Quantum physics is full of avenues that lead to fascinating new areas of research, but one rabbit hole offers a unique perspective on a world where particles behave differently – through the proverbial looking glass.
The object, nicknamed the “Alice Ring” after Lewis Carroll’s famous Alice in Wonderland stories, confirms with its appearance a decades-old theory about the collapse of monopolies. In particular, they decay into a ring-shaped vortex in which every other monopole passing through its center is converted into its opposite magnetic charges.
In this article, we will examine the latest findings published in Nature Communications by Professors Mikko Möt Töpfen from Aalto University and David Hall from Amherst College.
Lay the theoretical foundations
“This was the first time our collaboration was able to create Alice rings in nature, which was a monumental achievement,” said Möt Töpfen. “This fundamental research opens new doors to understanding how these structures and their analogues function in the universe,” added David Hall.
The long-standing collaboration, titled “Monopoly Collaboration,” first proved the existence of a quantum analog of the magnetic monopole in 2014, isolated quantum monopoles in 2015, and finally observed the decay of one into the other in 2017.
Monopolies remain an elusive concept in the field of quantum physics. As the name suggests, monopoles are the single counterpart of dipoles, carrying a positive charge at their north pole and a negative charge at their south pole. In contrast, a monopole only carries a positive or negative charge.
Realization of a true monopoly
Although the concept seems simple, achieving a true monopoly has proven to be a career-defining task. This is what the Monopole collaboration did: They manipulated a prepared rubidium gas into a non-magnetic state near absolute zero. Under these extreme conditions, they then managed to create a monopole by directing a zero point of a three-dimensional magnetic field into the quantum gas.
Highlighting Alice’s ring
These quantum monopoles are naturally short-lived and dissipate within milliseconds of their creation. It is in this instability that Alice’s ring takes shape.
“Imagine the monopoly as an egg balancing on a hill,” MötTONen said. “The slightest disturbance can lead to a crash. Similarly, monopoles are exposed to noise that triggers their decay into Alice rings.”
Although monopoles are short-lived, the research group simulated that Alice rings remain stable for 84 milliseconds – more than 20 times longer than the monopole’s lifetime. This leaves researchers optimistic that future experiments will reveal even more special properties of the Alice rings.
“From a distance, Alice’s ring just looks like a monopoly, but the world takes on a different shape when you look through the center of the ring,” Hall said.
“From this perspective, everything appears mirrored, as if the ring were a gateway to a world of antimatter instead of matter,” MötTONen added.
Theoretically, a monopoly passing through the center of an Alice ring would turn into an oppositely charged antimonopoly. This would also change the charge of the Alice ring. Although this phenomenon has not yet been observed experimentally, Möt Töpfen said that the topological structure of Alice rings requires this behavior.
The experimental work was carried out at Amherst College primarily by graduate students Alina Blinova and Hall, while Mötönn and his team were responsible for matching simulations. In this way, both teams were able to confirm the interpretation of the experimental observations.
“It is simply incredible to have such an important discovery as the highlight of my doctoral research,” concluded Alina Blinova.
synthetic
The discovery of the Alice ring by the Monopole collaboration is a major advance in the understanding of magnetic monopoles and their decay in quantum physics. This vortex ring confirms decades of theory about the behavior of monopoles. Although fleeting, these structures offer a fascinating glimpse into a mirror world of antimatter. Future experiments will certainly reveal further surprising properties of these quantum rings.
For better understanding
What is a magnetic monopole?
A magnetic monopole is a particle that carries a single magnetic charge, positive or negative, as opposed to magnetic dipoles, which have two oppositely charged poles.
Magnetic monopoles decay unstably into vortex rings called “Alice rings.” This decay occurs within milliseconds.
What is an Alice Ring?
An Alice ring is the vortex structure formed when a magnetic monopole decays. It has mirror properties compared to normal matter.
The Monopole collaboration created quantum magnetic monopoles in ultracold rubidium gas and then observed their decay into Alice rings.
What is the significance of this discovery?
This discovery opens new perspectives for understanding the behavior of monopoles and similar structures in quantum physics.
The simulations carried out at Aalto University were made possible thanks to the support of the CSC – IT Center for Science and the Research Council of Finland through its Center of Excellence in Quantum Technology, as well as the American experiments with financial support from the National Science Foundation.
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