Altermagnets: The first new type of magnet in nearly a century

https://www.newscientist.com/article/2487013-weve-discovered-a-new-kind-of-magnetism-what-can-we-do-with-it/

by Brajeshwar • 1 year ago

405 115 1 year ago

newscientist.com

neonate• 1 year ago

https://web.archive.org/web/20250716005935/https://www.newsc...

https://archive.ph/ObokU

nailer• 1 year ago

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.

russellbeattie• 1 year ago

Thank you!! I didn't see the enlarged version of the image and was wondering if that had made a mistake.

card_zero2• 1 year ago

It's a New Scientist diagram, so it's still going to be wrong somehow. We have the quantum "up" and "down", which are not actual directions. The diagram has arrows pointing up or down. Redundantly, every atom with an up arrow is red and every atom with a down arrow is blue. The article also speaks of "enough atoms with magnetic moments pointing in the same direction" to create a strong field, which I think is a literal direction. Then it speaks of "magnetic arrows", presumably a term invented for the article which could mean anything. Then it also speaks of "rotated atoms". Does an atom have a direction? The diagram has oval blobs around the atoms. These rotate alternatingly in the altermagnet. But the arrows don't rotate. So what are the blobs, and what are the arrows?

vpribish• 1 year ago

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• 1 year ago

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."

abtinf• 1 year ago

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.

srcnkcl• 1 year ago

Reads like Turbo Encabulator... maybe on purpose?

MengerSponge• 1 year ago

This makes me want to write a conference talk "Towards a turbo encabulator"

https://en.wikipedia.org/wiki/Turbo_encabulator

rockskon• 1 year ago

Can it be used to supply inverse reactive current for use in unilateral phase detractors while also being capable of automatically synchronizing cardinal grammeters?

legohead• 1 year ago

"the crystal structure results in zero magnetisation."

WalterBright• 1 year ago

That would be TNG. The original Star Trek didn't use <insert technobabble here> in the scripts.

olddustytrail6• 1 year ago

"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?

phatskat• 1 year ago

Reminds me of this quote from the esteemed Leslie Claret

Sell them on the structure. You can talk about it with confidence. Keep it simple. A little something like this, John. Hey. Let me walk you through the Donnelly nut spacing and crack system rim-riding rip configuration. Using a field of half-C sprats, and brass-fitted nickel slits, our bracketed caps, and splay-flexed brace columns vent dampers to dampening hatch depths of one half meter from the damper crown to the spurve plinths. How? Well, we bolster twelve husk nuts to each girldle-jerry, while flex tandems press a task apparatus of ten vertically composited patch-hamplers. Then, pin-flam-fastened pan traps at both maiden-apexes of the jim-joist. A little something like that, Lakeman.

cogman10• 1 year ago

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• 1 year ago

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• 1 year ago

That line is worth a dollar of subscription,

pedro_caetano• 1 year ago

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?

foota• 1 year ago

Note that you can actually flip the magnetic field of certain "normal" magnetic materials: https://www.nature.com/articles/s41563-022-01354-7

olddustytrail6• 1 year ago

That's kind of what the article is talking about. You can do it in a ferromagnetic material (like in your link) but then you've got the problem that it's a magnet and screwing up everything around it.

The idea here is that you can do it in something that is overall neutral.

fc417fc8027• 1 year ago

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.

Didn't we already play this exact scenario out with 3D XPoint? Is there any expectation that this new type of magnet will be able to compete with flash memory on a unit cost basis?

Actually I guess data retention when unpowered was one year or less but still, is that factor ultimately what led to its discontinuation? I doubt it. For long term data retention you're competing with magnetic tape which has a shelf life measured in decades and an impressively low cost per bit.

vlovich1232• 1 year ago

3D XPoint wasn't based on magnetic storage and was intentionally targeting a point between NVRAM and DRAM both in terms of price and performance.

BTW, I'm assuming you know but spinning disks are magnetic storage and even today are cheaper than flash memory on a unit cost basis. Generally there's a pretty clear tradeoff you make on all of these primarily around price vs performance (durability tends to be secondary until you get to tape storage).

Actually I guess data retention when unpowered was one year or less but still, is that factor ultimately what led to its discontinuation?

I am unable to find any actual specific numbers for flash or XPoint. There's just a bunch of unsubstantiated rumors ranging from 3 months, to 1 year, to 5 years, to 10 years. The factors that led to discontinuation is the same as for any product - the market for it never materialized and the cost of continued investment wasn't worth it. Even if it was profitable (not sure), there is always still the opportunity cost of investing that money in a higher ROI venture. Of course, this is Intel who continually failed to sustain long-term payoffs and strategic investments.

jasonthorsness• 1 year ago

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.

physicsguy2• 1 year ago

I did my PhD in this area. It’s very difficult to “read” information stored when there is no net magnetism. Hard drives are built using a read head that detects the stray field from ferromagnetic materials.

When there are particular topological textures like skyrmions you do get a spin hall effect which is quantised but in applying currents you also change the magnetisation through something called spin transfer torque.

vanderZwan5• 1 year ago

So any read operation would likely have to be a read-write operation in practice, essentially?

searine• 1 year ago

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)

pbhjpbhj2• 1 year ago

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• 1 year ago

Norway basically. Nearly every other country just throws the money back into the general fund or accumulates it at the top.

pjc502• 1 year ago

but which country has made the most for it's citizens from [technology] IP?

Post-1950 this is unambiguously the United States.

vanderZwan5• 1 year ago

Well, ASML is Dutch and started as a spin-off of government-funded research IIRC, but I don't know how big it is in terms of national GDP. On the other hand, the chips their machines enable also represents the kind of wealth not captured in money alone.

godelski17• 1 year ago

  > 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.

Can we stop referring to ArXiv papers third way? And for the love of God, just link the fucking abstract, never NEVER link the html![0] You just change {html,pdf} -> abs

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

[0] https://arxiv.org/abs/2309.01607

gus_massa• 1 year ago

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.

mindcrime• 1 year ago

I think you need an invitation to create an account,

Anybody can create an account on arXiv.[1][2] However, having an account and uploading are different things. Strictly speaking, you have to be endorsed to submit a paper. But some endorsements are granted automatically, based on various criteria. So not everybody has to go explicitly ask people for an endorsement:

arXiv requires that users be endorsed before submitting their first paper to a category.

arXiv may give some people automatic endorsements based on subject area, topic, previous submissions, and academic affiliation. In most cases, automatic endorsement is given to authors from known academic institutions and research facilities.

Generally speaking, the "word on the street" is that it's as simple as "register with a .edu email address and you get auto endorsed, otherwise you don't." But I think the reality is slightly more complex than that. Although the exact details are kept private, probably at least in part to prevent people from gaming the system.

Note that the page encourages you to register with an "institutional" email address, but doesn't specifically say it has to be a .edu one.

arXiv submitters are therefore encouraged to associate an institutional email address, if they have one, with their arXiv account. This will expedite the endorsement process.

[1] https://info.arxiv.org/help/registerhelp.html

[2] https://arxiv.org/user/register

godelski17• 1 year ago

I think you're right to nitpick, but nitpicking the wrong thing.

  > and not send it to any journal.

This, doesn't matter.

The main point of my comment is "journal != peers reading the work". Which, of course, you could even say is true about ArXiv (fine to nitpick[0]). You can put on ArXiv and no one will read it or the only people who read it are not peers. You're right that submitting to a journal or conference (nearly) guarantees someone has read the paper.

The thing though is "peer" is weakly defined. I recognize that it is contextually defined, but I'd hope from the context of my comment you can tell that I'm using "peer" to mean "another person well versed in the niche topic of the paper." This is different from "a person well versed in the topic of the paper." The niche matters. I explain more in this comment[1]

Or to put it differently, just because someone read it doesn't mean they /read/ it.

[0] I'll revise the quoted text to "Just because it is on ArXiv doesn't mean peers aren't or haven't reviewed it". Though we can nitpick a little more and say that if there are more than one author on the paper, a peer has been much more likely to have reviewed the work (not all co-authors review the works they are authors on...)

[1] https://news.ycombinator.com/item?id=44587535

devmor2• 1 year ago

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.

xondono3• 1 year ago

Technically speaking, being published means at least the editors have reviewed. The quality of their reviews is another thing entirely.

tensor3• 1 year ago

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.

godelski17• 1 year ago

You're right. You can publish into the void.

I was hoping what was said would be easily interpreted but I was incorrect. I'll revise to "putting on ArXiv doesn't mean peers haven't reviewed it."

For what constitutes "a peer", I describe more here[0]. The definition varies wildly, and it is not an easy problem to determine who is even qualified to review a work. Hell, it can be hard to determine if you yourself are qualified to review a work!

While I advocate for mostly abandoning the journals and conferences (or dramatic restructuring), I won't act like there's no problems with just publishing to ArXiv (or more preferably, OpenReview, since it allows commenting). But the truth is that there's no globally optimal solution to this problem. I just think the benefits outweigh the costs here. Frankly, most authors aren't publishing (posting on ArXiv or whatever) in bad faith. If anything, I think our current system incentivizes bad faith publishing, but that's a larger conversation (coupled with this one but requires talking about a few other factors).

Frankly, we just waste a lot of time and effort for little to no gain (possibly even for losses).

[0] https://news.ycombinator.com/item?id=44587535

xondono3• 1 year ago

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.

olddustytrail6• 1 year ago

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.

tensor3• 1 year ago

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.

godelski17• 1 year ago

I pretty much agree with you but wanted to nitpick this part

  > mainly the editors, who pushed for correctness and novelty.

I don't want to use the word correctness here[0], because no one checks if the work is correct. Rather, I'd say the goal is to check for wrongness. A peer reviewer cannot determine if a work is correct simply by reading it. The only way to do this is replication or by extension (which is the case of the work here. The physical verification was an extension of the earlier work). It's important to make this distinction because, as you say, it doesn't mean the work is right. Nor does it even mean the the readers think it is right.

In the past, many journals published as long as they did not think there were serious errors and were not plagiarized. Editing is completely different, where we want to make sure works are communicated correctly.

But I purposefully didn't say "novelty"

It is a trash word that means nothing. The original intent was that work wasn't redone. That you can't go in and take credit for discovering something someone else did, which we'd cal plagiarism. You could change all the words and still plagiarize.

It is VERY easy to find problems/limitations with works. All works have limitations. All works are incomplete. But are these reasons to reject? Often, no... You see the same thing on HN and it's a classic bias of STEM people. Hyperfixate on the issues. We're trained to, because that's the first step to solving problems! But that's not what matters in publishing, because we're not trying to solve all problems. We do it iteratively! It also runs counter to quickly publishing ("publish or perish") as what, you want to wait to publish till we got a grand theory of everything? And don't get me started on how bad we are at predicting impact of works and how impact often runs counter to the status quo (you can't paradigm shift by maintaining the paradigm). So we don't explore...

AND very frequently, we DO NOT WANT novelty in science. Sounds strange, but it is *critical* to science existing.

- Our goal is to figure out how things work. The causal structure of things. So this means works need to be reproducible. We *want* reproductions, but we also don't want them ad infinitum.

- We *also* want to find other ways to derive the same thing. Some reviewers will consider this novel while others won't, typically inversely related to their expertise in the field (more expert = more likely to consider novel while less expert means you can't see the nuanced differences which are important).

This greatly stifles innovation and reduces how well papers communicate their ideas.

The problem here is as we advance, nuances matter more and more. Think of it as with approximations. Calculating the first order term is usually computationally easy, with computation exponentially increasing as the order of accuracy increases. The nuances start to dominate. But by focusing on "novelty" (rather than plagiarism) we face the exact problem you mention.

  > most editors are nowadays completely out of their depth when evaluating papers,

So authors end up just making their works look more convoluted, to look more impressive and make it look less like the work that they are building on top of. High experts can see right through this and as grad students usually groan but then just become accustomed to the shit and start doing the same thing. Because, non-niche experts cannot differentiate the work that's being built upon from the new work.

It is a self-inflicted problem. As editors/reviewers we think we're doing right, but we're too dumb to see the minute (but important) differences. As authors we're just trying to get published, keep our jobs, and it's not exactly like the reviewers are "wrong". But it often just becomes a chase and does nothing to help make the papers actually better. This gets even worse with targeted acceptance rates, as it incentivizes reviewers to reject and be less nuanced. Which they're already incentivized to do because there's just so much stress and time crunch to the job anyways (including needing to rewrite papers because others did exactly this).

The targeted acceptance rates are just silly and we see the absurdity in domains like Machine Learning[1]. We have an exponentially increasing number of papers to review each year. This isn't just because there are new works, but because works are being resubmitted. Most of these conferences have 30% acceptance rates but the number of "wrong" papers is not that low. We also know the acceptance rate is very noisy for the majority of papers, where a different set of reviewers would result in a different outcome (see the multiple "NeurIPS experiment"s). You can do an easy model to see why this is bad. It just leads to more papers and if the number of reviewers stays the same, this is more reviews that need to be done per reviewer, which just exacerbates the problem. If you have 1000 fixed papers submitted each year and even a low percent of rejected works resubmitting the next year, like 10%, you actually have to review ~1075 papers. With a more realistic ~50% of rejected works getting recycled, you need to actually review ~1500 per year. Most serious authors will try a few times, and it is a common to say "just keep trying".

We don't have to do this to ourselves... It helps no one, and actually harms everyone. So... why? What are we gaining?

It's just so fucking stupid

/rant (have we even started?)

[0] I'm pretty sure we're going to agree, but we're talking in public and want to make sure we communicate with the public. Tbh, even many scientists think "correctness" is the same as "is correct"

[1] It is extra bad because the primary publishing venue is conferences. To you submit, get a review (usually 3), get to do a rebuttal (often 1 page max), and then the final decision is made. There is no real discussion so you have no real chance to explain things to near-niche experts. Worse with acceptance deadlines and overlapping deadlines between conferences. It is better in other domains since journals have conversations, but some of these problems still exist.

fc417fc8027• 1 year ago

Fully agree with you that the way much (but not all) of the publication process currently works is bad for everyone involved (including the taxpayer).

But I'd like to push back against the following.

the way we say "hasn't been peer reviewed" implies that if it has been published in a journal then it's factual.

I think that's ascribing meaning that isn't actually there. Peer review _does_ tell you something. Certainly not "guaranteed correct" or even "guaranteed high quality" but it is definitely some sort of signal to the reader. Consider that this is nothing more than proactively pointing out that a linked paper which closely resembles work that would typically be affiliated with a journal (a signal gated by an editor) be peer reviewed (another signal) and those reviews possibly made public (yet another signal) does not have any of these signals. That is to say, it's an important disclaimer in order to avoid the appearance of attempting to deceive the audience.

godelski17• 1 year ago

I don't think you're wrong, I just don't think those signals are very strong. I do think they used to be stronger, but paper discovery isn't really dominated that way anymore. Word of mouth was always common, but now that's expanded to social media as well as things like Google scholar or semantic. Hell, most journals and conferences are hard to search through. Maybe I'll land on their page from a Google search of the paper or when looking for those topics, but that's not any different from ArXiv. And truth is that I still have to do the same thing when landing in either location. I still have to read the abstract, give it a sniff test, and read it to varying depth depending on what's needed. There's a signal, I just haven't found it to be that meaningful

Animats• 1 year ago

"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• 1 year ago

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

ggm• 1 year ago

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• 1 year ago

You can save memory after turning the system off, and swap pages in after turning on.

cgannett• 1 year ago

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

solid_fuel• 1 year ago

That's true but you can get creative in a case where you don't need to page things back in from the disk. You could do something like powering off the entire system (assuming you have this kind of memory in the CPU too) while you're waiting for a disk read, if there's nothing else to do. So I could see big potential for power savings in things like phones and other battery powered devices.

pjc502• 1 year ago

FRAM exists, but is way behind the miniaturization curve, and I think is only available from TI?

program_whiz• 1 year ago

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).

hammock• 1 year ago

Yea they mentioned it in the article. Antialtermagnetism

eccentricwind• 1 year ago

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.

Chief_Searcha• 1 year ago

Yep that's pretty much my take on any scientific article. It's really hard to tell which of these things you'll hear about 10 years down the line.

alganet5• 1 year ago

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.

echelon_musk• 1 year ago

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.

Perhaps you should have lead with this.

alganet5• 1 year ago

I haven't said anything about magnetism. Read my comment again.

throwanem• 1 year ago

So it's an entirely new kind of magnetism, altogether?

broach• 1 year ago

(Everyone says:) “So it's an entirely new kind of magnetism!”

Thank you, _Airplane!_

https://youtu.be/0wxp-NxJny8

jepj57• 1 year ago

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.12.04...

taeric• 1 year ago

I like how the headline makes it sound like we may have had an explosion of new magnet types for a while, and then that stopped for nearly a century. :D

Tossrock• 1 year ago

Weird that there was no mention of paramagnetism/diamagnetism in here.

degamad• 1 year ago

The phys.org link does have this relevant statement as to why those two are a different type of thing:

Although other types of magnetism, such as diamagnetism and paramagnetism have been categorized, these describe specific responses to externally applied magnetic fields rather than spontaneous magnetic orderings in materials.

sneakerblack• 1 year ago

This was discovered last year:

https://www.youtube.com/watch?v=D0st_6sE7Bk

vanderZwan5• 1 year ago

One of Šmejkal’s favourite pieces is Horseman, a striking picture that features an elaborate, tessellating series of mounted figures. Strangely enough, it was this piece that inspired him to predict the existence of an entirely new kind of magnetism.

I find it a little annoying that they don't show the actual artwork (although they do link to a page with it[0]), and give a description that does not really capture what the image conveys. Because upon seeing it, it immediately becomes obvious how that might inspire someone who thinks about electromagnetic fields all day. Well, obvious to people with some passing familiarity with electromagnetic fields at least.

I'm assuming copyright got in the way but even then they could have added an equivalent illustration of their own.

[0] https://escherinhetpaleis.nl/en/about-escher/escher-today/ho...

[1] https://www.nga.gov/artworks/54229-horseman (alternate link in case the first one doesn't load)

eythian• 1 year ago

That museum (Escher in het Paleis) is worth visiting if you get the chance.

vanderZwan5• 1 year ago

I'm Dutch and I have a bachelor's degree in arts, so it probably won't surprise you that have :). And yes, it is!

yencabulator• 1 year ago

Escher died in 1972, 50+ years after his death *should* let his copyright expire!

vanderZwan5• 1 year ago

In 2024, researchers led by Atasi Chakraborty, a member of Šmejkal’s research group, demonstrated that applying compressive strain to rhenium dioxide – long known to be an antiferromagnet – triggers a transition into an altermagnetic state.
What’s more, a trio of researchers at the Beijing Institute of Technology in China realised that you can also create the right internal magnetic disturbances by stacking an antiferromagnet between layers of a different material, like a sandwich.

Does anyone else find it odd that they do not name the authors of the paper[0] that showed the second discovery? (Yichen Liu, Junxi Yu, and Cheng-Cheng Liu, for the record).

[0] https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.13...

Altermagnets: The first new type of magnet in nearly a century

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