation of the nanowire diameter. The results shed light onto the mechanisms of lineshape change in low-dimensional InAs nanostructures, and are useful to help tailoring their electronic and vibrational properties for novel functionalities. |
| 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 |
|
| Language |
|
Wos |
000288120600005 |
Publication Date |
2011-02-03 |
| Series Editor |
|
Series Title |
|
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; 2011 IF: 1.534 |
| Call Number |
UA @ lucian @ c:irua:89502 |
Serial |
1841 |
| Permanent link to this record |
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| |
| Author |
Rezvani, S.J.; Perali, A.; Fretto, M.; De Leo, N.; Flammia, L.; Milošević, M.; Nannarone, S.; Pinto, N. |
| Title |
Substrate-induced proximity effect in superconducting niobium nanofilms |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Condensed Matter |
Abbreviated Journal |
|
| Volume |
4 |
Issue |
1 |
Pages |
4 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Structural and superconducting properties of high-quality niobium nanofilms with different thicknesses are investigated on silicon oxide (SiO2) and sapphire substrates. The role played by the different substrates and the superconducting properties of the Nb films are discussed based on the defectivity of the films and on the presence of an interfacial oxide layer between the Nb film and the substrate. The X-ray absorption spectroscopy is employed to uncover the structure of the interfacial layer. We show that this interfacial layer leads to a strong proximity effect, especially in films deposited on a SiO2 substrate, altering the superconducting properties of the Nb films. Our results establish that the critical temperature is determined by an interplay between quantum-size effects, due to the reduction of the Nb film thicknesses, and proximity effects. The detailed investigation here provides reference characterizations and has direct and important implications for the fabrication of superconducting devices based on Nb nanofilms. |
| 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 |
000464289300001 |
Publication Date |
2018-12-31 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2410-3896 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
3 |
Open Access |
|
| Notes |
; This project was financially supported by University of Camerino, FAR project CESEMN. ; |
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:159463 |
Serial |
5233 |
| Permanent link to this record |
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| |
| Author |
Galván Moya, J.E.; Nelissen, K.; Peeters, F.M. |
| Title |
Structural transitions in vertically and horizontally coupled parabolic channels of Wigner crystals |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
86 |
Issue |
18 |
Pages |
184102-184109 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Structural phase transitions in two vertically or horizontally coupled channels of strongly interacting particles are investigated. The particles are free to move in the x direction but are confined by a parabolic potential in the y direction. They interact with each other through a screened power-law potential (r(-n)e(-r/lambda)). In vertically coupled systems, the channels are stacked above each other in the direction perpendicular to the (x, y) plane, while in horizontally coupled systems both channels are aligned in the confinement direction. Using Monte Carlo (MC) simulations we obtain the ground-state configurations and the structural transitions as a function of the linear particle density and the separation between the channels. At zero temperature, the vertically coupled system exhibits a rich phase diagram with continuous and discontinuous transitions. On the other hand, the horizontally coupled system exhibits only a very limited number of phase transitions due to its symmetry. Further, we calculated the normal modes for the Wigner crystals in both cases. From MC simulations, we found that in the case of vertically coupled systems, the zigzag transition is only possible for low densities. A Ginzburg-Landau theory for the zigzag transition is presented, which predicts correctly the behavior of this transition from which we interpret the structural phase transition of the Wigner crystal through the reduction of the Brillouin zone. |
| 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 |
000310683600002 |
Publication Date |
2012-11-05 |
| Series Editor |
|
Series Title |
|
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 |
6 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| Call Number |
UA @ lucian @ c:irua:105150 |
Serial |
3271 |
| Permanent link to this record |
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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. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
London |
Editor |
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| Language |
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Wos |
000305653100012 |
Publication Date |
2012-06-21 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
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 |
|
| 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 |
| Permanent link to this record |
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|
| |
| Author |
Saniz, R.; Partoens, B.; Peeters, F.M. |
| Title |
Green function approach to superconductivity in nanowires |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
| Volume |
85 |
Issue |
14 |
Pages |
144504-144504,7 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Superconductivity in nanowires made of weak coupling superconductor materials is investigated using a Green function approach. We show that these are multigap systems in which the ratio Delta(T)/k(B)T(c) is to a large extent similar to what is observed in some high-T-c two-gap systems, such as MgB2 and some of the Fe-based superconductors. On the other hand, because of confinement, the superfluid density has a temperature behavior of the form n(s)(T) = 1 – (T/T-c)(3) near T-c, thus deviating from the BCS behavior for bulk superconductors. |
| 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 |
000302290700006 |
Publication Date |
2012-04-03 |
| Series Editor |
|
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 |
1 |
Open Access |
|
| Notes |
; This work was supported by FWO-Vl and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
| Call Number |
UA @ lucian @ c:irua:97764 |
Serial |
1381 |
| Permanent link to this record |
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| |
| Author |
Conti, S.; Perali, A.; Peeters, F.M.; Neilson, D. |
| Title |
Effect of mismatched electron-hole effective masses on superfluidity in double layer solid-state systems |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Condensed Matter |
Abbreviated Journal |
|
| Volume |
6 |
Issue |
2 |
Pages |
14 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Superfluidity has been predicted and now observed in a number of different electron-hole double-layer semiconductor heterostructures. In some of the heterostructures, such as GaAs and Ge-Si electron-hole double quantum wells, there is a strong mismatch between the electron and hole effective masses. We systematically investigate the sensitivity to unequal masses of the superfluid properties and the self-consistent screening of the electron-hole pairing interaction. We find that the superfluid properties are insensitive to mass imbalance in the low density BEC regime of strongly-coupled boson-like electron-hole pairs. At higher densities, in the BEC-BCS crossover regime of fermionic pairs, we find that mass imbalance between electrons and holes weakens the superfluidity and expands the density range for the BEC-BCS crossover regime. This permits screening to kill the superfluid at a lower density than for equal masses. |
| 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 |
000665155800001 |
Publication Date |
2021-04-07 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2410-3896 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
1 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:179635 |
Serial |
6982 |
| Permanent link to this record |
