Abstract
In this article, the mechanism of stable levitation by bulk high-temperature superconductors is presented. Superconductor levitation is fascinating and thus displayed in various demonstrations. In general, superconductor levitation is explained in terms of the Meissner effect, which is not applicable in the case of levitating a permanent magnet by Y-Ba-Cu-O cooled with liquid nitrogen. For stable levitation in free space, the restoring forces must act on the levitated object in three rectangular directions, which cannot be fulfilled by simple diamagnetic levitation like that found with the Meissner effect. A pinning effect that fixes quantized fluxoids is the source of such restoring forces, and therefore, superconductor levitation is stabilized by flux pinning.
