Search results for "Vortex"
showing 4 items of 244 documents
Vortex temperature in turbulent superfluids
2008
Vortex dynamics in rotating counterflow and plane Couette and Poiseuille turbulence in superfluid Helium
2008
An equation previously proposed to describe the evolution of vortex line density in rotating counterflow turbulent tangles in superfluid helium is generalized to incorporate nonvanishing barycentric velocity and velocity gradients. Our generalization is compared with an analogous approach proposed by Lipniacki, and with experimental results by Swanson et al. in rotating counterflow, and it is used to evaluate the vortex density in plane Couette and Poiseuille flows of superfluid helium.
Hierarchies of length-scale based typology in anisotropic U(1)s-wave multiband superconductors
2019
Since Ginzburg and Landau's seminal work in 1950, superconducting states have been classified by the hierarchy of the fundamental length scales of the theory, the magnetic-field penetration lengths and coherence lengths. In the simplest single-component case they form a dimensionless ratio κ. The model was generalized by Ginzburg for anisotropic materials in 1952. In this paper we expand the above length-scale analysis to anisotropic multicomponent superconductors that can have multiple coherence lengths as well as multiple magnetic-field penetration lengths, leading to unconventional length-scale hierarchies. We demonstrate that the anisotropies in multiband superconductors lead to new reg…
Field dependence of the vortex-core sizes in dirty two-band superconductors
2019
We study the structure of Abrikosov vortices in two-band superconductors for different external magnetic fields and different parameters of the bands. The vortex core size determined by the coherence lengths are found to have qualitatively different behaviour from that determined by the quasiparticle density of states spatial variation. These different vortex core length scales coincide near the upper critical field, while the discrepancy between them becomes quite significant at lower fields. Within the diffusive approximation we demonstrate several generic regimes in the field dependence of the vortex core sizes determined by the disparity of diffusion constants in the two bands.