The video below is seriously impressive. It shows a cooled superconductor quantum locked in a magnetic field. This allows the superconductor to move across a constant magnetic flux without friction. I am by no means a physicist, so I do not claim to be explaining this accurately, but I’ll do my best to sound like I know what I’m talking about.
How does it work?
To start with, let’s look at the superconductor that’s being used. What you are looking at is actually a sapphire crystal that’s about 500 microns thick, with a coating of some superconductor about .5 microns thick. This is then cooled using liquid nitrogen, and this is the really important part. When the supercoductor is warm it will allow a magnetic field to penetrate it freely, but when it is cooled with the liquid nitrogen it will warp and trap the magnetic field; forming what are referred to as quantum flux tubes. Some of these tubes become “pinned” in defects in the superconductive coating. This warping and trapping of the magnetic field is what locks the superconductor in space. The superconductor is able to move without friction down the circular magnetic track because the track has been designed to have a constant magnetic flux; that is to say, that the magnetic field does not vary to an important degree here across all of the magnets.
Check out this video below and the others for more eye candy, and for a much more in-depth explanation of this from people who truly know what they’re talking about, I encourage you to read this.