Fluxon

A fluxon is a quantum of electromagnetic flux, and may have one of several meanings:

Electromagnetic Behavior

In theoretical physics, fluxons are the constituent particles of electric and magnetic flux. Fluxons are particles similar to mesons in their manifestation. They form flux and flow in the direction of flux.

Fluxons exist in two states; electric fluxons and magnetic fluxons. The electric fluxons have a positive spin of +½ and the magnetic fluxons have a negative spin of -½. The fluxons exert force on their surroundings depending on their spin. The force exerted by fluxons is determined by Coulomb's law and Biot-Savart Law. The density of fluxons in particular region in space is directly proportional to the electric or magnetic flux density in that region.

Superconductivity

In the context of superconductivity, a fluxon (aka Abrikosov vortex) is a small whisker of normal phase surrounded by superconducting phase. Supercurrents circulate around its center. The magnetic field through such a whisker and its neighborhood, which has size of the order of London penetration depth $\lambda _{L}$ ($\sim 100$ nm), is quantized because of the phase properties of the magnetic vector potential in quantum electrodynamics.

In the context of long Josephson junctions, a fluxon (aka Josephson vortex) is made of circulating supercurrents and has no normal core. Supercurrents circulate just around mathematical center of a fluxon. Again, the magnetic flux created by circulating supercurrents is equal to a magnetic flux quantum $\Phi _{0}$.

Magnetohydrodynamics modeling

In the context of numerical MHD modeling, a fluxon is a discretized magnetic field line, representing a finite amount of magnetic flux in a localized bundle in the model. Fluxon models are explicitly designed to preserve the topology of the magnetic field, overcoming numerical resistivity effects in Eulerian models.

See also

FLUX a fluxon-based MHD simulator