Mysterious Loops in The Fabric of Reality: Physicists Get First Glimpse of 'Alice Rings'

[Judi Lynn]

PHYSICS
29 August 2023
ByMIKE MCRAE



(Heikka Valja/Aalto University)

Strange loops in the fabric of reality have finally been witnessed forming in a super cold gas, providing physicists with an opportunity to study the behaviors of a rather peculiar kind of one-sided magnetism.

Known as 'Alice rings' after the Alice of 'Wonderland' fame, the circular structures were observed by a collaboration between researchers in the US and Finland which already has a long list of discoveries concerning the distortions in quantum fields known as topological monopoles.

The isolated equivalent of a pole on a magnet, monopoles truly sound like something Alice would have seen in her hunt for the white rabbit. Cutting a magnet in half won't succeed in separating its north from south, but monopoles can theoretically arise in the quantum machinery that gives rise to various forces and particles.

One version of the monopole takes the form of an elementary particle, one that has defied all attempts to identify so remains, for now, purely hypothetical.

Yet monopoles can emerge in other settings. The frothing of various quantum fields can give rise to their own style of one-sided magnetism as they swirl, pulling and tugging on their surrounds to give birth to short-lived anomalies that stand out for a split moment before vanishing into the churn once more.

More:
https://www.sciencealert.com/mysterious-loops-in-the-fabric-of-reality-physicists-get-first-glimpse-of-alice-rings

[Easterncedar]

1. Fascinating!

Mind expanding. Nice way to start the day. Thanks, Judi Lynn!

[xocetaceans]

2. Here is the article behind that article...

Observation of an Alice ring in a Bose–Einstein condensate

Alina Blinova, Roberto Zamora-Zamora, Tuomas Ollikainen, Markus Kivioja, Mikko Möttönen & David S. Hall

Nature Communications volume 14, Article number: 5100 (2023)

Abstract

Monopoles and vortices are fundamental topological excitations that appear in physical systems spanning enormous scales of size and energy, from the vastness of the early universe to tiny laboratory droplets of nematic liquid crystals and ultracold gases. Although the topologies of vortices and monopoles are distinct from one another, under certain circumstances a monopole can spontaneously and continuously deform into a vortex ring with the curious property that monopoles passing through it are converted into anti-monopoles. However, the observation of such Alice rings has remained a major challenge, due to the scarcity of experimentally accessible monopoles in continuous fields. Here, we present experimental evidence of an Alice ring resulting from the decay of a topological monopole defect in a dilute gaseous 87Rb Bose–Einstein condensate. Our results, in agreement with detailed first-principles simulations, provide an unprecedented opportunity to explore the unique features of a composite excitation that combines the topological features of both a monopole and a vortex ring.

...

Blinova, A., Zamora-Zamora, R., Ollikainen, T. et al. Observation of an Alice ring in a Bose–Einstein condensate. Nat Commun 14, 5100 (2023). https://doi.org/10.1038/s41467-023-40710-2