Quantum Locking; Superconductors; Lenz's Law; Meissner Effect

This video blew me away the first time I saw it. My interest in Physics just grew from there! Basically, at very low temperatures, a thin wafer coated with yttrium ceramic is superconducting. That means eddy currents are generated inside the superconductor (super eddy currents!) that instantly adjusts themselves so as to repel the magnetic flux of the permanent magnets. Since there is no resistance, there is also no loss of energy; the super eddy currents can be generated in any magnitude and direction to always repel the flux giving rise to it.

Since the wafer is so thin, magnetic flux DO penetrate the superconductor, albeit in tiny discrete quantities, trapped in flux tubes. Normally, spatial displacement of the wafer will cause the flux tubes to move and disrupt its superconductivity, so to prevent that from happening, the wafers are"locked" in whatever position they are placed in, so as to avoid moving the flux tubes! This causes the superconducting wafer to just stay in whatever position it is displaced to. It can only move left right, as the magnetic flux in these left right dimension will not cause a changing magnetic field that will invoke Lenz's Law again.

Normal thick superconductors will also levitate, but they levitate in a wobbly fashion as the eddy currents keep readjusting to repel the permanent flux by Lenz's Law. Not so for the thin superconducting wafer!

#physicstuition #quantumlocking #superconductors #lenzslaw #meissnereffect