We analyze numerically the process of dynamical generation of spatially localized vortices in Bose-Einstein condensates BEC’s with repulsive atomic interactions confined by two-dimensional optical lattices. Akin to bright solitons in a repulsive condensate, these nonlinear localized states exist only within the gaps of the matter-wave band-gap spectrum imposed by the periodicity of the lattice ...

The endwalls in a Taylor–Couette cell introduce adjacent boundary layers that interact with the centrifugal instability. We investigate the interaction between the endwall Ekman layers and the Taylor vortices near transition from nonvortical to vortical flow via direct numerical simulation using a spectral method. We consider a radius ratio of h50.75 in a short annulus having a length-to-gap ra...

Lattice calculations performed in Abelian gauges give strong evidence that confinement is realized as a dual Meissner effect, implying that the Yang-Mills vacuum consists of a condensate of magnetic monopoles. Alternative lattice caluclations performed in the maximum center gauge give strong support that center vortex configurations are the relevant infrared degrees of freedom responsible for c...

Magnetic vortices have generated intense interest in recent years due to their unique reversal mechanisms, fascinating topological properties, and exciting potential applications. In addition, the exchange coupling of magnetic vortices to antiferromagnets has also been shown to lead to a range of novel phenomena and functionalities. Here we report a new magnetization reversal mode of magnetic v...

Vortices forming near the slag-steel interface in the mold can entrap inclusions and cause defects in continuous casting of steel slabs. Lab experiments employing a 1/3 rd scale water model were performed to quantify the effects of stopper rod asymmetry on vortex formation. Three stopperrod placements (aligned, front-misaligned and left-misaligned) were considered. Vortex formation was visualiz...

We consider the local convective and absolute instabilities of the boundary layer on a rotating sphere located in a uniform axial flow, extending our previous work, which considered still outer fluid. Axial flow is seen to stabilise the convective instabilities, and our predicted onset of the spiral vortices is in good agreement with existing experimental data. The vortex angle is found to incr...

We study the dynamics of Josephson junction arrays with posi-tional disorder and driven by an external current. We consider weak magnetic fields, corresponding to a frustration f = n + 1/25 with n integer. We find that above the critical current i c there is a plastic flow of vortices, where most of the vortices are pinned and only a few vortices flow through channels. This dynamical regime is ...

The dynamics of vortices in a 2D Heisenberg antiferromagnet with an easy-plane anisotropy is studied numerically within the discrete spin model as well as analytically within a continuum approximation based on a suitable extension of the relativistic nonlinear σ model. We find that two like vortices scatter at 90 • during a head-on collision, whereas a vortex-antivortex pair is annihilated into...

Electric and magnetic fields created by moving uniform lattice of Josephson vortices in the magnetic field parallel to the layers are calculated in the frame of exactly solvable model. At large velocities of the vortex lattice the plasma oscillations of superconducting electrons are excited by vortex motion, this results in interference features in I-V curves at low temperatures. The spectrum o...