5 ms·

Interesting. Some people are getting strong diamagnetism at RTP, and now someone is actually seeing zero resistance at a low temperature. I'd take this as mild

Interesting. Some people are getting strong diamagnetism at RTP, and now someone is actually seeing zero resistance at a low temperature. I'd take this as mildly positive news. It would be a surprising material if it were a high Tc (only in the LN2 sense) superconductor that is also strongly diamagnetic at room temperature (though I'm not sure if that's more surprising than a RTP superconductor).

jacquesm 3y ago
It's confusing. You'd expect both to be present or none, it is strange to have a material that is conducting and diamagnetic at room temperature and that shows super conductivity at much lower temperature. You'd expect the diamagnetism to disappear with the superconductivity.
- marshray 3y ago
  Multiple teams have said they had to produce 10 batches just to get one sample with properties worth reporting on. Perhaps the simplest explanation is that different teams are all ending up with different variations of a common material, with different impurities, crystal structure, etc. There's likely a whole zoo of interesting materials here!
  - jacquesm 3y ago
    Yes, I thought that that might be the case from day one. When they wrote that they had only a 10% success rate it was clear that they were not at all in control of sample purity. The big remaining question for me is what happens when they start traveling with the original sample to have another lab test their samples and how those results compare with both the original results and the independently recreated different samples. There is a good chance that there will be substantial differences between them.
    - dv_dt 3y ago
      “Purity” is a really overloaded term here. There are vast set of material properties that simply don’t map to a definition “purity” as in some homogeneous concentration of a material. This is so early no one likely knows exactly what configuration of material to “purify” for the intended outcome. There will likely be years of not decades of looking at differences in the materials and performance of related materials to more fully explore this discovery.
      - jacquesm 3y ago
        Yes, true, let me unpack that then: - purity as in the sample is uniformly constructed of the right atoms but they are not in the right configuration vs - purity as in the sample contains atoms that shouldn't be there in the first place and finally - purity as in: the sample that purportedly did show room temperature superconductivity turns out to be the impure one and that impurity is so poorly understood that we currently can not replicate it accurately, but a test by an independent lab of the sample would verify the properties as advertised. All of these are possibles, and not mutually exclusive.
        trafficante 3y ago
        > purity as in the sample is uniformly constructed of the right atoms but they are not in the right configuration The conclusions in the linked pdf suggest this may be the issue with LK99. 1. https://arxiv.org/abs/2307.16892 https://arxiv.org/abs/2307.16892
  - borkt 3y ago
    More than likely there is only one interesting material in this specific composition. But understanding the phenomenon we are observing in this material can potentially lead to the development of other materials which display these characteristics, and tune those to function in this way at specific temperature/pressure situations. If we develop efficient ways to produce these materials in bulk (which is orders of magnitude more complicated than just characterizing what we see here) it would be unimaginably revolutionary. But the energy required to do this at scale will likely require our civilization to utilize orders of magnitude more energy, so if this is practical for our daily lives on a wide scale I believe it's development will be contingent on harnessing fusion. Otherwise it will be limited to only the most extreme use cases in the way superconductors are currently used now.
    - AS04 3y ago
      My friend, what exactly do you think is so energy intensive with LK99 synthesis? I've briefly taken a look and the process proposed is really not that onerous in terms of energy consumed. It is a matter of perfecting the process that is the hurdle, we already spend tons of energy happily in similar industrial processes.
    - jacquesm 3y ago
      > But the energy required to do this at scale will likely require our civilization to utilize orders of magnitude more energy As opposed to smelting aluminum or steel? And that creates stuff that is dirt cheap in bulk...
- borkt 3y ago
  Observed effects which have been given a name != a single universal truth. Just because we have experimental evidence of effects and theoretical explanations for their occurrence prove we actually have defined the underlying phenomenon's which produce the observed effect accurately. The reason we experiment isn't to prove our theories are correct so much as it is to probe where they break down so we can further refine our understanding of the universe. What we are likely seeing here is the result of an organized pattern of atomic nucleii forming a lattice which creates the conditions for the movement of electrons to be easier (or harder) than expected at certain temperatures (with temperature being the property which induces strain on the lattice). This is very crude, but begins to explain the multitude of factors at play here.
  - jacquesm 3y ago
    Yes, that's true, but that would require a shift in our understanding of physics and everything about this saga so far has not done that. And that in part is a reason why people take this serious: it is believable. New physics would raise the bar considerably. So for now I'm on the measuring error, impurity or process issue side of that without committing to which team I think has the problematic side.
    - borkt 3y ago
      The fact that our existing computational models are in agreement with the experimental behavior leads me to believe there is no new physics involved here. That being said this raises the question as to whether this class of material is known and characterized within our national research labs but has been kept classified, and if it was unknown it raises the question of why experimentation is what discovered it and why weren't we able to harness the computational model to identify it theoretically and develop a method to produce it practically prior to this. My money says there are people in this world who have long been aware of this, and its either already in use in a classified manner or it's interesting but there are other materials which are more practical in all use cases.
      - jacquesm 3y ago
threatripper 3y ago
If only part of the sample is superconducting and the other parts are ordinary conductors or isolators, the superconducting islands could show diamagnetism while being isolated from each other which means that eletrical current needs to pass resistive areas and therefore experiences resistance.
- valianteffort 3y ago
  Could it not also mean an impure sample? Everyone is in a rush right now but none of these research teams are exactly experts of manufacture.

jacquesm 3y ago

It's confusing. You'd expect both to be present or none, it is strange to have a material that is conducting and diamagnetic at room temperature and that shows super conductivity at much lower temperature. You'd expect the diamagnetism to disappear with the superconductivity.

marshray 3y ago
Multiple teams have said they had to produce 10 batches just to get one sample with properties worth reporting on. Perhaps the simplest explanation is that different teams are all ending up with different variations of a common material, with different impurities, crystal structure, etc. There's likely a whole zoo of interesting materials here!
- jacquesm 3y ago
  Yes, I thought that that might be the case from day one. When they wrote that they had only a 10% success rate it was clear that they were not at all in control of sample purity. The big remaining question for me is what happens when they start traveling with the original sample to have another lab test their samples and how those results compare with both the original results and the independently recreated different samples. There is a good chance that there will be substantial differences between them.
  - dv_dt 3y ago
    “Purity” is a really overloaded term here. There are vast set of material properties that simply don’t map to a definition “purity” as in some homogeneous concentration of a material. This is so early no one likely knows exactly what configuration of material to “purify” for the intended outcome. There will likely be years of not decades of looking at differences in the materials and performance of related materials to more fully explore this discovery.
    - jacquesm 3y ago
      Yes, true, let me unpack that then: - purity as in the sample is uniformly constructed of the right atoms but they are not in the right configuration vs - purity as in the sample contains atoms that shouldn't be there in the first place and finally - purity as in: the sample that purportedly did show room temperature superconductivity turns out to be the impure one and that impurity is so poorly understood that we currently can not replicate it accurately, but a test by an independent lab of the sample would verify the properties as advertised. All of these are possibles, and not mutually exclusive.
      - trafficante 3y ago
        > purity as in the sample is uniformly constructed of the right atoms but they are not in the right configuration The conclusions in the linked pdf suggest this may be the issue with LK99. 1. https://arxiv.org/abs/2307.16892 https://arxiv.org/abs/2307.16892
- borkt 3y ago
  More than likely there is only one interesting material in this specific composition. But understanding the phenomenon we are observing in this material can potentially lead to the development of other materials which display these characteristics, and tune those to function in this way at specific temperature/pressure situations. If we develop efficient ways to produce these materials in bulk (which is orders of magnitude more complicated than just characterizing what we see here) it would be unimaginably revolutionary. But the energy required to do this at scale will likely require our civilization to utilize orders of magnitude more energy, so if this is practical for our daily lives on a wide scale I believe it's development will be contingent on harnessing fusion. Otherwise it will be limited to only the most extreme use cases in the way superconductors are currently used now.
  - AS04 3y ago
    My friend, what exactly do you think is so energy intensive with LK99 synthesis? I've briefly taken a look and the process proposed is really not that onerous in terms of energy consumed. It is a matter of perfecting the process that is the hurdle, we already spend tons of energy happily in similar industrial processes.
  - jacquesm 3y ago
    > But the energy required to do this at scale will likely require our civilization to utilize orders of magnitude more energy As opposed to smelting aluminum or steel? And that creates stuff that is dirt cheap in bulk...
borkt 3y ago
Observed effects which have been given a name != a single universal truth. Just because we have experimental evidence of effects and theoretical explanations for their occurrence prove we actually have defined the underlying phenomenon's which produce the observed effect accurately. The reason we experiment isn't to prove our theories are correct so much as it is to probe where they break down so we can further refine our understanding of the universe. What we are likely seeing here is the result of an organized pattern of atomic nucleii forming a lattice which creates the conditions for the movement of electrons to be easier (or harder) than expected at certain temperatures (with temperature being the property which induces strain on the lattice). This is very crude, but begins to explain the multitude of factors at play here.
- jacquesm 3y ago
  Yes, that's true, but that would require a shift in our understanding of physics and everything about this saga so far has not done that. And that in part is a reason why people take this serious: it is believable. New physics would raise the bar considerably. So for now I'm on the measuring error, impurity or process issue side of that without committing to which team I think has the problematic side.
  - borkt 3y ago
    The fact that our existing computational models are in agreement with the experimental behavior leads me to believe there is no new physics involved here. That being said this raises the question as to whether this class of material is known and characterized within our national research labs but has been kept classified, and if it was unknown it raises the question of why experimentation is what discovered it and why weren't we able to harness the computational model to identify it theoretically and develop a method to produce it practically prior to this. My money says there are people in this world who have long been aware of this, and its either already in use in a classified manner or it's interesting but there are other materials which are more practical in all use cases.
    - jacquesm 3y ago

threatripper 3y ago

If only part of the sample is superconducting and the other parts are ordinary conductors or isolators, the superconducting islands could show diamagnetism while being isolated from each other which means that eletrical current needs to pass resistive areas and therefore experiences resistance.

valianteffort 3y ago
Could it not also mean an impure sample? Everyone is in a rush right now but none of these research teams are exactly experts of manufacture.