# Fluxon

In physics, a **fluxon** is a quantum of electromagnetic flux. The term may have any of several related meanings.

## Superconductivity[edit]

In the context of superconductivity, in type II superconductors fluxons (also known as Abrikosov vortices) can form when the applied field lies between and . The fluxon is a small whisker of normal phase surrounded by superconducting phase, and Supercurrents circulate around the normal core. The magnetic field through such a whisker and its neighborhood, which has size of the order of London penetration depth (~100 nm), is quantized because of the phase properties of the magnetic vector potential in quantum electrodynamics, see magnetic flux quantum for details.

In the context of long Superconductor-Insulator-Superconductor Josephson tunnel junctions, a **fluxon** (aka Josephson vortex) is made of circulating supercurrents and has *no* normal core in the tunneling barrier. Supercurrents circulate just around the mathematical center of a fluxon, which is situated with the (insulating) Josephson barrier. Again, the magnetic flux created by circulating supercurrents is equal to a magnetic flux quantum (or less, if the superconducting electrodes of the Josephson junction are thinner than ).

## Magnetohydrodynamics modeling[edit]

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.

## References[edit]

## External links[edit]

- FLUX, a fluxon-based MHD simulator