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Author (up) Aragón Sánchez, J.; Cortés Maldonado, R.; Cejas Bolecek, N.R.; Rumi, G.; Pedrazzini, P.; Dolz, M.I.; Nieva, G.; Beek, C.J. van der; Konczykowski, M.; Dewhurst, C.D.; Cubitt, R.; Kolton, A.B.; Pautrat, A.; Fasano, Y.
Title Unveiling the vortex glass phase in the surface and volume of a type-II superconductor Type Journal Article
Year 2019 Publication Communications Physics Abbreviated Journal Commun. Phys.
Volume 2 Issue 1 Pages 143
Keywords
Abstract Order-disorder transitions between glassy phases are common in nature and yet a comprehensive survey on the entailed structural changes is challenging since the constituents are in the micro-scale. Vortex matter in type-II superconductors is a model system where some of these experimental challenges can be tackled. Samples with point disorder present a glassy transition on increasing the density of vortices. A glassy yet quasi-crystalline phase, the Bragg glass, nucleates at low densities. The vortex glass stable at high densities is expected to be disordered, however its detailed structural properties remained experimentally elusive. Here we show that the vortex glass has large crystallites with in-plane positional displacements growing algebraically and short-range orientational order. Furthermore, the vortex glass has a finite and almost constant correlation length along the direction of vortices, in sharp contrast with strong entanglement. These results are important for the understanding of disorder-driven phase transitions in glassy condensed matter.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2399-3650 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Aragón Sánchez2019 Serial 843
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Author (up) Aragón Sánchez, J.; Cortés Maldonado, R.; Dolz, M.I.; CejasBolecek, N.R.; van der Beek, C.J.; Konczykowski, M.; Fasano, Y.
Title Direct visualization of local interaction forces in Bi2Sr2CaCu2O8+δ vortex matter Type Journal Article
Year 2019 Publication Materials Today: Proceedings Abbreviated Journal XXIII Latin American Symposium on Solid State Physics (SLAFES XXIII), San Carlos de Bariloche, Argen
Volume 14 Issue Pages 34-37
Keywords Vortex matter; Pinning forces; Layered superconductors
Abstract We study the local vortex-vortex interaction force fi of the structure frozen during a field-cooling process in an electron-irradiated Bi2Sr2CaCu2O8+δ sample. We compute this magnitude from snapshots of the vortex structure obtained via magnetic decoration experiments at various fields H in the same sample. Since the observed structures correspond to the equilibrium ones frozen at T∼Tirr(H)[1], at this temperature the local modulus of fi roughly equals the local pinning force at the decorated surface of the sample. We estimate the most probable local pinning force from the mode value of the fi(r)distribution, fpm. We found that fpm grows algebraically with H and in electron-irradiated samples is 50-20% smaller than for samples with columnar defects.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2214-7853 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 852
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Author (up) Bolecek, N.R.C.; Dolz, M.I.; Pastoriza, H.; Konczykowski, M.; van der Beek, C.J.; Kolton, A.B.; Fasano, Y.
Title Excess of topological defects induced by confinement in vortex nanocrystals Type Journal Article
Year 2017 Publication Physical Review B Abbreviated Journal PRB
Volume 96 Issue 2 Pages 024507
Keywords
Abstract We directly image individual vortex positions in nanocrystals in order to unveil the structural property that contributes to the depletion of the entropy jump entailed at the first-order transition. On reducing the nanocrystal size, the density of topological defects increases near the edges over a characteristic length. Within this “healing-length” distance from the sample edge, vortex rows tend to bend, while towards the center of the sample, the positional order of the vortex structure is what is expected for the Bragg-glass phase. This suggests that the healing length may be a key quantity to model confinement effects in the first-order transition of extremely layered vortex nanocrystals.
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Corporate Author Thesis
Publisher American Physical Society Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
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Notes Approved no
Call Number BT @ hernan @ 10.1103/PhysRevB.96.024507 Serial 762
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Author (up) Cejas Bolecek, N.R.; Kolton, A.B.; Konczykowski, M.; Pastoriza, H.; Dominguez, D.; Fasano, Y.
Title Vortex matter freezing in Bi2Sr2CaCu28 samples with a very dense distribution of columnar defects Type Journal Article
Year 2016 Publication Physical Review B Abbreviated Journal Phys. Rev. B
Volume 93 Issue 5 Pages 054505
Keywords
Abstract We show that the dynamical freezing of vortex structures nucleated at diluted densities in Bi2Sr2CaCu2O8 samples with a dense distribution of columnar defects, B∼10−2BΦ with BΦ=5kG, results in configurations with liquidlike correlations. We propose a freezing model considering a relaxation dynamics dominated by double-kink excitations driven by the local stresses obtained directly from experimental images. With this model we estimate the relaxation barrier and the freezing temperature. We argue that the low-field frozen vortex structures nucleated in a dense distribution of columnar defects thus correspond to an out-of-equilibrium nonentangled liquid with strongly reduced mobility rather than to a snapshot of a metastable state with divergent activation barriers as, for instance, expected for the Bose-glass phase at equilibrium.
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Corporate Author Thesis
Publisher American Physical Society Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ 10.1103/PhysRevB.93.054505 Serial 738
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Author (up) Cejas Bolecek, N.R.; Dolz, M.I.; Kolton, A.; Pastoriza, H.; Beek, C.Jvander; Konczykowski, M.; Menghini, M.; Nieva, G.; Fasano, Y.
Title Geometrical Confinement Effects in Layered Mesoscopic Vortex Matter Type Journal Article
Year 2015 Publication Journal of Low Temperature Physics Abbreviated Journal J. Low Temp. Phys.
Volume 179 Issue 1-2 Pages 35-41
Keywords Vortex matter; Mesoscopic physics; Layered superconductors
Abstract We study the geometrical confinement effect in Bi 2 Sr 2 CaCu 2 O 8+δ mesoscopic vortex matter with edge-to-surface ratio of 7–12 %. Samples have in-plane square and circular edges, 30 μ m widths, and ∼ 2 μ m thickness. Direct vortex imaging reveals the compact planes of the structure align with the sample edge by introducing topological defects. The defect density is larger for circular than for square edges. Molecular dynamics simulations suggest that this density is not an out-of-equilibrium property but rather determined by the geometrical confinement.
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Corporate Author Thesis
Publisher Springer US Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2291 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 711
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Author (up) Dolz, M. I.; Fasano, Y.; Cejas Bolecek, N. R.; Pastoriza, H.; Mosser, V.; Li, M.; Konczykowski, M.
Title Size-Induced Depression of First-Order Transition Lines and Entropy Jump in Extremely Layered Nanocrystalline Vortex Matter Type Journal Article
Year 2015 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 115 Issue 13 Pages 137003
Keywords
Abstract We detect the persistence of the solidification and order-disorder first-order transition lines in the phase diagram of nanocrystalline Bi2Sr2CaCu2O8 vortex matter down to a system size of less than one hundred vortices. The temperature location of the vortex solidification transition line is not altered by decreasing the sample size although there is a depletion of the entropy jump at the transition with respect to macroscopic vortex matter. The solid order-disorder phase transition field moves upward on decreasing the system size due to the increase of the surface-to-volume ratio of vortices entailing a decrease on the average vortex binding energy.
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Corporate Author Thesis
Publisher American Physical Society Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ hernan @ Serial 719
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Author (up) Dolz, M.I.; Bolecek, N.R.C.; Puig, J.; Pastoriza, H.; Nieva, G.; Guimpel, J.; van der Beek, C.J.; Konczykowski, M.; Fasano, Y.
Title Enhancement of penetration field in vortex matter in mesoscopic superconductors due to Andreev bound states Type Journal Article
Year 2019 Publication Physical Review B Abbreviated Journal PRB
Volume 100 Issue 6 Pages 064508
Keywords
Abstract We study the field for the penetration of a first vortex, HP, for vortex matter nucleated in micron-sized samples with edges aligned along the nodal and antinodal directions of the d-wave superconducting order parameter of Bi2Sr2CaCu2O8−δ. Here we present evidence that the HP for vortex matter nucleated in mesoscopic samples with edges parallel to the nodal direction is larger than for the antinodal case, ∼72% at low temperatures. This finding supports the theoretical proposal that surface Andreev bound states appearing in a sample with edges parallel to the nodal direction would produce an anomalous Meissner current that increases the Bean-Livingston barrier for vortex penetration.
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Corporate Author Thesis
Publisher American Physical Society Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ 10.1103/PhysRevB.100.064508 Serial 822
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Author (up) Dolz, M.I.; Pedrazzini, P.; Pastoriza, H.; Konczykowski, M.; Fasano, Y.
Title Effect of Quenched Disorder in the Entropy-Jump at the First-Order Vortex Phase Transition of Bi{2}Sr{2}CaCu{2}O{8 + \delta } Type Journal Article
Year 2015 Publication Journal of Low Temperature Physics Abbreviated Journal J. Low Temp. Phys.
Volume 179 Issue 1-2 Pages 28-34
Keywords High Tc superconductors; First order vortex phase transition; Quenched disorder
Abstract We study the effect of quenched disorder in the thermodynamic magnitudes entailed in the first-order vortex phase transition of the extremely layered Bi 2 Sr 2 CaCu 2 O 8+δ compound. We track the temperature-evolution of the enthalpy and the entropy jump at the vortex solidification transition by means of AC local magnetic measurements. Quenched disorder is introduced to the pristine samples by means of heavy-ion irradiation with Pb and Xe producing a random columnar-track pins distribution with different densities (matching field BΦ ). In contrast with previous magneto-optical reports, we find that the first-order phase transition persists for samples with BΦ up to 100 Gauss. For very low densities of quenched disorder (pristine samples), the evolution of the thermodynamic properties can be satisfactorily explained considering a negligible effect of pinning and only electromagnetic coupling between pancake vortices lying in adjacent CuO planes. This description is not satisfactory on increasing magnitude of quenched disorder.
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Corporate Author Thesis
Publisher Springer US Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2291 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 707
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Author (up) Kes, P.H.; Pastoriza, H.; Li, T.W.; Cubitt, R.; Forgan, E.M.; Lee, S.L.; Konczykowski, M.; Khaykovich, B.; Majer, D.; Fuchs, D.T.; Zeldov, E.
Title Flux lattice melting and dimensional crossover in Bi-2212 single crystals Type Journal Article
Year 1996 Publication J. Phys. I France Abbreviated Journal
Volume 6 Issue Pages 2327-2354
Keywords
Abstract Flux lattice melting in (Bi-2212) single crystals has recently been studied by various techniques. In this contribution to the I. Schegolev Memorial Volume we review some experiments and compare their results. Muon-spin rotation and small angle neutron scattering (SANS) gave the first indications for an abrupt change of the flux lattice structure along a line in the B-T phase diagram. Experiments with Hall-sensor arrays proved that the flux line lattice experiences a first order phase transition (FOT) at this line. Measured as a function of field the resistance shows an abrupt kink at the FOT line and flux flow through narrow channels reveal a sudden drop of the shear modulus. Subsequent studies showed that the location of the FOT line in the phase diagram strongly depends on oxygen stoichiometry. For decreasing temperature the FOT line terminates at a critical point and continues into an almost field independent line which represents the location of a sharp peak in the magnetization (second peak). The second-peak line coincides with a crossover region in the low temperature range of the B-T diagram where both the muon spin rotation and SANS experiments reveal a transition from a lattice of flux lines to a lattice of pancake vortices. We compare our results with theoretical scenarios.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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Area Expedition Conference
Notes Approved no
Call Number BT @ hernan @ kes96 Serial 25
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Author (up) Puig, J.; Cejas Bolecek, N.R.; Aragón Sánchez, J.; Dolz, M.I.; Konczykowski, M.; Fasano, Y.
Title Bridge in micron-sized Bi2Sr2CaCu2O8 sample act as converging lens for vortices Type Journal Article
Year 2021 Publication Physica C: Superconductivity and its Applications Abbreviated Journal Physica C
Volume 590 Issue Pages 1353948
Keywords Vortex matterMesoscopic samplesStructural properties
Abstract We report on direct imaging of vortex matter nucleated in micron-sized BiSrCaCuO superconducting samples that incidentally present a bridge structure. We find that when nucleating vortices in a field-cooling condition the deck of the bridge acts as a converging lens for vortices. By means of Bitter decoration images allowing us to quantify the enhancement of vortex-vortex interaction energy per unit length in the deck of the bridge, we are able to estimate that the deck is thinner than m. We show that the structural properties of vortex matter nucleated in micron-sized thin samples are not significantly affected by sample-thickness variations of the order of half a micron, an important information for type-II superconductors-based mesoscopic technological devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 878
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