Magnetic Field Produces Amazing Feat of Quantum Levitation
Will children soon have hoverboards like Marty McFly in "Back to the Future?" In an amazing mating of science fiction and reality, a student from Tel Aviv University's Superconductivity Group School of Physics and Astronomy showed off a puck hovering in mid-air through the phenomenon known in physics as quantum levitation.
The video, taken at this year's Association of Science conference in Maryland, shows how the effects of quantum locking or quantum trapping can make a semiconductor float in mid-air. The student demonstrated how the super-cooled object hovered over a magnetic field even when he turned it upside down. The object even kept the same position when the student turned the track upside down.
So how exactly does it work? The quantum levitation effect can be explained by the Meissner effect, which describes how a superconducting material emits magnetic fields from its interior. If the material is thin enough the magnetic field can leave the object but only in thin amounts.
The Tel Aviv team super-cooled the disk, composed of a sapphire wafer coated with an ultrathin layer of yttrium barium copper oxide, to a temperature of negative 185 degrees Celsius. The disk is now a superconductor and strongly diamagnetic. This means that if the disk has a magnetic field applied to it, the disk will create an equally opposing magnetic field. The super-cooled disk is repelling the magnets in the device the student is holding. And there you have the science of levitation.
Can we now look forward to our own hoverboards?