How Quantum Levitation Works, and Why It's Amazing [Video]

By Wesley Fenlon

Magnetism, superconductivity and some mind-blowing physics make levitation a reality.

In the category of "science that looks like magic," quantum levitation embarrasses the likes of password-snooping accelerometer hacking. Even if you don't share Insane Clown Posse's curiosity about regular old magnets, the magnetism involved in quantum levitation will pique you curiosity because it looks totally impossible.

But it's not impossible: it's real. Quantum levitation--which can rigidly log objects in space in seeming defiance of the laws of gravity--relies on a superconductor, the Meissner effect and magnetic flex tubes. We'll get to the science in a minute. First, the results--as you'll see below, quantum levitation allows for objects to be suspended in space or moved along a magnetic track like a Maglev train.

While Maglev trains require powerful electromagnets for levitation and propulsion, the quantum levitation developed at Tel Aviv University uses simpler components. The floating disc consists of a sapphire wafer and--here's the important part--a micrometer-thin sheet of barium copper oxide. When cooled below -301 degrees Fahrenheit (-185 Celsius) the barium copper oxide layer becomes a superconductor, allowing it to conduct electricity without resistance or energy loss.

As the Meissner effect explains, superconductors will expel magnetic fields from within, meaning the magnetic field bends outwards around the puck-shaped object. But in this case, the layer of barium copper oxide is so thin that some of the magnetic field still penetrates in the form of flex tubes. That's the key to quantum levitation:

Inside each magnetic flux tube superconductivity is locally destroyed. The superconductor will try to keep the magnetic tubes pinned in weak areas (e.g. grain boundaries). Any spatial movement of the superconductor will cause the flux tubes to move. In order to prevent that the superconductor remains “trapped” in midair.

Science is always more fun in action than in theory, right? Here's the University's longer video explaining the process.