Flux quantization

Flux quantization is a quantum phenomenon in which the magnetic field is quantized in the unit of $h/2e$, also known variously as flux quanta, fluxoids, vortices or fluxons.

Flux quantization occurs in Type II superconductors subjected to a magnetic field. Below a critical field H_c1, all magnetic flux is expulsed according to the Meissner effect and perfect diamagnetism is observed, exactly as in a Type I superconductor. Up to a second critical field value, H_c2, flux penetrates in discrete units while the bulk of the material remains superconducting. Both critical fields are temperature dependent, and tabulated values are the zero-temperature extrapolation unless otherwise noted.

See also

• Flux pinning
• Magnetic flux quantum