[HN Gopher] New quantum state of matter found at interface of ex...
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New quantum state of matter found at interface of exotic materials
Author : janandonly
Score : 134 points
Date : 2025-08-01 09:42 UTC (3 days ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| ankitg12 wrote:
| Anyone knows if there are examples of such states, which were
| discovered in very specific conditions in lab, to be found
| outside? Does creation/discovery of such states help in
| explaining any hitherto unexplainable observations?
| exe34 wrote:
| It never ceases to amaze me how many different effects exist in
| the Universe, waiting for us to discover/exploit. I wonder how
| many features you could comment out and we'd still be able to
| evolve, v/s how many of these quirks we depend on for even
| existing?!
| joules77 wrote:
| https://en.wikipedia.org/wiki/Pinch_(plasma_physics)
| setopt wrote:
| The precise state of matter studied in this paper I think is
| unlikely to exist "naturally".
|
| But yes there are states of matter that exist in nature but are
| just not obvious until you study them carefully in a lab. For
| example antiferromagnets exist in nature at naturally cold
| temperatures (see hematite), but unless you're looking for
| them, they just look like normal nonmagnetic solids. Thus they
| were discovered millennia after ferromagnets.
|
| But there are more exotic states that were first discovered in
| labs and later _theorized_ to exist in nature, but that have
| not yet been proven. One example of such a theory is that a
| superconductivity-like state might occur naturally in neuron
| stars: https://en.wikipedia.org/wiki/Color_superconductivity
| TheOtherHobbes wrote:
| I'll assume you meant "neutron stars."
|
| But "neuron stars" is still an intriguing typo.
| idiotsecant wrote:
| Computronium
| BobbyTables2 wrote:
| Always wondered about this.
|
| Even magnets and plasma aren't blatantly obvious until one
| sees them in action.
|
| In the early da, someone magnetizing a piece of iron must
| have seemed like utter witchcraft...
| refactor_master wrote:
| "State of matter" isn't exactly a useful description in this
| particular case, but it's interesting that enzyme catalysis
| cannot be explained fully by classical chemistry/physics alone.
|
| https://en.wikipedia.org/wiki/Quantum_tunnelling#Biology
| malux85 wrote:
| Pretty interesting, I recently build an nth order spherical
| harmonics encoder that can encode the electronic structure of a
| local environment (of n A) into a high dimensional fingerprint.
| We can then use this to search against a big TB dataset of known
| structures we built to see if we can find analogous
| configurations. I've started building the structure in the
| article, I'm interested to see what a search turns up.
| foltik wrote:
| Neat! Which spherical harmonics descriptor are you using, and
| what does your in-house TB dataset cover? What do you plan to
| do with any matches you find?
| koolba wrote:
| From the article:
|
| > Weyl semimetals are materials that allow electricity to flow in
| unusual ways with very high speed and zero energy loss because of
| special relativistic quasi-particles called Weyl fermions. Spin
| ice, on the other hand, are magnetic materials where the magnetic
| moments (tiny magnetic fields within the material) are arranged
| in a way that resembles the positions of hydrogen atoms in ice.
| When these two materials are combined, they create a
| heterostructure, composed of atomic layers of dissimilar
| materials.
|
| I'm not going to pretend to understand how any of this works.
|
| How long do you have to work in physics until you grok things
| like this? And how much longer until you get to come up with cool
| names like "spin ice".
| frutiger wrote:
| > How long do you have to work in physics until you grok things
| like this?
|
| By the end of an undergraduate degree, especially if you elect
| courses in advanced particle physics.
| nyeah wrote:
| This is solid-state, not particle physics.
| ankitml wrote:
| So your claim is spin ice as a concept doesnt exist in
| particle physics and would not be discussed outside solid
| state?
| nyeah wrote:
| I claim the article is about solid-state physics.
| Otherwise, any claim that doesn't appear in my comment
| ... ? Not my claim.
| frutiger wrote:
| Indeed. Fermions are usually taught in particle physics,
| especially when distinguishing Weyl/Majorana/Dirac
| fermions.
| jerf wrote:
| The major problem with understanding articles like this is that
| while it typically doesn't involve quantum entanglement, it's
| close enough to quantum that it makes the science writers get
| all giddy about the words they are throwing around and they do
| their usual "why inform the reader about what is going on when
| we can just make them go Gee Whiz" schtick.
|
| The key word is "quasi-particle" which is somewhat less exotic
| than it sounds. It is a combination of what you might call real
| or normal particles that produces some sort of pattern in it
| that itself acts like a particle of some sort. The resulting
| "quasi-particle" can have all kinds of interesting properties
| that normal particles can't have on their own, but what makes
| them "quasi" is that they can't exist on their own. They're
| intrinsically on top of some substrate of normal particles.
|
| One of the simplest quasiparticle is the "electron hole". Take
| a lattice of some electrically neutral substance. Remove one
| electron from it. There is now an "electron hole" in it. You
| can treat that hole like a particle now. It can "move" to
| another location by having the real electrons change places. It
| can "flow" through a series of such events. You can model a lot
| of things with "electron holes" that act in very particle-like
| ways. But they don't exist on their own. This one is simple
| because you don't even need quantum mechanics to get a hold of
| it in your head.
|
| Many more complicated scenarios are possible. Many interesting
| things can happen with them. Most, if not all, news articles
| about "new phases of matter", which science writers love to
| write about only slightly less than making "woo woo" motions
| with their fingers while talking about quantum entanglement,
| are new quasiparticles of some sort. This is somewhat less
| interesting than they think because if you include
| quasiparticles as "phases of matter" then there are already
| hundreds or thousands, but the science writer wants to write an
| article about every single one of them as if the list is now
| "solid, liquid, gas, Weyl semimetals" and then write the next
| article as if the list is now "solid, liquid, gas, ELECTRON
| HOLE" and so on and so on for each new quasiparticle.
|
| But from this perspective, the list hasn't been so short as
| "solid, liquid, gas" for well over a hundred years now, and
| while adding a new one is often good science, it has also been
| "just" another one of thousands for a while now.
|
| This post is not an explanation of "spin ice", "Wely fermions",
| or anything else; what this is is the "secret decoder ring" to
| remove the wiggly fingers and the "woo woo" noises the science
| writers add to this topic every time they write about it and to
| give you the terms you can Google and start reading up on what
| is one of the most interesting and productive fields in the
| hard sciences right now. Everyone loves to talk about how stuck
| particle physics is, but physics is making a lot of interesting
| findings in the field of making the particles we know about
| sing and dance in all sorts of new and interesting ways.
| jlokier wrote:
| _> One of the simplest quasiparticle is the "electron hole".
| Take a lattice of some electrically neutral substance. Remove
| one electron from it. There is now an "electron hole" in it.
| You can treat that hole like a particle now. It can "move" to
| another location by having the real electrons change places.
| It can "flow" through a series of such events. You can model
| a lot of things with "electron holes" that act in very
| particle-like ways. But they don't exist on their own. This
| one is simple because you don't even need quantum mechanics
| to get a hold of it in your head._
|
| An electron hole seems like a simple, almost silly idea at
| first. Isn't it just like the hole in a sliding puzzle game.
| You move a neighbouring electron into the hole, so the hole
| disappears and a new hole appears at the neighbouring
| position. It seems to "move". Does this deserve a special
| name like "quasi-particle"?
|
| But it's not like the hole in a sliding puzzle!
|
| An electron hole moves with inertia, like a real particle. It
| behaves as if it has mass: You can push it and it starts
| moving. If you push it more, it accelerates more. But unlike
| a sliding puzzle, when you stop pushing, the electron hole
| _carries on moving at the same speed_.
|
| It keeps going by itself in whatever direction it was going,
| until it's pushed in a different direction, or bounces off
| something.
|
| You can't push a sliding puzzle hole at a diagonal angle, let
| alone push it that way and then watch the puzzle hole keep on
| moving that way by itself like an independently moving
| object, as far as it can go until it hits something.
|
| If you had a large sliding puzzle with two holes, you
| wouldn't expect to be able to send them towards each other,
| bounce off each other and continue.
|
| And you certainly can't perform double slit interference with
| sliding puzzle holes. You can, in principle (hard in
| practice), make electron hole beams and interfere them.
|
| Things like holes and other patterns in matter behave
| _remarkably_ like real, coherent particles, even though they
| are just patterns.
| jerf wrote:
| Thank you for that fantastic elaboration. I'll have to put
| it in my pocket for future discussions to link to.
|
| Working with this sort of thing is on my short list of "if
| I had it to do all over again". It's really fascinating
| stuff.
| mosesbp wrote:
| If you think this is cool/valuable, I just want to point out that
| this work is being paid for by the DOE Office of Science (BES
| division), uses the NSF National High Magnetic Field Laboratory,
| and is using money from an NSF CAREER award ("Acknowledgments"
| section under "Funding" in the actual paper [1]). The former is
| facing a cut of 14% [2] (The Office of Science overall is seeing
| a similar cut), the second is facing a 40% cut [3], and the
| latter appears to be destroyed entirely (no money requested) [4]
| in documents released by these agencies for FY2026 (executive
| budget).
|
| This research is also supported by Chinese funding agencies, who
| I imagine will _not_ be engaging such senseless hamstringing of
| their national scientific organs...
|
| [1] https://www.science.org/doi/10.1126/sciadv.adr6202
|
| [2] See page 5 of
| https://www.energy.gov/sites/default/files/2025-07/doe-fy-20...
|
| [3] See page "Facilities - 5" of https://nsf-gov-
| resources.nsf.gov/files/00-NSF-FY26-CJ-Entir...
|
| [4] See page "Summary Tables - 1" of the link in [3].
| sharpshadow wrote:
| The focus for the next decades is set for war, the cuts
| everywhere are not random. I doubt that there can be done much
| in the near future.
| bn-l wrote:
| When commenters say stuff like this I never know if they mean
| grants that went to funding utter taxpayer theft like this:
| https://www.niemanlab.org/2025/04/national-science-foundatio...
|
| Or real science.
|
| So I just tune out.
| mecsred wrote:
| Considering they provided multiple references to exactly what
| they were talking about, what gave you issues? They're not
| talking about what you linked, and they are talking about
| what they linked.
| mosesbp wrote:
| Your link seems unrelated to the topic of this article? I
| gave the line items for the research conducted in the OP.
|
| A good faith reading of your comment leads me to guess you
| might take issue with a small number of unrelated NSF CAREER
| awards going to research you don't find worthwhile (such as
| those alluded to in your link). But the vast majority of
| CAREER awards fund what I would imagine you would consider
| "real science" [1], like the content of OP.
|
| So please do not tune out!
|
| [1] You can count them here in the list of all CAREER awards:
| https://www.nsf.gov/awardsearch/advancedSearchResult?PIId=&P.
| ..
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