A time crystal to store information

E. Edwards  JQI

E. Edwards JQI

In 2012, Wilczek proposed that perhaps at the atomic level it would be possible to create a type of matter that broke time symmetry; he called it a "time crystal".

The other experiment, led by Mikhail Lukin of Harvard University, involved a less precise but more natural set-up.

We consider ourselves relatively intelligent here in JOE, but we've got to be honest, we read this a few times and we're still not 100% we fully understand it.

Why is this discovery so important?

The full peer-reviewed journal has been published today in Nature.

The researchers used a diamond filled with one million nitrogen vacancy color centers, which are spots in the diamond's carbon crystal lattice where nitrogen atoms replaced carbon atoms. Time crystals, however, move in repeating patterns in time and not space and can never reach equilibrium. Magnets have north and south poles, which means the magnetic spins of atoms within a magnet are not, as would be expected, spread in all directions but aligned in one direction or another.

Thus, it seems to be proved that the time crystals that were once considered impossible can actually exist. But such applications are still a long way off, especially since the time crystal that Zhang and collaborators produced lasted less than a millisecond.

This assymetric structure still repeats itself in space. In physics parlance, crystals are said to "break translational symmetry in space" because the atoms assemble into rigid patterns rather than being evenly spread out, as they are in a liquid or gas. This research is also detailed in Nature.

The idea kicked off a storm of interest.

This is what two new experiments appear to have achieved.

Time crystals were supposed to be physically impossible. With time crystals, the atoms prefer different states at different points in time. "It could allow you to maintain quantum purity in a big system". "The atoms move in time, but instead of doing this fluently or in a continuous manner, they move periodically". "When you release the sponge, you expect it to resume its shape".

That would be like dribbling a basketball once per second, but somehow the ball responds by bouncing once every two seconds, a speed that refuses to change even if you start dribbling a little harder. "That is what our system does", he said. Because the quantum behavior in a time crystal isn't affected by outside forces, researchers see it as a potential tool for protecting information in quantum computers.

To illustrate the weirdness of time crystals, Norman Yao of the UC Berkeley team and this current study, used the example of tapping on a bowl of Jell-O. Then, the first-ever time crystal was made just a month later in October.

Prototype quantum computers exist, but need to be heavily shielded from the slightest interference from the outside world.

"This freaky state of matter results from a complex interplay between many quantum controls at the individual atomic level", says UMD's Monroe.

Sondhi said that the work addresses some of the most fundamental questions about the nature of matter. "It is a big deal when you can give a definition of a phase of matter when the matter is not in equilibrium". A Harvard scientific team created this new element.

The research at Princeton and the Max Planck Institute was supported by the National Science Foundation (grant no. 1311781), the John Templeton Foundation, the Alexander von Humboldt Foundation and the German Science Foundation 's Gottfried Wilhelm Leibniz Prize Programme.

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