The Meissner Effect and Levitation

Superconductors which follow this behaviour completely are classified as Type I . The first superconductors to be discovered belong to this category. 

In order to understand how the Meissner effect leads to levitation we must recall the principles of electromagnetism. 

The opposite question of how a magnetic field generates a current in a conductor is related to the foregoing discussion and is also of some interest to us. The first observation at the beginning of the century 

In fact, many large-scale electrical generators are presently based on this principle. 

The magnetic field induced by the current cancels the magnetic field induced in the superconductor by the magnet. This is the origin of the perfect diamagnetism of Type I superconductors. 

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The Meissner Effect and Levitation. Besides the absence of electrical resistance, a superconducting material is characterized by perfect diamagnetism. The exclusion of magnetic field lines from a material when it passes from a normal state to a superconducting state is shown schematically in Figure 3. 

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