Skyrmions are like ball lightning in a quantum gas

Physicists are observed three-dimensional skyrmions as electromagnetic knots that behave like quantum ball lightning. In time that might develop into a technology of tamed ball lightning for fusion reactors.

Great Balls of Lightning - By Joe Thomissen (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Skyrmions are remarkable quasi-particles that represent topological objects in a stable configuration. And scientists have already reported about them but so far without sufficient evidence in Bose-Einstein condensates, superconductors, thin magnetic films or in chiral nematic liquid crystals. In theory, skyrmions have been predicted over 40 years ago but getting experimental proof of them proved hard.

Now scientist from the American Amherst College and the Finnish Aalto University created three-dimensional skyrmions in a quantum gas. They made electromagnetic knots in this extremely thin and cold substance that are comprised of spins of the atoms. These knots have some of the properties of the mysterious ball lightning. And some physicists think that is because ball lightning itself is knotted electrical currents.

Tying Quantum Knots - Amherst College and Aalto University - Source: Aalto University YouTube Channel

And it is exactly the existence of electromagnetic knots that might explain the surprising longevity of ball lightning. They do spring into existence only occasionally during storms but they once they do they often exist for much longer than regular lighting. And that itself would be more than enough to warrant more research but the research of skyrmions might influence fusion technology because it would be great to have plasma in the reactors as tamed ball lighting.

But how to create such skyrmions? David Hall, the research lead from Amherst College says first we need to create quantum gas – an incredibly cold substance in form of a Bose-Einstein condensate. All the atoms of such a substance are in a state of minimal energy a such a quantum gas then doesn’t behave as regular gas but as a single atom. Then it is possible to knot the spins of the atoms by sudden changes of a magnetic field. The result – a knot of spins – a skyrmion.

Sources:

• https://www.sciencedaily.com/releases/2018/03/180302144835.htm
• http://www.aalto.fi/en/current/news/2018-03-02/
• http://advances.sciencemag.org/content/4/3/eaao3820