[HN Gopher] Physicists Magnetize a Material with Light
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       Physicists Magnetize a Material with Light
        
       Author : thunderbong
       Score  : 154 points
       Date   : 2025-01-07 17:54 UTC (1 days ago)
        
 (HTM) web link (news.mit.edu)
 (TXT) w3m dump (news.mit.edu)
        
       | physicsguy wrote:
       | > scientists believe antiferromagnetic materials could be a more
       | robust alternative to existing magnetic-based storage
       | technologies
       | 
       | Scientists working on interesting anti-ferromagnetic materials
       | need a justification for doing so under the crazy grant system we
       | operate, more like.
       | 
       | The downside of antiferromagnetic data storage, or skyrmion
       | storage, or any of the other various ideas recently, is that
       | reading the data is very difficult even if it is present, to the
       | point of making a real world device pretty much practically
       | impossible. I know, I also worked on this sort of thing before
       | leaving academia!
        
         | reillys wrote:
         | Knowledge in itself is good. We don't need everything to have a
         | direct commercial application. In fact most discoveries by
         | their nature do not have directly applicable commercial
         | applications.
        
           | nick__m wrote:
           | I agree and I am sure physicguy also agree but, alas, those
           | who manage the grants system frequently don't.
        
             | lukan wrote:
             | Because those who pay for the taxes frequently don't. So
             | some justification needs to happen to spend other peoples
             | money. A better way would be nice, though.
        
               | westmeal wrote:
               | Divert a percentage of military spending to a pool of
               | money for scientists to use.
        
               | lukan wrote:
               | What do the taxpayers say?
               | 
               | (Me I say yes! But I learned, I usually do not represent
               | a majority)
        
               | superturkey650 wrote:
               | Isn't that what government grants essentially already
               | are?
        
               | gmueckl wrote:
               | In the US, maybe. But other countries don't need to
               | launder research money through their defense budgets.
        
               | dinkumthinkum wrote:
               | Many such countries have their defense subsidized by the
               | US.
        
               | virgilp wrote:
               | Well we're getting into political territory, but recently
               | that "subsidized" seems to have swiftly changed to
               | "threatened", so, I don't know. What you say used to be
               | true in the past, but it's not so clear anymore.
               | 
               | Also: only country that ever invoked article 5 was
               | actually the US. In that sense the opposite is true
               | ("lots of countries have subsidized US defense"). The US
               | "subsidy" came from the strong conviction that "US would
               | act if we needed it", but that conviction is quickly
               | evaporating.
        
               | DrScientist wrote:
               | On the other hand the US is running a large deficit and
               | has a large debt - >120% of GDP - so that spend is in
               | part other people's money.
               | 
               | With the foreign countries holding the most US debt being
               | Japan, China, UK, Luxembourg and Canada.
               | 
               | I would also point out that you could view US bases in
               | places like Japan or Chagos Islands as 'subsidising'
               | local defence or it could be viewed as simple occupation.
        
               | devmor wrote:
               | Do you believe the US receives no economic benefit from
               | that defense, or that it is providing said defense at a
               | loss?
        
               | Tostino wrote:
               | Yeah, let's go back to heavily armed European countries
               | at each other's necks every couple decades... The US
               | benefits immensely from having a stable and not terribly
               | militaristic trading bloc.
        
               | Loughla wrote:
               | How is it laundering if the research has an explicit use
               | for the military? I'm confused on your point.
        
               | jachee wrote:
               | It would be nice if the research could be just for the
               | general public good instead of having to have an explicit
               | use for the military to get the money.
        
               | kevin_thibedeau wrote:
               | You're using a military technology to communicate that
               | thought.
        
               | jachee wrote:
               | Imagine how much better it would've been if not for the
               | military involvement. Imagine how many things developed
               | purely to enhance the efficiency of destroying other
               | humans could have been developed instead to enhance and
               | improve lives instead. So many trillions wasted on
               | imaginary borders and in service of imaginary friends
               | over the last... ever.
        
               | vlovich123 wrote:
               | And yet time and time again we see science struggle to
               | move forward in meaningful ways unless there is conflict
               | / the military funds it.
        
               | devmor wrote:
               | How do you explain scientific advancement in less armed
               | nations? Some of the most advanced research in the world
               | happens in states with incredibly small forces.
               | 
               | Perhaps you've confused the economic advantage of a
               | militaristic state with a connection between military
               | science and progress.
        
               | Ma8ee wrote:
               | What a load off bull! Most fundamental discoveries have
               | been independent of conflicts.
        
               | mnky9800n wrote:
               | This is a popular argument but there are plenty of things
               | that cost orders of magnitude more taxes that go towards
               | projects that lots of people don't agree with. Americas
               | trillion dollar war machine for example.
        
               | babycheetahbite wrote:
               | Well put. But, of course many on here don't have time for
               | the concerns of simpleton non-elites, and whether they
               | should have a say about where their money goes; I've
               | noticed lately I look for the greyed out comments first
               | on HN.
        
           | thecoppinger wrote:
           | Here's an excellent lecture that drives this point home:
           | 
           | "Physics in the Interest of Society Lecture 2019: John
           | Parmentola"
           | 
           | https://www.youtube.com/watch?v=sx-55BhuFks
        
           | mnky9800n wrote:
           | You are correct. Please try to convince grant agencies that
           | blue sky research doesn't need direct application.
        
         | HenryBemis wrote:
         | Like every other scientific discovery, weaponize it. I can
         | imagine a few ways that one can disable advanced weaponry or
         | cause harmful/adverse effects to weaponry, computer systems,
         | and/or ammunition. I imagine that such a solution would cause
         | the desired harm something without leaving a trace.
         | 
         | I don't see "distance" mentioned on the article, but I did see
         | a temperature (118 K = -155 C)(which make it (currently)
         | impossible to use outside a lab). The breakthrough is here
         | though, and now someone must already be at work to see if this
         | can be operated in battlefield/real-life conditions.
         | 
         | I remember on TBBT when they made a gyroscope-thingie-invention
         | but it was 'THIS' big, and the army officer was pressing them
         | to remake it 'that' small so it can be fitted on missiles (or
         | whatever). Isn't this how it typically happens?
        
       | qoez wrote:
       | Maybe the outlandish future star trek etc promised will come into
       | fruition after all
        
       | anthk wrote:
       | Current Physics look like a Zorkian/Discworldian tale.
        
         | Terr_ wrote:
         | At least for Discworld, I'd argue the causation was the other
         | way around: The books parodied real things, often injecting a
         | fantastic aspect with the subtext of "All you people in the
         | real world should be a lot more amazed at what's going on
         | here."
         | 
         | For example, "hyphenated silicon" (semiconductor doping)
         | involved in how rock trolls think, and the catch-all
         | explanation of "because quantum."
        
           | anthk wrote:
           | Zork adventures too. They parodied learning system
           | commands/programming with in-game spells.
        
       | okwhateverdude wrote:
       | > the team worked with FePS3 -- a material that transitions to an
       | antiferromagnetic phase at a critical temperature of around 118
       | kelvins (-247 degrees Fahrenheit). > [...] > They placed the
       | sample in a vacuum chamber and cooled it down to temperatures at
       | and below 118 K.
       | 
       | I feel like this massive caveat was buried half way through the
       | article. This is why I dislike university press. I mean, the
       | wizardry is impressive, but it isn't gonna revolutionize anything
       | anytime soon if it requires a vacuum and liquid Krypton-ish
       | temperatures.
        
         | hanniabu wrote:
         | Could be useful in space where those are the default conditions
        
           | chongli wrote:
           | Space is a fantastic insulator. Space suits for astronauts
           | have to be cooled, not heated.
        
             | syntaxing wrote:
             | I think it's more appropriate to say conduction and
             | convection doesn't work well. When you have a suit, it's
             | meant to block radiation and that's the mode of heat
             | transfer in space. If space was a fantastic insulator, the
             | suit itself would eventually overheat since you have to
             | remove the heat somehow (they boil off water in vacuum
             | similar to sweat).
        
         | Tade0 wrote:
         | It's not that bad - 118K is slightly above the boiling point of
         | LNG(~112K), so achievable at scale.
        
         | mjfl wrote:
         | It's basic research
        
         | pbhjpbhj wrote:
         | >but it isn't gonna revolutionize anything anytime soon
         | 
         | Reminds me of CCD. Back in the day CCD only worked effectively
         | at liquid nitrogen temperatures; a couple of decades of
         | development and you could have one in a pocket camera.
         | 
         | Maybe that's what you meant.
        
           | okwhateverdude wrote:
           | Indeed, that is what I meant. This is a neat result, just not
           | practical yet.
        
           | Ma8ee wrote:
           | We are on the other hand still waiting for the room
           | temperature super conductor and the fusion reactors. I'd say
           | that most interesting breakthroughs never reach the stage
           | where they are useful.
        
         | mensetmanusman wrote:
         | So it works at room temperature in low earth orbit.
        
           | floxy wrote:
           | Because of solar radiation, you have to take special measures
           | with heat shields, etc, to achieve low temperatures in low
           | earth orbit.
           | 
           | https://www.grc.nasa.gov/WWW/k-12/Numbers/Math/Mathematical_.
           | ..
        
         | kolanos wrote:
         | Could it have a practical use in space? Which is both already a
         | vacuum and close to absolute zero temperature wise?
        
           | idunnoman1222 wrote:
           | A practical application of storing data in space that could
           | just easily be beamed to earth to be stored?
        
             | r3trohack3r wrote:
             | From everything I'm seeing so far, all protocols for space
             | are stateful to deal with the incredibly high latency.
             | 
             | I can see a future where the space between earth and mars
             | is a constellation of massive caching servers.
        
               | worthless-trash wrote:
               | Please, we can only get so excited.
        
               | m463 wrote:
               | you could have rotating disks that can encode data as
               | they turn towards the sun.
               | 
               | Or the sun's light could drive the rotation using
               | magnetic force.
        
         | megablast wrote:
         | Exactly. I can't believe they published something if we can't
         | buy it and use it right now.
        
         | 52-6F-62 wrote:
         | That's good. Ideally we won't have a scattering of profit
         | seeking engineering firms casting magnetic fields everywhere
         | when we have the most cursory scientific understanding of high
         | spin metals in the brain.
         | 
         | If anything, we might reassess our current usage...
         | 
         | https://pmc.ncbi.nlm.nih.gov/articles/PMC8189590/
         | 
         | https://web.stanford.edu/group/solomon/research.html
         | 
         | https://www.sciencedirect.com/science/article/pii/S266652202...
        
       | skywal_l wrote:
       | Tractor beam!
        
         | busyant wrote:
         | Given your comment, you may like this:
         | https://en.wikipedia.org/wiki/Optical_tweezers
        
       | neuroelectron wrote:
       | Terahertz radiation falls in between infrared radiation and
       | microwave radiation in the electromagnetic spectrum, and it
       | shares some properties with each of these. I find it weird they
       | used this term throughout the article.
        
         | DarkSucker wrote:
         | Thanks! I'm sick and couldn't bring myself to do the wavelength
         | calculation. Your comment helped my thoughts. I think people
         | working on microwave equipment (frequency counters, ...) work
         | in Hz.That's probably why they used the term.
        
       | kleiba wrote:
       | Gotta love the picture of the three, because it is not staged.
        
         | Nevermark wrote:
         | It is hard to stage an unstaged photo. You would have to hide
         | behind some equipment and wait for them to work, and at the
         | same time, on the same thing. Hopefully when it was going well.
         | 
         | Wild life photographers probably have some tips.
        
       | brcmthrowaway wrote:
       | Isnt all light terahertz light?
        
         | spauldo wrote:
         | Only if you define light as radiation your eyes are sensitive
         | to. In scientific articles, it usually means all frequencies.
        
         | tempodox wrote:
         | Nope, terahertz range, even 999.9 THz, is way too low a
         | frequency to be visible as light for us.
        
       | westurner wrote:
       | "Researchers discover new material for optically-controlled
       | magnetic memory" (2024) https://phys.org/news/2024-08-material-
       | optically-magnetic-me... ..
       | 
       | "Distinguishing surface and bulk electromagnetism via their
       | dynamics in an intrinsic magnetic topological insulator" (2024)
       | https://www.science.org/doi/10.1126/sciadv.adn5696
       | 
       | > _MnBi2Te4_
       | 
       | ScholarlyArticle: "Terahertz field-induced metastable
       | magnetization near criticality in FePS3" (2024)
       | https://www.nature.com/articles/s41586-024-08226-x
       | 
       | "Room temperature chirality switching and detection in a
       | _helimagnetic_ MnAu2 thin film " (2024)
       | https://www.nature.com/articles/s41467-024-46326-4 ..
       | https://scitechdaily.com/memory-breakthrough-helical-magnets...
       | .. https://news.ycombinator.com/item?id=41921153
        
       | bilsbie wrote:
       | Can we create matter from light?
        
         | philipkglass wrote:
         | Indeed we can:
         | 
         | https://www.energy.gov/science/np/articles/making-matter-col...
         | 
         |  _Scientists find strong evidence for the long-predicted Breit-
         | Wheeler effect--generating matter and antimatter from
         | collisions of real photons._
        
           | westurner wrote:
           | Breit-Wheeler process > Experimental observations: https://en
           | .wikipedia.org/wiki/Breit%E2%80%93Wheeler_process#...
        
       | hexo wrote:
       | hm, electromagnetic field is light. it was light all the time.
        
       | anyfoo wrote:
       | So instead of magneto-optic media, we can now have opto-magnetic
       | media?
        
       | metalman wrote:
       | a material
       | 
       | keep in mind that ALL materials are photo reactive in one way or
       | another, and that the realistic number of possible materials, is
       | infinite* All materials are conductive in some way or condition,
       | think : superconductors . Molecular strength engineering
       | materials are something else waiting in the wings of material
       | sciences. Main point is that, this is still early days with the
       | full effects of bench top vs building size equipment used in
       | research, to show.
       | 
       | * hugely, massive, wow big make you dizzy, number
        
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