How is liquid nitrogen involved in quantum levitation

? An how (basically) does quantum levitation work. Thanks

I assume that you are referring to that trick where a small cube shaped magnet is suspended over an object and the magnet rolls continuously as the polarity of the underlying object switches

The conducting object is usually a disk of rare earth oxides
it is placed in a dish with liquid nitrogen bathing it
at this low temp the disk becomes super-conductive
so
when the magnet is brought near to the disk an electric current is induced in the disk such that the magnetic field of the disk repels the magnet (action/reaction)
then
the magnet's opposite pole is attracted so it flips but as it does so it induces an opposite reaction current in the disk so the magnet remains repelled (levitated)

this process repeats indefinitely because there is no resistance in the disk so the current does not run down (no ohmic losses)

this trick requires a really strong magnet such as a neodymium magnet in order to induce a strong enough reaction in the disk to support the weight of the magnet