Altermagnets: The first new type of magnet in nearly a century
43 comments
·July 16, 2025alganet
This is likely to be less important than it really is.
It reminds me of the "new state of matter discovered" kinds of articles that are known to get clicks.
https://trends.google.com/trends/explore?date=all&q=%22new%2...
And also the "vantablack" fad:
https://trends.google.com/trends/explore?date=all&q=vantabla...
Basically, any potential discovery that can barely fit the "new kind of..." usually sounds more impressive than it really is.
This article is full of it.
I'm a programmer with very basic knowledge of magnetism, so, I can't say for sure what the discovery means, or if it is a discovery at all.
cogman10
Ah, neat.
If I'm reading this right, then the real big benefit of these things would be solid state magnetic storage.
The benefit of these things is they don't create a magnetic field while they do respond to magnetic fields. That means you can pretty tightly pack these things together without concern that they'll interact with each other. A light electric pulse could determine if the bit is a 1 or a zero and a strong pulse would flip the bit.
I'm guessing that due to this nature, these things would actually have pretty long shelf lives and near infinite read/write cycles since you are, effectively, just flipping atoms around and not actually breaking structures or dumping in charge.
These should mostly work with regular silicon manufacturing. The tricky part will be how tightly you can pack these things together before the reading structures start interfering with each other.
imdsm
> A light electric pulse could determine if the bit is a 1 or a zero and a strong pulse would flip the bit.
Feynman moment. Breaking it down into one sentence. Bravo!
OhNoNotAgain_99
[dead]
pedro_caetano
> If I'm reading this right, then the real big benefit of these things would be solid state magnetic storage.
Wouldn't this also enable a much higher resolution and better noise immunity for the entire zoo of industry sensors that are based on the Hall effect?
nailer
If the anti/alter difference is not obvious the first time you see https://web.archive.org/web/20250716153436im_/https://images... look at the halo around each magnet.
jasonthorsness
The article does a decent job eventually of explaining a use-case in the section "Confirming that altermagnets exist".
Seems you can store information at high density in electron spin in materials where spins are naturally organized. However, so far the only suitable materials have been ferromagnets, which have macroscopic magnetic fields that make using them a nightmare. The new altermagnets have suitably organized spins but the atoms alternate their magnetic fields so there is no net magnetism from the material and they are easier to work with.
Animats
"However, researchers tend to feel that these clever tricks may not lead to scalable altermagnets anytime soon, as the methods are difficult to pull off."
This is a good scientific discovery, if replicated, but the hype drowns out the science.
dylan604
But that's different from a lot of announcements where after reading, you are left with the impression a viable product is right around the corner
eccentricwind
If It's not all hype and hyperbole, It could be a massive breakthrough in data storage, but It's better to remain prudent and reserve some doubt.
ggm
Analogous beliefs about new RAM models up-ending the market for memory turned out to be far slower to hit the streets, and had far less impact on the DRAM market.
I would love to have something at modern memory speed, which behaved like core: Turn off the machine, its run-state is frozen. Turn back on, the memory state is still there.
But the reality is that machines are built to DRAM, and DRAM persists as the basic memory model for the "architecture" of a system
codedokode
You can save memory after turning the system off, and swap pages in after turning on.
cgannett
even if its not faster than DRAM I wonder at what point would it just not make sense to have two separate modules. Like all the volitile storage in a system could be in the L-cache/s on the CPU and for most things that plus this faster non-volitile storage would do the trick. I wonder what kind of optimizations would have been made in a world where stuff like DRAM just didnt exist and we just had to deal with the bottlenecks of non-volitile storage media
program_whiz
Doesn't this imply a 4th type with alternating rotated atoms and aligned magnetic spin? Also seems like you could mix and match (making the effect continuously tunable at macro scale).
searine
Brought to you by the Tax Payers of Czechia, Germany, and the EU via :
* Czech Science Foundation * The Ministry of Education of the Czech Republic * European Research Council * Deutsche Forschungsgemeinschaft (German Research Foundation)
pbhjpbhj
Which raises the question -- Norway famously made its citizen fund using oil money, but which country has made the most for it's citizens from [technology] IP?
Natural resources v IP resources?
elictronic
Norway basically. Nearly every other country just throws the money back into the general fund or accumulates it at the top.
godelski
> In a paper that hasn’t yet been peer-reviewed, he and his colleagues predict the existence of yet another kind of magnetism, which he calls antialtermagnetism.
We shouldn't say "not peer reviewed" because it isn't accurate. Being published in a journal doesn't mean a work is correct nor does it mean peers read it. Putting the paper on ArXiv does mean peers are reviewing it. The point of publishing is to communicate our work to others and journals and conferences can often be harmful to that process, making researchers oversell or even avoid looking in certain directions because a few opinionated peers shoot them down. It's happened to Nobel level works too.
The review process is just fucked up. It might be able to tell you if a paper is wrong but it can't tell you if it has no mistakes or is right. I mean it took two years to confirm this one, right? (Physical validation) but the way we say "hasn't been peer reviewed" implies that if it has been published in a journal then it's factual. That's not how it works and frankly that's not how it should work.
On top of that they take money from the government, gets articles for free, don't pay reviewers (meaning the universities pay for reviewers), and have the audacity to charge people to read that work. It's basically just a scheme to extract government money.
Sorry, I really just hate the publication process. It stifles innovation and wastes so many people's time
xondono
That’s because we’ve basically reinterpreted what “peer review” is.
Peer review used to mean “some peers have reviewed it”, mainly the editors, who pushed for correctness and novelty. There was a clear difference between publishing and making a paper public. It never meant “it’s right”, but it meant “it has passed basic quality control and it’s worth your time to read it”.
Modern day academics push people to fragment into ever smaller niches, meaning most editors are nowadays completely out of their depth when evaluating papers, so now we keep referring to editor approval as “peer review” and try to diminish the public perception that comes with it.
tensor
This is not true. In most of the top journals you need at least three other practitioners in your field to read it and sign off on it. The editor finds the appropriate reviewers, manages the process, does some basic format and other types of vetting, and also will accept or reject it based on the reviews from the reviewers.
The reviewers here are the "peers", and generally are expected to be qualified experts in the area that the paper deals with.
olddustytrail
> That’s because we’ve basically reinterpreted what “peer review” is.
Who is "we" in this scenario? Because that's certainly not how I've seen peer review work.
The editor would ask a small group of people in the field to act as reviewers and then send them the papers. They review it and send it back with any requests for changes prior to publication.
So they're the peers that are reviewing, not the editor.
gus_massa
Nitpicking:
> Putting the paper on ArXiv does mean peers are reviewing it.
You can upload a pdf to the ArXiv and not send it to any journal. I think you need an invitation to create an account, but it's 99% like WordPress.
devmor
> Being published in a journal doesn't mean a work is correct nor does it mean peers read it. Putting the paper on ArXiv does mean peers are reviewing it.
Sorry I don't get what you mean by this. How does putting the paper on ArXiv mean that peers are reviewing it any more than publishing it in a journal? Both do mean that peers have the opportunity to review it, but neither guarantees it, and ArXiv is infinitely easier to upload anything to and never have it even looked at.
xondono
Technically speaking, being published means at least the editors have reviewed. The quality of their reviews is another thing entirely.
tensor
Obviously journals vary in their standards, but many of the more respected ones do require other scientists read and critique the paper. You can argue about the quality of these reviews, certainly it's a process that needs improving, but this is what "peer reviewed" means.
Trying to claim ArXiv papers are "peer reviewed" is utter nonsense. As you correctly point out, the only requirement to being on ArXiv is that someone with an account uploaded it there. There are no requirements that it passes any sort of verification or vetting process whatsoever, let alone having other scientists read and critique it.
There is a very vocal movement these days that is trying to argue that we should do away with the traditional peer review process. Apparently that sometimes includes trying to redefine the very definition of "peer review" as the OP did.
vpribish
that article reads like an internet recipe SEO honeypot.
https://en.wikipedia.org/wiki/Altermagnetism
this is an extremely esoteric thing - no net magnetism, but has some possibly-useful properties of atomic spin... useful if you're doing some spintronics, that is. maybe.
BizarroLand
After reading that article I now understand what my boomer parents felt like watching star trek for the first time.
"In condensed matter physics, altermagnetism is a type of persistent magnetic state in ideal crystals. Altermagnetic structures are collinear and crystal-symmetry compensated, resulting in zero net magnetisation. Unlike in an ordinary collinear antiferromagnet, another magnetic state with zero net magnetization, the electronic bands in an altermagnet are not Kramers degenerate, but instead depend on the wavevector in a spin-dependent way due to the intrinsic crystal symmetry connecting different magnetic sublattices."
rockskon
Can it be used to supply inverse reactive current for use in unilateral phase detractors while also being capable of automatically synchronizing cardinal grammeters?
bigbuppo
Well of course, that's why it needs Glyptal-impregnated, cyanoethylated kraft paper bushings. But use caution. The replenerative flow characteristics of positive ions in unilateral phase detractors may require the use of a quasistatic regeneration oscillator in some situations.
WalterBright
That would be TNG. The original Star Trek didn't use <insert technobabble here> in the scripts.
srcnkcl
Reads like Turbo Encabulator... maybe on purpose?
boothby
As somebody with a professional interest in spin lattices: no, it doesn't. (Also: I'm unfamiliar with the term "Kramers degenerate" and am reading up now)
olddustytrail
> "In condensed matter physics, altermagnetism is a type of persistent magnetic state in ideal crystals.
Real crystals have impurities so they are harder to reason about. An ideal crystal is just one where we pretend it's perfect.
> Altermagnetic structures are collinear
The structure is lined up, like the diagrams in the article
> and crystal-symmetry compensated, resulting in zero net magnetisation.
And the alternating lines are symmetrical so they "compensate" for each other and cancel out.
> the electronic bands in an altermagnet are not Kramers degenerate... (etc.)
The spin is different like in the diagram. Ok, that's a bit lame. Anyone else can give a simple but mostly accurate explanation?
abtinf
The writing on Wikipedia science and math articles tends to be absolutely indecipherable trash.
Trecknobabble often makes more sense than Wikipedia, at least within the context of the show.
theideaofcoffee
As someone formerly in the sciences, I can't suspend my disbelief long enough to make it through a treknobabble explanation, it's just cheesy enough where it's painful. Though I think trash to describe a lot of science and math wiki articles is a bit of a strong word. A lot of them are written by the practitioners or people with intimate knowledge so I'd 100% expect jargon so it can be impenetrable at times, that's where the references come in handy: textbooks, articles and whatnot. A bit opaque yes, but not trash.
legohead
"the crystal structure results in zero magnetisation."
?
Dylan16807
The crystal emits no magnetism as a whole, despite the different internal states it can take, because adjacent atoms cancel each other out.
Because each half of the net-zero magnet is arranged differently inside the crystal there's still a good way to measure what state it's in. Or something like that, I can see the pretty graph but I don't know what measurement you'd do.
MengerSponge
This makes me want to write a conference talk "Towards a turbo encabulator"
Timsky
Thanks for sharing this piece!
Related: https://phys.org/news/2024-02-altermagnetism-magnetism-broad..., https://www.ictp.it/news/2025/1/altermagnets-new-magnetic-ph...