Flux quantization

Flux quantization is a phenomenon in superconductors where magnetic flux passing through a superconducting loop can only take on discrete, specific values rather than any arbitrary amount. Imagine magnetic flux lines as tiny, indivisible packets—like indivisible currency units—that can’t be divided further. This occurs due to the quantum properties of electrons in the superconductor, resulting in the magnetic flux being "quantized" into these fixed units. This quantization ensures the stability of superconducting states and is fundamental to understanding behaviors like superconducting quantum interference devices (SQUIDs).