Tel Aviv University's astounding "quantum levitation" demonstration
October 23, 2011
Maglev trains have been in development since before Luke Skywalker drove his first Land Speeder but, like personal rocket packs, the idea of levitating transport is taking a while to catch on. While this "quantum levitation" demonstration shown by the superconductivity group at Tel Aviv University at the 2011 Association of Science - Technology Centers' (ASTC) annual conference in Baltimore doesn't mean we'll all be floating to work anytime soon, it does remind us of the amazing potential of this kind of technology.
Lead by Prof. Guy Deutscher, the Tel Aviv University team has been experimenting with superconductors to produce "quantum trapping" and "quantum levitation" shown in the ATSC video below.
The experiment uses a crystal sapphire wafer 500 microns wide coated in a yttrium barium copper oxide (YBCO) ceramic. This "puck" is then cooled below -185ºC (-301ºF) using liquid nitrogen at which point it becomes a superconductor, meaning it's able to conduct electricity without energy loss or resistance.
A defining characteristic of a superconductor (known as the Meissner effect) is that when subjected to a magnetic field it will try to expel a magnetic flux from its core.
As the University's Quantum Levitation website explains:
"Quantum physics tells us that the magnetic field penetrates into the superconductor in the form of discrete flux tubes. The superconductor strongly pins these tubes, causing it to float in midair. This effect is called 'quantum levitation'."
It is this process that enables the sapphire wafer to become locked in suspension above a magnetic surface and travel in mid-air in an almost perpetual motion.