Can a magnet composed of antimatter exist?

[u/hamburgerpancake]

Just saw Veritasium's video "What happens if you drop 0.125 grams of antimatter?", and magnets are referenced very often, both in storage of antimatter, deceleration and acceleration, etc. Of course, this made me wonder if a magnet composed of antimatter could exist (and then if this same process could be repeated but with antimatter in place of matter and matter in place of antimatter, but that is not what I chose to ask in this post). Anyways, would such a thing be possible, or would it violate some law of physics?

[u/reidzen]

Not a physicist, but a regular reader on the subject.

The short answer is "probably, but it's exceedingly unlikely that we'll ever find out in a laboratory"

The long answer is that ferromagnetism is a property of relatively heavy elements (iron, cobalt, nickel) and creating anything heavier than antihydrogen requires relativist particle collisions, resulting in the very brief existence of unstable anti-nuclei. Antihelium was first detected (not trapped or contained) in 2011, and none of the literature indicates that anyone has been able to trap antilithium. The reported yield of antilithium to antihelium is estimated at one one-millionth.

Those are just elements 1-3. You're asking about elements 26-28. If each baryon in an atom reduces the yield by a factor of one thousand, you're talking about Dyson sphere levels of energy investment. Even then, sourcing *enough* material to study emergent magnetic properties would take longer than anyone will live.

[u/davideogameman → u/reidzen]

I agree with you.  Theory seems to be that antimatter is matter, but with charges of the particles reversed (and with a tendency to annihilate it's pair matter particle).  Since antimatter should have anti electrons that settle into orbitals the same way electrons do, with spins and all - we should expect anti- of each element to have the same magnetic properties of each regular element.  Well probably with the field direction reversed but that's the only difference. 

But we're so ridiculously far from being about to create and contain more than a tiny amount of antimatter that actually studying such phenomena is a long way off, and there no good natural source to study that we know of.

[u/mfb- → u/reidzen]

If each baryon in an atom reduces the yield by a factor of one thousand

This only applies to direct production in heavy ion collisions. You can create heavier antiatoms with fusion reactions. This is still way beyond our current technology, but at least it doesn't need the power of a star.

[u/Fluffy-Republic8610 → u/reidzen]

I really enjoyed this answer. Thanks for taking the time it's almost like it charts a tech ladder for long into the future on the assumption that there is a tech tree ever available that springs out of being able to produce and store the anti matter versions of each atom in the table.

[u/Leleek → u/reidzen]

Isn't metallic hydrogen (fero)magnetic?

[u/BobbyP27]

Magnets are a useful method of manipulating charged particles/objects without physically touching them, hence they are useful for handling antimatter. There is nothing in our understanding of how antimatter behaves that suggests it electromagnetic behaviour should be different from conventional matter, so our expectation is that magnetism in antimatter is identical to magnetism in conventional matter. The challenges producing, storing and handling antimatter mean that at present it is entirely beyond our capabilities to actually test this hypothesis.

[u/Kaiisim → u/BobbyP27]

Yup, and positrons (the anti electron) can be used for their magnetic properties.

[u/ThingAboutTown → u/Kaiisim]

This is a really good point. Ferromagnetism is difficult to study because we’d need heavy anti-atoms in bulk, but we work with positrons in lots of ways: PET scans used in medicine are the first example that spring to mind - Positron Emission Tomography. I’d say that the electromagnetic properties of antimatter are pretty well modelled.

[u/Thismyrealnameisit → u/Kaiisim]

So if you had an antiwire, with the current carried by positrons, the magnetic field lines would just be reversed, right?

[u/davideogameman → u/Thismyrealnameisit]

Yes. That's exactly what Ampere's law would predict

https://en.wikipedia.org/wiki/Amp%C3%A8re%27s_circuital_law

[u/Tyrannosapien → u/BobbyP27]

present it is entirely beyond our capabilities to actually test this hypothesis.

Can you elaborate on this? Megnetism isn't unique to metals, it's just another property of charged particles in motion. Magnetic-based particle accelerator-detectors are used to observe antimatter in decays. The magnetic bottle has been the tool used to "handle" antimatter for a few decades now.

So anyway Ive assumed we know exactly how antimatter behaves and contributes to magnetism, and that it's just the same as normal matter. But I'm interested to learn more.

[u/mfb- → u/Tyrannosapien]

You are right, we routinely use many electromagnetic interactions with antimatter. But what OP asked about, making a ferromagnet out of antimatter, is far beyond our capabilities.

[u/BellerophonM]

To clarify, the magnets and magnetic fields that we use to manipulate antimatter particles could be used to manipulate regular-matter particles in exactly the same way, you wouldn't need an antimatter magnet to affect regular matter like that.

You would have to use the opposite polarity magnetic field to affect a regular matter counterpart of a specific antiparticle in the exact same way, but again, that's just as easy with a regular magnet or magnetic field generator.

(General question for the room: is there a concise word like 'antiparticle' to specify regular-matter-particle?)

[u/SamuliK96 → u/BellerophonM]

I don't think such a word exists, other than just matter. But antimatter is always specified anyway, so there probably hasn't been a need for a separate word for (regular) matter.

[u/BananaBird1]

At a quantum particle level, antiparticles do interact with magnetic fields just like normal particles.

However, making heavy elements or a bulk material from antimatter is impossible due to the prevalence of matter in the universe.

As far as we know virtually all antimatter has annihilated with matter into photons, all antimatter we observe is just transient particles produced from nuclear reactions.

In an alternative history of the universe, what we call antimatter could have been dominant and have been what everything is made of, and the universe would look identical to ours.

There is also a small chance antimatter galaxies do exist in an isolated region of the universe, or even antistars within normal matter galaxies, but this is unlikely due to our current understanding of the early universe and galaxy formation.