Superconductive levitation. Computer graphic illustration depicting a sample of a superconducting material levitated above a magnet. Below a certain critical field intensity, a superconductor will repel a magnetic field. Thus the superconductor sample, placed over a magnet, will 'levitate'. The height of levitation is governed by the mass of the sample and the strength of the magnetic field. The tendency for superconductors to repel a magnetic field is called the Meissner Effect.