170,224 research outputs found
Guiding-center dynamics of vortex dipoles in Bose-Einstein condensates
A quantized vortex dipole is the simplest vortex molecule, comprising two
counter-circulating vortex lines in a superfluid. Although vortex dipoles are
endemic in two-dimensional superfluids, the precise details of their dynamics
have remained largely unexplored. We present here several striking observations
of vortex dipoles in dilute-gas Bose-Einstein condensates, and develop a
vortex-particle model that generates vortex line trajectories that are in good
agreement with the experimental data. Interestingly, these diverse trajectories
exhibit essentially identical quasi-periodic behavior, in which the vortex
lines undergo stable epicyclic orbits.Comment: 4 pages, 2 figure
Evidence of Vortex Jamming in Abrikosov Vortex Flux Flow Regime
We report on dynamics of non-local Abrikosov vortex flow in mesoscopic
superconducting Nb channels. Magnetic field dependence of the non-local voltage
induced by the flux flow shows that vortices form ordered vortex chains.
Voltage asymmetry (rectification) with respect to the direction of vortex flow
is evidence that vortex jamming strongly moderates vortex dynamics in
mesoscopic geometries. The findings can be applied to superconducting devices
exploiting vortex dynamics and vortex manipulation, including superconducting
wires with engineered pinning centers.Comment: 5 pages, 3 figure
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