相关论文: Do columnar defects produce bulk pinning?
Extensive work has shown that irradiation with 0.8 GeV protons can produce randomly oriented columnar defects (CD's) in a large number of HTS materials, specifically those cuprates containing Hg, Tl, Pb, Bi, and similar heavy elements.…
This is an analytical study of pinning and spontaneous vortex phase is a system consisting of a superconducting thin film pierced by a long ferromagnetic columnar defect of finite radius $R$. The magnetic fields, screening currents, energy…
We explore in detail the angular dependent vortex dynamics in type II superconductors with aligned columnar defects introduced by irradiation with very energetic heavy-ions. We use dc magnetization measurements deep in the vortex solid…
We study the effect of a single columnar pin on a $(1+1)$ dimensional array of vortex lines in planar type II superconductors in the presence of point disorder. In large samples, the pinning is most effective right at the temperature of the…
Type II superconductors exhibit a fascinating phenomenology that is determined by the dynamical properties of the vortex matter hosted by the material. A crucial element in this phenomenology is vortex pinning by material defects, e.g.,…
To better understand vortex pinning in thin superconducting slabs, we study the interaction of a single fluctuating vortex filament with a curved line defect in (1+1) dimensions. This problem is also relevant to the interaction of scratches…
We have measured an angle-dependent contribution to the equilibrium magnetization of a YBa_2Cu_3O_{7-d} single crystal with columnar defects created by 5.8GeV Pb ions. This contribution manifests itself as a jump in the equilibrium torque…
The dynamics of quantized magnetic vortices and their pinning by materials defects determine electromagnetic properties of superconductors, particularly their ability to carry non-dissipative currents. Despite recent advances in the…
The pinning of quantized flux lines, or vortices, in the mixed state is used to quantify the effect of impurities in iron-based superconductors (IBS). Disorder at two length scales is relevant in these materials. Strong flux pinning…
The finite temperature dynamical phases of vortices in films driven by a uniform force and interacting with the periodic pinning potential of a square lattice of columnar defects are investigated by Langevin dynamics simulations of a London…
We present the transport studies of field variation of the pinning force for the flux motion across the twin boundaries in YBaCuO single crystals. It is found that the depinning current J_c decreases with an increase in the magnetic field…
The angular dependence of magnetic-field commensurability effects in thin films of the cuprate high-critical-temperature superconductor YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ (YBCO) with an artificial pinning landscape is investigated. Columns of…
We observe single vortices as they penetrate the edge of a superconductor using a high-sensitivity magneto-optical microscope. The vortices leap across a gap near the edge, a distance that decreases with increasing applied field and sample…
Superconductors often contain quantized microscopic whirlpools of electrons, called vortices, that can be modeled as one-dimensional elastic objects. Vortices are a diverse playground for condensed matter because of the interplay between…
We present a comparative study of the angular dependent critical current density in YBa2Cu3O7 films deposited on IBAD MgO and on single crystal MgO and SrTiO3 substrates. We identify three angular regimes where pinning is dominated by…
We present a detailed study on the behaviour of vortex cores in Bi_2Sr_2CaCu_2O_{8+\delta} using scanning tunneling spectroscopy. The very irregular distribution and shape of the vortex cores imply a strong pinning of the vortices by…
Superconductors can support large dissipation-free electrical currents only if vortex lines are effectively immobilized by material defects. Macroscopic critical currents depend on elemental interactions of vortices with individual pinning…
We investigate the scaling properties of single flux lines in a random pinning landscape consisting of splayed columnar defects. Such correlated defects can be injected into Type II superconductors by inducing nuclear fission or via direct…
We analyze the angular dependence of the irreversible magnetization of YBa$_2$Cu$_3$O$_7$ crystals with columnar defects inclined from the c-axis. At high fields a sharp maximum centered at the tracks' direction is observed. At low fields…
It is shown that the large effect of heavy ion-irradiation on the thermodynamical properties of the anisotropic superconductor YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ extends well into the superconducting fluctuation regime. The presence of the…