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![(a) Magnetic decoration image [24] of the vortex matter nucleated in a field-cooling process at 20 Oe in a 50 µm diameter Bi 2 Sr 2 CaCu 2 O 8+δ disk. (b) Typical disk located on top of the 16 × 16 µm 2 Hall sensor used to measure (depicted with a dotted-white frame in real size).](profile/Yanina-Fasano/publication/267515239/figure/fig1/AS:616357724946433@1523962541092/a-Magnetic-decoration-image-24-of-the-vortex-matter-nucleated-in-a-field-cooling.png)
(a) Magnetic decoration image [24] of the vortex matter nucleated in a field-cooling process at 20 Oe in a 50 µm diameter Bi 2 Sr 2 CaCu 2 O 8+δ disk. (b) Typical disk located on top of the 16 × 16 µm 2 Hall sensor used to measure (depicted with a dotted-white frame in real size).
Source publication
![Figure 1. (a) Magnetic decoration image [24] of the vortex matter...](profile/Yanina-Fasano/publication/267515239/figure/fig1/AS:616357724946433@1523962541092/a-Magnetic-decoration-image-24-of-the-vortex-matter-nucleated-in-a-field-cooling_Q320.jpg)
We investigated configurational changes in mesoscopic vortex matter with less
than thousand vortices during flux penetration in freestanding 50 $\mu$m
diameter disks of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8 +\delta}$. High-resolution AC
and DC local magnetometry data reveal oscillations in the transmittivity echoed
in peaks in the third-harmonics magneti...
Contexts in source publication
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... studied disks fabricated from macroscopic optimally-doped Bi 2 Sr 2 CaCu 2 O 8+δ (T c = 90 K) single-crystals grown by means of the traveling-solvent floating zone technique [22]. Micron- sized disks of roughly 1 µm thickness and diameter d = 50 µm as the one shown in Fig. 1 (a) were obtained by combining optical lithography and physical ion-milling techniques [23]. The disks were mounted with micron-precision manipulators onto 2D-electron-gas Hall-sensors with active areas of 16 × 16 µm 2 and glued with Apiezon N grease, see Fig. 1 ...
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... sized disks of roughly 1 µm thickness and diameter d = 50 µm as the one shown in Fig. 1 (a) were obtained by combining optical lithography and physical ion-milling techniques [23]. The disks were mounted with micron-precision manipulators onto 2D-electron-gas Hall-sensors with active areas of 16 × 16 µm 2 and glued with Apiezon N grease, see Fig. 1 (b). ...
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... modulus of the third harmonic signal is similarly converted to the magnitude | T h3 | that has a non-negligible value for non-linear magnetic response at H < H irr , the irreversibility field [26]. Figure 1 (a) shows a zoom-in of a magnetic decoration image revealing the vortex arrangement in the disks for a field-cooling experiment at 20 Oe. At the edge of the sample vortices arrange in a circular-shaped shell mimicking the disk geometry. ...
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... 85.3 K∼ T FOT for the 50 µm disks [11].black For the flux-penetration at fixed temperature experiments we discuss from now on, vortices enter into the sample on increasing field above the first-penetration field, B p (T ). In this experiment, a snapshot of flux-penetration would reveal a vortex arrangement certainly different to the one shown in Fig. 1 (a), with an induction gradient towards the sample center. However, Fig. 1 (a) suggest that in flux-penetration experiments vortices will enter into the sample in circular-shaped shells. The entrance of these shells can be continuous or discretized, namely vortices gradually enter one by one, or a circle of vortices suddenly jump into the ...
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... this experiment, a snapshot of flux-penetration would reveal a vortex arrangement certainly different to the one shown in Fig. 1 (a), with an induction gradient towards the sample center. However, Fig. 1 (a) suggest that in flux-penetration experiments vortices will enter into the sample in circular-shaped shells. The entrance of these shells can be continuous or discretized, namely vortices gradually enter one by one, or a circle of vortices suddenly jump into the sample. ...
Citations
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.
We detect the persistence of the solidification and order-disorder first-order transition lines in the phase diagram of nanocrystalline Bi_{2}Sr_{2}CaCu_{2}O_{8} 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.
