Fluxon

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

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 $\lambda_L$ (~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 the 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