10 ms·

This is an extremely useful summarization of the original paper. > The authors believe that the modified/strained structure of their material creates a large n

This is an extremely useful summarization of the original paper. > The authors believe that the modified/strained structure of their material creates a large number of “quantum wells” between particular lead atoms and the adjacent oxygens of the phosphate groups bound to them, in effect making a two-dimensional “electron gas”. They propose that electron tunneling between these quantum wells, which are between 3.7 and 6.5 Ångstroms apart, is the superconducting mechanism. I am not enough of a solid-state physicist to judge this proposal, but the authors are making a detailed mechanistic claim that is subject to experimental proof, which is very good to see, and and they adduce a good deal of data to back it up (x-ray diffraction, EPR, and more). And they demonstrate the behaviors that a superconductor should have, such as the Meissner effect (expulsion of a magnetic field), sudden resistivity changes at a critical temperature (bizarrely high though that is in this case), current-voltage (I-V) plots at different temperatures and under different magnetic field strengths, etc. If these data reproduce, the superconductivity of this material seems beyond doubt.

AndrewKemendo 3y ago
Totally agree. This is science at it's best, with maximum skepticism (and a dash of hope), in front of our eyes! Even better, it's a HUGE claim that is going to show how epistemology in science works (reproduction!!)
akjssdk 3y ago
I don't think the actual proposed superconductivity mechanism is the relevant part of this paper. It is much easier to prove that this is superconducting than to prove why. And in a sense it is a bit less relevant. Although developing a working theory for room temperature is also probably worth a Nobel prize, so I am willing to bet some theorists are also running to their blackboards as we speak.
- scarmig 3y ago
  Yeah. BCS was proposed a half century after the first conventional superconductor was discovered, and even today we don't have a convincing mechanism for "regular" high-Tc superconductors. But if it superconducts, it superconducts, and research into the how is useful but not a blocker to using it.
  - bluGill 3y ago
    That depends. If it super conducts, but it isn't useful in the real world, then we will be waiting for theory to - hopefully - give us some insight into how to improve things to useful. This only can carry a small amount of current. I'm not sure how to figure out what small means (numbers are given in the article if you know how to use them!), but if the losses using regular wire are less than the energy needed to make this stuff then it isn't useful. This is made out of lead. Even if it is useful for transmission, the difficulty of working safely with lead in a factory may mean it is impractical. Or it make leach lead into the real world making it not safe to deploy. There are probably other ways this can turn into a "it works but isn't practical" thing that would force us to wait for theory (or luck!) to point to something better. What I wrote above is what I can think of in a couple minutes. Only time will tell though, I hope it works out.
    - reaperman 3y ago
      > If it super conducts, but it isn't useful in the real world, then we will be waiting for theory to - hopefully - give us some insight into how to improve things to useful. This only can carry a small amount of current. Thank you for this. > This is made out of lead. Even if it is useful for transmission, the difficulty of working safely with lead in a factory may mean it is impractical. Have you been to a hardware store lately? A huge amount of pipe fittings for gas and non-potable water are made from lead. Factories don’t find it hard to work with lead. It might be inadvisable but it’s not hard. We can argue about the "working safely" part, but in terms of "does this make it impractical?" the answer seems to be no under the current global regulatory environment.
      - beepbopboopp 3y ago
        [flagged]
        mlyle 3y ago
        Nah. We have a reasonable understanding of fluids. It's just that the two things we say as simple explanations (the plane pushes air downwards causing an equal and opposite reaction to push the plane up; faster flow on top of the wing "sucks the plane upwards") are both only partial truths. Sometimes you get arguments between partisans for each of these two simplified explanations, but really both are bogus.
- local_issues 3y ago
  Ding ding ding! We still don't know how bikes work, we have a pretty good but incomplete model for lift on airplanes, and no one has the faintest why Tylenol works. We should figure that out! But we can definitely keep using all the applications until then. (Except for Tylenol, we keep learning how bad that stuff is) EDIT: It won't let me post more, so here's the answers to responses. For sure! https://www.cbc.ca/news/science/science-of-cycling-still-mysterious-1.3699012 https://www.cbc.ca/news/science/science-of-cycling-still-mys... http://www3.eng.cam.ac.uk/~hemh1/gyrobike.htm http://www3.eng.cam.ac.uk/~hemh1/gyrobike.htm https://www.newscientist.com/article/mg22730370-400-how-does-a-bicycle-stay-upright/ https://www.newscientist.com/article/mg22730370-400-how-does... It's a fun little fact. We know a ton about BUILDING bikes, which is a more useful tool anyway
  - mthomasmw 3y ago
    Do you have a link handy for "we don't know how bikes work" ?
    - prasadjoglekar 3y ago
      [flagged]
      - post-it 3y ago
        I'm not super interested in watching Joe Rogan and RFK, is there a particular bit where they talk about bikes?
        CSMastermind 3y ago
        There's nothing about bicycles in the video he linked.
        post-it 3y ago
        A classic Freudian clip.
- dllthomas 3y ago
  Do we know whether the mechanism was proposed before or after observing the results? If they found the material because of the theory, then I think it's very relevant.
  - beowulfey 3y ago
    Someone who speaks Korean may have to go through the original paper. It is LK-99 though; I wonder if they tried 99 other combinations first!
    - stu255 3y ago
      No, Lee and Kim first discovered the material in 1999 and have spent 20 years doing other things in between getting help to figure out how to isolate LK-99 and reproduce the correct grain structure. They eventually got a world class physical chemist, Kwon. There is now a huge bust up within the team, hence the muddled race to publish and claim credit.
      - beowulfey 3y ago
        Ahh that makes sense. I was wondering what was going on with the two papers and thought it might be something like that too. Thanks for the extra details.
  - gus_massa 3y ago
    Somewhat similar compounds are superconductors, so it's possible that a wrong theory gave them a lucky hint to modify an old superconductor into the new superconductor.
- ethn 3y ago
  They made a synthetic a priori prediction proven by experiment. In science, that's the strongest type of claim.
  - seeknotfind 3y ago
    You might also say it's the only type of claim science recognizes. Though, whatever or how strong a claim is, the question is how important is what is proven and will it lead to real superconductive materials.
  - throwawaymaths 3y ago
    The strongest type of claim is when an a priori claim is called absurd, someone goes to make observations to disprove it and comes back convinced of your theory.
- Terr_ 3y ago
  > I don't think the actual proposed superconductivity mechanism is the relevant part of this paper. Plus even if the proposed-mechanism is incorrect and even if the effect is not strong enough for practical engineering... There's value in a "real" (if weak) superconductor which is both easy to fabricate and easy to run tests on. It could become a starting-point for dozens of other tweaked formulations, enabling all sorts of not-so-expensive experiments and fresh data about how different parameters lead to different electromagnetic outcomes.
- aaron695 3y ago
  [dead]
- fnordpiglet 3y ago
  I’m not entirely sure that’s true. A posit in the paper is this is a novel super conducting mechanism and as such if the mechanism is true it’s totally unexplored. That leaves open a huge field of new research. That’s certainly a relevant part of the paper. Super conductivity at room temperature is an amazing breakthrough alone, but if it was with a clever tweak with an existing well established technique that would be the end of the story. The fact it’s an entirely new technique opens a world unexplored and indicates a pathway to even more amazing discoveries to be had (and funding for entire generations of physicists).
  - glenstein 3y ago
    Right. The mechanism itself seems extraordinary. And it seems like that mechanism is exactly the "why", the commenter is claiming is more important. Moreover, you can have more than one thing about a paper be the "relevant" thing.
- glenstein 3y ago
  >I don't think the actual proposed superconductivity mechanism is the relevant part of this paper. It is much easier to prove that this is superconducting than to prove why. As another commenter has pointed out, the proposal of a new mechanism seems to be extraordinary and novel, and could lead to an explosion of new research, so it does indeed seem to be "relevant" on its merits. I also don't see this as a case of the "why" being left unexplained. In the history of superconducting it has indeed been the case that new cocktails have led to superconductivity without the underlying why being understood. But the commenter that you're responding to quotes part of the paper that shows an awfully specific mechanism. I understand the sense in which there can be a "why" that remains to be explained in certain circumstances, even when you have a mechanism. Who do monarch butterflies have the black and orange pattern on their wings? There's a cause and effect answer but there's also a "why" answer. But with superconductivity, the mechanism is the why, unless I'm misunderstanding here. If other forms of superconductivity rely on other mechanisms, there isn't going to be a general why connecting this case to the other cases, but nor is there anything left unexplained just by explaining the "why" of this case by explaining it's extraordinary mechanism.
jpmattia 3y ago
> They propose that electron tunneling between these quantum wells, which are between 3.7 and 6.5 Ångstroms apart, is the superconducting mechanism. That is a very strange explanation. As someone who has done a decent amount of solid-state physics work, I would expect the explanation to involve a mechanism for pairing of electrons. Mere tunneling between quantum wells has been a staple since the "metamaterials" of the 80s and 90s. That said, the measured curves do not lie, and I haven't kept up with the field. So I'm all ears (and very much hoping the superconducting revolution is upon us!)
- dexwiz 3y ago
  Are you referring to a Cooper pair?
  - aqme28 3y ago
    Yeah, that’s the generally used explanation for superconductivity
    - xeonmc 3y ago
      Would it be accurate to describe it as "lattice peristalsis"?
      - aqme28 3y ago
        That’s sort of the proposed mechanism for Cooper pairs forming, but I don’t think I’d call Cooper pairs themselves “lattice peristalsis”
- deleted 3y ago
  [deleted]
arcadi7 3y ago
Short answer: talk about quantum wells in this context is meaningless .
cma 3y ago
> sudden resistivity changes at a critical temperature (bizarrely high though that is in this case) How high? Just wondering if it might eventually be possible to use it in some power/clocking distribution layers of a semiconductor chip without bulky cooling.
- jacquesm 3y ago
  127C!
- elihu 3y ago
  That's a good idea. Honestly, I find it pretty amazing that modern CPUs don't just instantly turn into a puddle of molten metal as soon as you turn them on. The critical temperature is 127 C, as the other commenter mentioned. That seems like it's high enough to be useful in a computer CPU. I suppose there might also be applications for power distribution in a data center. You might use a few large, high-efficiency low voltage DC power supplies to supply the whole site instead of hundreds or thousands of individual power supplies if electrical resistance in cables was less of an issue. (I think this sort of thing is done now, but more at the rack level, since long cable runs cause losses.) You might even use 1V power instead of 5V or 12V. (Granted, superconducting materials don't have unlimited current capacity, and bad things happen if you exceed the limit.)
  - axiomaticdoubts 3y ago
    The critical temperature is not 127 C. They did not actually measure the critical temperature. They just said it's at least 400 K (~127 C), probably because that was the maximum temperature the equipment they used could measure.
- pjc50 3y ago
  > Just wondering if it might eventually be possible to use it in some power/clocking distribution layers of a semiconductor chip There's an additional obstacle factor here which is that the material has to (a) be "sputterable" onto the surface, which may rule out things with fancy crystal requirements, and (b) not adversely react with the rest of the chip, which is why coppper is ruled out (!) and chips use aluminium for metal layers.
burtonator 3y ago
I want ONE breakthrough like this in my lifetime. Something completely game changing.
- doctorwho42 3y ago
  Live to see SPARC turn on, there are some pretty smart people with models actually showing it breaking Q>3. Turns out the hardest part about productive fusion is the sustained high compression, and HTC tape really helps increase the compression by a large amount. (See their 20 Tesla test at the start of the pandemic)
  - Helmut10001 3y ago
    Just want to mention for others: The first result for SPARC on google is SPARC (Scalable Processor Architecture), whereas SPARC (tokamak) [1] is what relates to Q>3. [1]: https://en.wikipedia.org/wiki/SPARC_(tokamak) https://en.wikipedia.org/wiki/SPARC_(tokamak)
  - deleted 3y ago
    [deleted]
  - stu255 3y ago
    Neutron damage is the real filter for fusion.
  - dgroshev 3y ago
    It would be great though if they stopped sponsoring the war in Ukraine. Yes it's unfortunate that their main HTS tape supplier is Russian, but pretending that it's not and just ignoring the issue (or obscuring the supply chain through that Japanese middleman) is pretty immoral.
  - kaashif 3y ago
    Meanwhile as someone who had to deal with writing code for Solaris and using Sun's compiler, I think I've achieved my goal by seeing my last SPARC turn _off_! But yeah, nuclear fusion is cool.

AndrewKemendo 3y ago

Totally agree. This is science at it's best, with maximum skepticism (and a dash of hope), in front of our eyes! Even better, it's a HUGE claim that is going to show how epistemology in science works (reproduction!!)

akjssdk 3y ago

I don't think the actual proposed superconductivity mechanism is the relevant part of this paper. It is much easier to prove that this is superconducting than to prove why. And in a sense it is a bit less relevant. Although developing a working theory for room temperature is also probably worth a Nobel prize, so I am willing to bet some theorists are also running to their blackboards as we speak.

scarmig 3y ago
Yeah. BCS was proposed a half century after the first conventional superconductor was discovered, and even today we don't have a convincing mechanism for "regular" high-Tc superconductors. But if it superconducts, it superconducts, and research into the how is useful but not a blocker to using it.
- bluGill 3y ago
  That depends. If it super conducts, but it isn't useful in the real world, then we will be waiting for theory to - hopefully - give us some insight into how to improve things to useful. This only can carry a small amount of current. I'm not sure how to figure out what small means (numbers are given in the article if you know how to use them!), but if the losses using regular wire are less than the energy needed to make this stuff then it isn't useful. This is made out of lead. Even if it is useful for transmission, the difficulty of working safely with lead in a factory may mean it is impractical. Or it make leach lead into the real world making it not safe to deploy. There are probably other ways this can turn into a "it works but isn't practical" thing that would force us to wait for theory (or luck!) to point to something better. What I wrote above is what I can think of in a couple minutes. Only time will tell though, I hope it works out.
  - reaperman 3y ago
    > If it super conducts, but it isn't useful in the real world, then we will be waiting for theory to - hopefully - give us some insight into how to improve things to useful. This only can carry a small amount of current. Thank you for this. > This is made out of lead. Even if it is useful for transmission, the difficulty of working safely with lead in a factory may mean it is impractical. Have you been to a hardware store lately? A huge amount of pipe fittings for gas and non-potable water are made from lead. Factories don’t find it hard to work with lead. It might be inadvisable but it’s not hard. We can argue about the "working safely" part, but in terms of "does this make it impractical?" the answer seems to be no under the current global regulatory environment.
    - beepbopboopp 3y ago
      [flagged]
      - mlyle 3y ago
        Nah. We have a reasonable understanding of fluids. It's just that the two things we say as simple explanations (the plane pushes air downwards causing an equal and opposite reaction to push the plane up; faster flow on top of the wing "sucks the plane upwards") are both only partial truths. Sometimes you get arguments between partisans for each of these two simplified explanations, but really both are bogus.
local_issues 3y ago
Ding ding ding! We still don't know how bikes work, we have a pretty good but incomplete model for lift on airplanes, and no one has the faintest why Tylenol works. We should figure that out! But we can definitely keep using all the applications until then. (Except for Tylenol, we keep learning how bad that stuff is) EDIT: It won't let me post more, so here's the answers to responses. For sure! https://www.cbc.ca/news/science/science-of-cycling-still-mysterious-1.3699012 https://www.cbc.ca/news/science/science-of-cycling-still-mys... http://www3.eng.cam.ac.uk/~hemh1/gyrobike.htm http://www3.eng.cam.ac.uk/~hemh1/gyrobike.htm https://www.newscientist.com/article/mg22730370-400-how-does-a-bicycle-stay-upright/ https://www.newscientist.com/article/mg22730370-400-how-does... It's a fun little fact. We know a ton about BUILDING bikes, which is a more useful tool anyway
- mthomasmw 3y ago
  Do you have a link handy for "we don't know how bikes work" ?
  - prasadjoglekar 3y ago
    [flagged]
    - post-it 3y ago
      I'm not super interested in watching Joe Rogan and RFK, is there a particular bit where they talk about bikes?
      - CSMastermind 3y ago
        There's nothing about bicycles in the video he linked.
        post-it 3y ago
        A classic Freudian clip.
dllthomas 3y ago
Do we know whether the mechanism was proposed before or after observing the results? If they found the material because of the theory, then I think it's very relevant.
- beowulfey 3y ago
  Someone who speaks Korean may have to go through the original paper. It is LK-99 though; I wonder if they tried 99 other combinations first!
  - stu255 3y ago
    No, Lee and Kim first discovered the material in 1999 and have spent 20 years doing other things in between getting help to figure out how to isolate LK-99 and reproduce the correct grain structure. They eventually got a world class physical chemist, Kwon. There is now a huge bust up within the team, hence the muddled race to publish and claim credit.
    - beowulfey 3y ago
      Ahh that makes sense. I was wondering what was going on with the two papers and thought it might be something like that too. Thanks for the extra details.
- gus_massa 3y ago
  Somewhat similar compounds are superconductors, so it's possible that a wrong theory gave them a lucky hint to modify an old superconductor into the new superconductor.
ethn 3y ago
They made a synthetic a priori prediction proven by experiment. In science, that's the strongest type of claim.
- seeknotfind 3y ago
  You might also say it's the only type of claim science recognizes. Though, whatever or how strong a claim is, the question is how important is what is proven and will it lead to real superconductive materials.
- throwawaymaths 3y ago
  The strongest type of claim is when an a priori claim is called absurd, someone goes to make observations to disprove it and comes back convinced of your theory.
Terr_ 3y ago
> I don't think the actual proposed superconductivity mechanism is the relevant part of this paper. Plus even if the proposed-mechanism is incorrect and even if the effect is not strong enough for practical engineering... There's value in a "real" (if weak) superconductor which is both easy to fabricate and easy to run tests on. It could become a starting-point for dozens of other tweaked formulations, enabling all sorts of not-so-expensive experiments and fresh data about how different parameters lead to different electromagnetic outcomes.
aaron695 3y ago
[dead]
fnordpiglet 3y ago
I’m not entirely sure that’s true. A posit in the paper is this is a novel super conducting mechanism and as such if the mechanism is true it’s totally unexplored. That leaves open a huge field of new research. That’s certainly a relevant part of the paper. Super conductivity at room temperature is an amazing breakthrough alone, but if it was with a clever tweak with an existing well established technique that would be the end of the story. The fact it’s an entirely new technique opens a world unexplored and indicates a pathway to even more amazing discoveries to be had (and funding for entire generations of physicists).
- glenstein 3y ago
  Right. The mechanism itself seems extraordinary. And it seems like that mechanism is exactly the "why", the commenter is claiming is more important. Moreover, you can have more than one thing about a paper be the "relevant" thing.
glenstein 3y ago
>I don't think the actual proposed superconductivity mechanism is the relevant part of this paper. It is much easier to prove that this is superconducting than to prove why. As another commenter has pointed out, the proposal of a new mechanism seems to be extraordinary and novel, and could lead to an explosion of new research, so it does indeed seem to be "relevant" on its merits. I also don't see this as a case of the "why" being left unexplained. In the history of superconducting it has indeed been the case that new cocktails have led to superconductivity without the underlying why being understood. But the commenter that you're responding to quotes part of the paper that shows an awfully specific mechanism. I understand the sense in which there can be a "why" that remains to be explained in certain circumstances, even when you have a mechanism. Who do monarch butterflies have the black and orange pattern on their wings? There's a cause and effect answer but there's also a "why" answer. But with superconductivity, the mechanism is the why, unless I'm misunderstanding here. If other forms of superconductivity rely on other mechanisms, there isn't going to be a general why connecting this case to the other cases, but nor is there anything left unexplained just by explaining the "why" of this case by explaining it's extraordinary mechanism.

jpmattia 3y ago

> They propose that electron tunneling between these quantum wells, which are between 3.7 and 6.5 Ångstroms apart, is the superconducting mechanism. That is a very strange explanation. As someone who has done a decent amount of solid-state physics work, I would expect the explanation to involve a mechanism for pairing of electrons. Mere tunneling between quantum wells has been a staple since the "metamaterials" of the 80s and 90s. That said, the measured curves do not lie, and I haven't kept up with the field. So I'm all ears (and very much hoping the superconducting revolution is upon us!)

dexwiz 3y ago
Are you referring to a Cooper pair?
- aqme28 3y ago
  Yeah, that’s the generally used explanation for superconductivity
  - xeonmc 3y ago
    Would it be accurate to describe it as "lattice peristalsis"?
    - aqme28 3y ago
      That’s sort of the proposed mechanism for Cooper pairs forming, but I don’t think I’d call Cooper pairs themselves “lattice peristalsis”
deleted 3y ago
[deleted]

arcadi7 3y ago

Short answer: talk about quantum wells in this context is meaningless .

cma 3y ago

> sudden resistivity changes at a critical temperature (bizarrely high though that is in this case) How high? Just wondering if it might eventually be possible to use it in some power/clocking distribution layers of a semiconductor chip without bulky cooling.

jacquesm 3y ago
127C!
elihu 3y ago
That's a good idea. Honestly, I find it pretty amazing that modern CPUs don't just instantly turn into a puddle of molten metal as soon as you turn them on. The critical temperature is 127 C, as the other commenter mentioned. That seems like it's high enough to be useful in a computer CPU. I suppose there might also be applications for power distribution in a data center. You might use a few large, high-efficiency low voltage DC power supplies to supply the whole site instead of hundreds or thousands of individual power supplies if electrical resistance in cables was less of an issue. (I think this sort of thing is done now, but more at the rack level, since long cable runs cause losses.) You might even use 1V power instead of 5V or 12V. (Granted, superconducting materials don't have unlimited current capacity, and bad things happen if you exceed the limit.)
- axiomaticdoubts 3y ago
  The critical temperature is not 127 C. They did not actually measure the critical temperature. They just said it's at least 400 K (~127 C), probably because that was the maximum temperature the equipment they used could measure.
pjc50 3y ago
> Just wondering if it might eventually be possible to use it in some power/clocking distribution layers of a semiconductor chip There's an additional obstacle factor here which is that the material has to (a) be "sputterable" onto the surface, which may rule out things with fancy crystal requirements, and (b) not adversely react with the rest of the chip, which is why coppper is ruled out (!) and chips use aluminium for metal layers.

burtonator 3y ago

I want ONE breakthrough like this in my lifetime. Something completely game changing.

doctorwho42 3y ago
Live to see SPARC turn on, there are some pretty smart people with models actually showing it breaking Q>3. Turns out the hardest part about productive fusion is the sustained high compression, and HTC tape really helps increase the compression by a large amount. (See their 20 Tesla test at the start of the pandemic)
- Helmut10001 3y ago
  Just want to mention for others: The first result for SPARC on google is SPARC (Scalable Processor Architecture), whereas SPARC (tokamak) [1] is what relates to Q>3. [1]: https://en.wikipedia.org/wiki/SPARC_(tokamak) https://en.wikipedia.org/wiki/SPARC_(tokamak)
- deleted 3y ago
  [deleted]
- stu255 3y ago
  Neutron damage is the real filter for fusion.
- dgroshev 3y ago
  It would be great though if they stopped sponsoring the war in Ukraine. Yes it's unfortunate that their main HTS tape supplier is Russian, but pretending that it's not and just ignoring the issue (or obscuring the supply chain through that Japanese middleman) is pretty immoral.
- kaashif 3y ago
  Meanwhile as someone who had to deal with writing code for Solaris and using Sun's compiler, I think I've achieved my goal by seeing my last SPARC turn _off_! But yeah, nuclear fusion is cool.