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Looks like a few days ago (5th December 2023) a research team discovered “emergent magnetic charge” in antiferromagnetic materials, and the result was published on Nature Materials.

The finding was also covered on other sites, often with less reserved titles, such as this one on the website of Cambridge University (the institution with which the researchers are associated) that says

Researchers have discovered magnetic monopoles – isolated magnetic charges – in a material closely related to rust…

What does “emergent magnetic monopole” mean here? Does this finding really show the existence of isolated magnetic monopoles?

Qmechanic
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Jonathan Huang
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To put it simply, an emergent property is a property that stems from many parts of a system all working in some collaboration that produces a whole that is greater than the sum of its parts as it were.The second law of thermodynaimcs is an example of an emergent property of large particle ensembles. The monoploes discovered in the recent research are not real paricles like those hypothesized by Dirac to explain the quantization of charge, they are "quasi-particles"; an emergent phenomenon produced by ordinary matter. So, no need to revise Maxwell's equations just yet!

Albertus Magnus
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The word $\textit{emergent}$ is used in the condensed matter community to emphasize that it comes about from many-body physics. It's not a fundamental property of the elementary particles or atoms. I would say superconductivity and liquid water fall under emergent properties. So in your case $\textit{emergent}$ is a buzzword that is synonymous with $\textit{made in a material}$.

I only skimmed the nature paper, but I don't think the essential physics has changed in the past decade when I last looked into these. Magnetic monopoles in materials are formed from chains of magnetic dipoles. The magentic field mostly cancels along the chain. In a very loose cartoon picture, this makes the ends of the chain appear to look like monopoles. They are not of course. They are not "isolated magnetic charges".

Dr. Nate
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Let's begin that magnetic monopoles were predicted by theory in 1968 year,- almost half century ago.

Magnetic monopole can be formed only by a completely new elementary particles or quasi-particles, which was achieved in this mentioned research. They have noticed that in "topological defects rich" material, on the right conditions, quasi-particle meron can be created ("emergent" part) which is a collective alignment of spins towards/outwards a topological defect,- so called anti-clockwise/clockwise Bloch meron. Which basically is a magnetic $N/S$ monopole charge.

Agnius Vasiliauskas
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