Type-II superconductor
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A review and prospects for Nb<sub>3</sub>Sn superconductor development Open
Nb3Sn superconductors have significant applications in constructing\nhigh-field (> 10 T) magnets. This article briefly reviews development of Nb3Sn\nsuperconductor and proposes prospects for further improvement. It is shown that\nsignifica…
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Thermodynamic Parameters of Single‐ or Multi‐Band Superconductors Derived from Self‐Field Critical Currents Open
Key questions for any superconductor include: what is its maximum dissipation‐free electrical current (its ‘critical current') and can this be used to extract fundamental thermodynamic parameters? Present models focus on depinning of magne…
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Visualizing the morphology of vortex lattice domains in a bulk type-II superconductor Open
Alike materials in the solid state, the phase diagram of type-II superconductors exhibit crystalline, amorphous, liquid and spatially inhomogeneous phases. The multitude of different phases of vortex matter has thence proven to act as almo…
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Fluctuation spectroscopy: From Rayleigh-Jeans waves to Abrikosov vortex clusters Open
Superconducting (SC) fluctuations, discovered in the late 1960s, have constituted an important research area in superconductivity as they are manifest in a variety of phenomena. Indeed, the underlying physics of SC fluctuations makes it po…
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Speed limit to the Abrikosov lattice in mesoscopic superconductors Open
We study the instability of the superconducting state in a mesoscopic\ngeometry for the low pinning material Mo$_3$Ge characterized by a large\nGinzburg-Landau parameter. We observe that in the current driven switching to\nthe normal state…
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Experimental formation of a fractional vortex in a superconducting bi-layer Open
We report the experimental formation of a fractional vortex generated by using a thin superconducting bi-layer in the form of a niobium bi-layer, observed as a magnetic flux distribution image taken by a scanning superconducting quantum in…
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Strong-pinning regimes by spherical inclusions in anisotropic type-II superconductors Open
The current-carrying capacity of type-II superconductors is decisively determined by how well material defect structures can immobilize vortex lines. In order to gain deeper insights into intrinsic pinning mechanisms, we have explored the …
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Voltage-ampere characteristics of YBCO coated conductor under inhomogeneous oscillating magnetic field Open
Direct current carrying type II superconductors present a dynamic resistance when subjected to an oscillating magnetic field perpendicular to the current direction. If a superconductor is under a homogeneous field with high magnitude, the …
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Single-Crystal Growth and Extremely High <i>H</i><sub>c2</sub> of 12442-Type Fe-Based Superconductor KCa<sub>2</sub>Fe<sub>4</sub>As<sub>4</sub>F<sub>2</sub> Open
Millimeter sized single crystals of KCa_2Fe_4As_4F_2 were grown using a\nself-flux method. The chemical compositions and crystal structure were\ncharacterized carefully. Superconductivity with the critical transition T_c =\n33.5 K was conf…
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A portable magnetic field of >3 T generated by the flux jump assisted, pulsed field magnetization of bulk superconductors Open
A trapped magnetic field of greater than 3 T has been achieved in a single grain GdBa2Cu3O7-δ (GdBaCuO) bulk superconductor of diameter 30 mm by employing pulsed field magnetization. The magnet system is portable and operates at temperatur…
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Time-dependent Ginzburg-Landau treatment of rf magnetic vortices in superconductors: Vortex semiloops in a spatially nonuniform magnetic field Open
We apply time-dependent Ginzburg-Landau (TDGL) numerical simulations to study the finite frequency electrodynamics of superconductors subjected to an intense rf magnetic field. Much recent TDGL work has focused on spatially uniform externa…
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Probing the pinning landscape in type-II superconductors via Campbell penetration depth Open
Type-II superconductors owe their magnetic and transport properties to vortex pinning, the immobilization of flux quanta through material inhomogeneities or defects. Characterizing the potential energy landscape for vortices, the pinning l…
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Type-I superconductivity in KBi<sub>2</sub>single crystals Open
We report on the detailed transport, magnetic, thermodynamic properties and theoretical calculation of KBi2 single crystals in superconducting and normal states. KBi2 exhibits metallic behavior at a normal state and enters the superconduct…
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Vortex nucleation in superconductors within time-dependent Ginzburg-Landau theory in two and three dimensions: Role of surface defects and material inhomogeneities Open
We use Time-Dependent Ginzburg-Landau theory to study the nucleation of\nvortices in type II superconductors in the presence of both geometric and\nmaterial inhomogeneities. The superconducting Meissner state is meta-stable up\nto a critic…
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Critical magnetic fields in a superconductor coupled to a superfluid Open
We study a superconductor that is coupled to a superfluid via density and\nderivative couplings. Starting from a Lagrangian for two complex scalar fields,\nwe derive a temperature-dependent Ginzburg-Landau potential, which is then used\nto…
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Giant paramagnetic Meissner effect in multiband superconductors Open
Superconductors, ideally diamagnetic when in the Meissner state, can also exhibit paramagnetic behavior due to trapped magnetic flux. In the absence of pinning such paramagnetic response is weak and ceases with increasing sample thickness.…
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Influence of crystalline structure on rf dissipation in superconducting niobium Open
Bulk niobium is the material mostly used in RF superconducting cavities for\naccelerator. Predicting and reducing the surface dissipation in RF is\nmandatory, since it has a tremendous cost impact on most of the large\naccelerator projects…
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Parallel magnetic field suppresses dissipation in superconducting nanostrips Open
Significance Absolute zero resistance of superconducting materials is difficult to achieve in practice due to the motion of microscopic Abrikosov vortices, especially when external currents are applied. Even a partial resistance reduction …
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Domain formation in the type-II/1 superconductor niobium: Interplay of pinning, geometry, and attractive vortex-vortex interaction Open
Vortex attraction which can cause a bundling of vortices has been observed in a multitude of type-II superconductors. While its underlying mechanisms have been extensively studied, the morphology of the emerging vortex superstructure has o…
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Campbell Response in Type-II Superconductors under Strong Pinning Conditions Open
Measuring the ac magnetic response of a type II superconductor provides valuable information on the pinning landscape (pinscape) of the material. We use strong pinning theory to derive a microscopic expression for the Campbell length λ(C),…
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Ultradense Tailored Vortex Pinning Arrays in Superconducting YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7−δ</sub>Thin Films Created by Focused He Ion Beam Irradiation for Fluxonics Applications Open
Magnetic fields penetrate a type-II superconductor as magnetic flux quanta, called vortices. In a clean superconductor they arrange in a hexagonal lattice, while by adding periodic artificial pinning centers many other arrangements can be …
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Universal behavior of the intermediate mixed state domain formation in superconducting niobium Open
In the intermediate mixed state (IMS) of type-II/1 superconductors, vortex lattice (VL) and Meissner state domains coexist due to a partially attractive vortex interaction. Using a neutron-based multiscale approach combined with magnetizat…
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Campbell penetration in the critical state of type-II superconductors Open
The penetration of an $ac$ magnetic signal into a type II superconductor\nresiding in the Shubnikov phase depends on the pinning properties of Abrikosov\nvortices. Within a phenomenological theory, the so-called Campbell penetration\ndepth…
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Between types I and II: Intertype flux exotic states in thin superconductors Open
It is well-known that the appearance of almost-empty (shallow) conduction\nbands in solids strongly affects their superconducting properties. In a shallow\nband charge carriers are depleted and have nearly zero velocities so that the\ncros…
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Enhancing superconducting critical current by randomness Open
The key ingredient of high critical currents in a type-II superconductor is defect sites that pin vortices. Here, we demonstrate that a random pinscape, an overlooked pinning system in nanopatterned superconductors, can lead to a substanti…
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The onset of dissipation in high-temperature superconductors: Self-field experiments Open
The transport critical current, Ic, is usually defined in terms of a threshold electric field criterion, Ec, with the convention Ec = 1 μV/cm chosen somewhat arbitrarily to provide “reasonably small” electric power dissipation in practical…
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Effect of dimensionality on the vortex dynamics in a type-II superconductor Open
We explore the effects of sample dimensionality on vortex pinning in a\ntype-II, low-$T_C$, s-wave superconductor, NbN, in the presence of a\nperpendicular magnetic field, $H$. We find significant differences in the phase\ndiagrams in the …
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Flux free growth of large FeSe1/2Te1/2 superconducting single crystals by an easy high temperature melt and slow cooling method Open
We report successful growth of flux free large single crystals of superconducting FeSe1/2Te1/2 with typical dimensions of up to few cm. The AC and DC magnetic measurements revealed the superconducting transition temperature (Tc) value of a…
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Niobium in the clean limit: An intrinsic type-I superconductor Open
Niobium is one of the most researched superconductors, both theoretically and experimentally. It is enormously significant in all branches of superconducting applications, from powerful magnets to quantum computing. It is therefore imperat…
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Superconducting Phases in Neutron Star Cores Open
Using a phenomenological Ginzburg–Landau model that includes entrainment, we identify the possible ground states for the neutron and proton condensates in the core of a neutron star, as a function of magnetic field strength. Combining anal…