19 research outputs found
Single vortices observed as they enter NbSe
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 thickness. This behaviour can be explained by the combined effect of the
geometrical barrier and bulk pinning.Comment: 2 pages, 1 figure, M2S-Rio proceeding
Real time magneto-optical imaging of vortices in superconductors
We demonstrate here real-time imaging of individual vortices in a NbSe2
single crystal using polarized light microscopy. A new high-sensitivity
magneto-optical (MO) imaging system enables observation of the static vortex
lattice as well as single vortex motion at low flux densities.Comment: 3 pages, 1 figur
Turbulent relaxation in the vortex lattice
The time dependence of flux patterns of an untwinned YBa2Cu3O single crystal
showing the “meandering instability” is observed at using
magneto-optical imaging. When applying a reversed external field to a
remanent
state, along the front of penetrating antivortices, flux droplets are
formed which can separate from the flux front and move in a spiral-like
fashion. It is shown that the vortices along the flux front are in fast
motion. These observations are discussed using a newly developed theory.
Furthermore, the flux patterns are analyzed in terms of flux creep