Dynamics of vortex cluster crystallisation and single-vortex pinning in two-dimensional superfluids

2021 ◽  
Author(s):  
◽  
Oliver Stockdale
Keyword(s):  
Vortex Pinning ◽  
Two Dimensional ◽  
Single Vortex ◽  
Vortex Cluster

Vortex Pinning and Dynamics in HTS films: Role of Extended Linear Defects

2011 ◽  
Vol 1367 ◽  
Author(s):  
Alexander L. Kasatkin ◽  
Constantin G. Tretiatchenko ◽  
Volodymyr M. Pan
Keyword(s):  
Lorentz Force ◽  
Classical Mechanics ◽  
Vortex Pinning ◽  
Dislocation Model ◽  
Linear Defect ◽  
Single Vortex ◽  
Linear Defects ◽  
Anisotropic Superconductor ◽  
Hts Films

ABSTRACTThe model of single vortex escape from extended linear defect and subsequent vortex dynamics under the Lorentz force action in a rather thick (d > 2λ) 3D anisotropic superconductor is developed. We consider the case of parallel c-oriented linear defects as well as the case of equidistant linear row of such kind of defects, which represents the dislocation model of low-angle [001] tilt grain boundary in HTS films and bicrystals. The suggested model based on the classical mechanics approach allows to describe behavior of an elastic vortex string in the potential well of linear defect and under the action of Lorentz force on its end within the Meissner current carrying layer and to determine the depinning critical current density at low magnetic fields and temperatures.

Observation of single-vortex pinning in superfluid 4He

1998 ◽  
Vol 255 (1-4) ◽  
pp. 55-74 ◽  
Author(s):  
E. Varoquaux ◽  
O. Avenel ◽  
P. Hakonen ◽  
Yu. Mukharsky
Keyword(s):  
Vortex Pinning ◽  
Superfluid 4He ◽  
Single Vortex

scholarly journals Eigenstates of the Vorticity Operator: The Creation and Annihilation of Vortex States in Two Dimensions

1997 ◽  
Vol 11 (10) ◽  
pp. 1267-1280 ◽  
Author(s):  
A. D. Speliotopoulos
Keyword(s):  
Two Dimensions ◽  
Quantum Mechanical ◽  
Two Dimensional ◽  
Single Vortex ◽  
Creation And Annihilation Operators ◽  
Vortex States ◽  
Mechanical Description ◽  
Quantum Mechanical Description ◽  
The Creation

A quantum mechanical description of vortices in two-dimensional superfluid 4 He films is presented. Single vortex creation and annihilation operators are defined and wavefunctions for these states are explicitly constructed.

Vortex formation out of two-dimensional orifices

2010 ◽  
Vol 655 ◽  
pp. 198-216 ◽  
Author(s):  
GIANNI PEDRIZZETTI
Keyword(s):  
Shear Layer ◽  
Formation Process ◽  
Vortex Formation ◽  
Formation Time ◽  
Inviscid Limit ◽  
Small Scale ◽  
Two Dimensional ◽  
Single Vortex ◽  
Vortex Model ◽  
Vortex Pairs

The understanding of the vortex formation process is currently driving a novel attempt to evaluate the performance of fluid dynamics in biological systems. The concept of formation time, developed for axially symmetric orifices, is here studied in two-dimensional flows for the generation of vortex pairs. The early stage of the formation process is studied with the single vortex model in the inviscid limit. Within this framework, the equation can be written in a universal form in terms of the formation time. The single vortex model properly represents the initial circular spiralling vortex sheet and its acceleration for self-induced motion. Then, an analysis is performed by numerical simulation of the two-dimensional Navier–Stokes equations to cope with the spatially extended vortex structure. The results do not show the pinch-off phenomenon previously reported for vortex rings. The two-dimensional vortex pair tends to a stably growing structure such that, while it translates and extends longitudinally, it remains connected to the sharp edge by a shear layer whose velocity is always about twice that of the leading vortex. At larger values of the Reynolds number the instability of the shear layer develops small-scale vortices capable of destabilizing the coherent vortex growth. The absence of a critical formation number for two-dimensional vortex pairs suggests further considerations for the development of concepts of optimal vortex formation from orifices with variable curvature or of a tapered shape.

Two-dimensional vortex-pinning phenomena in YBa2Cu3Oy films

2008 ◽  
Vol 92 (13) ◽  
pp. 132502 ◽  
Author(s):  
S. Horii ◽  
M. Takamura ◽  
M. Mukaida ◽  
A. Ichinose ◽  
K. Yamada ◽  
...  
Keyword(s):  
Vortex Pinning ◽  
Two Dimensional

scholarly journals Symmetry and disorder of the vitreous vortex lattice in overdopedBaFe2−xCoxAs2: Indication for strong single-vortex pinning

2010 ◽  
Vol 81 (1) ◽  
Author(s):  
D. S. Inosov ◽  
T. Shapoval ◽  
V. Neu ◽  
U. Wolff ◽  
J. S. White ◽  
...  
Keyword(s):  
Vortex Lattice ◽  
Vortex Pinning ◽  
Single Vortex

On the inviscid instability of certain two-dimensional vortex-type flows

1967 ◽  
Vol 29 (4) ◽  
pp. 647-666 ◽  
Author(s):  
Alfons Michalke ◽  
Adalbert Timme
Keyword(s):  
Boundary Layer ◽  
Free Boundary ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Rotating Fluids ◽  
Single Vortex ◽  
Vortex Model ◽  
Breakdown Phenomenon ◽  
Extremum Value ◽  
Inviscid Instability

As a contribution to the breakdown phenomenon of vortices in a two-dimensional free boundary layer, this paper deals with the question whether a single cylindrical (i.e. two-dimensional) vortex can become unstable. For this reason a single vortex, as it occurs in a free boundary layer, is approximated by an axisymmetrical vortex model. The inviscid stability theory of rotating fluids is then applied to this vortex model. By general stability criteria it was found that a vortex consisting of vorticity of one sign only is stable according to the Rayleigh criterion, but, if the vorticity has an extremum value outside the axis, may become unstable with respect to cylindrical disturbances. Furthermore, stability calculations for three special types of vortex were performed. It was found that they were more unstable with respect to cylindrical disturbances than to three-dimensional ones.

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