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We examine the stability of a pinned superfluid helium vortex line by measuring its persistence at elevated temperatures. Each vortex terminates at the surface of the container, at either a rounded bump or a conical indentation. We find…

Superconductivity · Physics 2007-05-23 P. Voll , N. apRoberts-Warren , R. J. Zieve

We present measurements on both energy loss and pinning for a vortex terminating on the curved surface of a cylindrical container. We vary surface roughness, cell diameter, fluid velocity, and temperature. Although energy loss and pinning…

Superconductivity · Physics 2015-06-11 R. J. Zieve , C. M. Frei , D. L. Wolfson

We measure the interaction of a single superfluid vortex with surface irregularities. While vortex pinning in superconductors usually becomes weaker at higher temperatures, we find the opposite behavior. The pinning steadily increases…

Superconductivity · Physics 2009-10-31 L. A. K. Donev , L. Hough , R. J. Zieve

The geometric theory of vortex tunnelling in superfluid liquids is developed. Geometry rules the tunnelling process in the approximation of an incompressible superfluid, which yields the identity of phase and configuration space in the…

Condensed Matter · Physics 2017-09-27 Uwe R. Fischer

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…

Statistical Mechanics · Physics 2009-11-11 Eleni Katifori , David R. Nelson

We calculate stable arrangements for a single superfluid vortex pinned to the wall of a stationary cylindrical container. We find that, independent of the details of the pinning site, stable vortices must subtend most of the cell…

Condensed Matter · Physics 2007-05-23 R. J. Zieve , L. A. K. Donev

Vortices in a narrow superconducting strip with a square array of pinning sites are studied. The interactions of vortices with other vortices and with external sources (applied magnetic field and transport current) are calculated via a…

Superconductivity · Physics 2009-11-07 Clécio C. de Souza Silva , Leonardo R. E. Cabral , J. Albino Aguiar

Using large-scale simulations on parallel processors, we analyze in detail the dynamical behavior of superconducting vortices undergoing avalanches. In particular, we quantify the effect of the pinning landscape on the macroscopic…

Superconductivity · Physics 2009-10-30 C. J. Olson , C. Reichhardt , Franco Nori

We have measured a precessing superfluid vortex line, stretched from a wire to the wall of a cylindrical cell. By contrast to previous experiments with a similar geometry, the motion along the wall is smooth. The key difference is probably…

Superconductivity · Physics 2009-11-07 L. Hough , L. A. K. Donev , R. J. Zieve

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…

Superconductivity · Physics 2009-11-10 A. A. F. Olsen , H. Hauglin , T. H. Johansen , P. E. Goa , D. V. Shantsev

The motion of superfluid vortices in a neutron star crust is at the heart of most theories of pulsar glitches. Pinning of vortices to ions can decouple the superfluid from the crust and create a reservoir of angular momentum. Sudden large…

Solar and Stellar Astrophysics · Physics 2016-06-15 Brynmor Haskell , Andrew Melatos

We use large-scale parallel simulations to compute the motion of superconducting magnetic vortices during avalanches triggered by small field increases. We find that experimentally observable voltage bursts correspond to pulsing vortex…

Superconductivity · Physics 2015-06-25 C. J. Olson , C. Reichhardt , J. Groth , Stuart B. Field , Franco Nori

We numerically study the spatial spreading of quantized vortex lines in low temperature liquid helium. The vortex lines, initially concentrated in a small region, diffuse into the surrounding vortex-free helium, a situation which is typical…

Fluid Dynamics · Physics 2019-06-12 Em Rickinson , Nick G. Parker , Andrew W. Baggaley , Carlo F. Barenghi

We numerically examine vortices interacting with pinning arrays where a portion of the pinning sites have been removed in order to create coexisting regions of strong and weak pinning. The region without pinning sites acts as an easy-flow…

Superconductivity · Physics 2024-04-22 C. Reichhardt , C. J. O. Reichhardt

We study trapping of a cold atom by a single vortex line in an extreme type II superconducting chip, allowing for pinning and friction. We evaluate the atom's spin flip rate and its dephasing due to the vortex fluctuations in equilibrium…

Superconductivity · Physics 2012-11-20 Amir Fruchtman , Baruch Horovitz

Vortex pinning is a crucial factor that determines the critical current of practical superconductors and enables their diverse applications. However, the underlying mechanism of vortex pinning has long been elusive, lacking a clear…

We numerically show that a vortex pinning occurs in superconducting quasicrystal without impurities and defects. This vortex pinning is intrinsic since the superconducting order parameter in quasicrystal is always inhomogeneous due to the…

Superconductivity · Physics 2022-08-23 Yuki Nagai

For thin films of superfluid adsorbed on a disordered substrate, we derive the equation of motion for a vortex in the presence of a random potential within a mean field (Hartree) description of the condensate. The compressible nature of the…

Statistical Mechanics · Physics 2009-10-31 H. H. Lee , J. M. F. Gunn

We use numerical minimization of a model free energy functional to study the effects of columnar pinning centers on the structure and thermodynamics of a system of pancake vortices in the mixed phase of highly anisotropic layered…

Superconductivity · Physics 2009-11-07 Chandan Dasgupta , Oriol T. Valls

Strong pinning of superconducting flux quanta by a square array of 1 $\mu$m-sized ferromagnetic dots in a magnetic-vortex state was visualized by low-temperature magnetic force microscopy (LT-MFM). A direct correlation of the…

Superconductivity · Physics 2010-03-18 T. Shapoval , V. Metlushko , M. Wolf , B. Holzapfel , V. Neu , L. Schultz
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