Room temperature superconductor paper published

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    Paper Superconductor
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Discussion Overview

The discussion revolves around a recently published paper claiming the synthesis of a room-temperature superconductor (Tc≥400 K) at ambient pressure, specifically a modified lead-apatite structure (LK-99). Participants explore the validity of the claims, the reproducibility of the results, and the implications of the findings within the context of superconductivity research.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation
  • Meta-discussion

Main Points Raised

  • Some participants express skepticism about the paper's claims, questioning whether the results can be replicated easily, despite the simplicity of the recipes provided.
  • Concerns are raised regarding the authors' background and the quality of evidence presented in the paper, with some noting that the publication history does not strongly support experimental superconductivity.
  • Participants discuss the implications of the resistivity measurements reported in the paper, with one noting that the resistivity below the claimed critical temperature is significantly higher than that of copper.
  • There is a debate about the patentability of the material versus the process of making it, with differing opinions on the legal aspects of patent law and ownership of intellectual property.
  • Some participants highlight the potential market impact of a successful room-temperature superconductor, suggesting it could revolutionize energy transmission and create new markets.
  • Questions are raised about the definition of the critical temperature (Tc) and the lack of a sharp transition in the reported measurements, indicating uncertainty about the material's properties.

Areas of Agreement / Disagreement

Participants do not reach a consensus; multiple competing views remain regarding the validity of the claims made in the paper, the feasibility of replication, and the implications of the findings.

Contextual Notes

Limitations include the potential for undisclosed assumptions in the experimental setup, the dependence on specific definitions of superconductivity, and unresolved questions about the reproducibility of results and the clarity of the evidence presented.

Who May Find This Useful

This discussion may be of interest to researchers in superconductivity, materials science, and patent law, as well as those following advancements in energy transmission technologies.

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  • #32
DaveC426913 said:
Sounds like preliminary replication are starting to trickle in.

https://www.tomshardware.com/news/superconductor-breakthrough-replicated-twiceNot a reputable source, but I'm gonna stay tuned
Important to note, the simulation results say nothing about the ambient pressure part of the claim (other than to quote it). And the other replication mentioned in that article is the replication of the manufacturing process. Taking all of these as true, we still wouldn't have replication of the most interesting part of the claim: a high Tc superconductor at ambient pressure.
 
  • #33
DaveC426913 said:
Sounds like preliminary replication are starting to trickle in.

https://www.tomshardware.com/news/superconductor-breakthrough-replicated-twiceNot a reputable source, but I'm gonna stay tuned
Tom's Hardware is not a reputable source? How dare you!

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  • #34
BWV said:
citing this paper as replication
I do not consider a calculation, no matter how good, as experimental replication.
 
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  • #35
Wikipedia has a table

Group by group as of now:

* Diamagnetism seen, waiting for resistance measurements
* No diamagnetism, high resistance
* Big changes in resistance as function of temperature, but low or no resistance only at 110 K. No Meissner effect.
* No diamagnetism seen
* Resistance doesn't drop to zero in measured temperature range
* No diamagnetism seen
* No clear results yet

Just one group seeing diamagnetism is a bad start. Superconductivity implies (ideal) diamagnetism but the reverse is not true - even if the material is strongly diamagnetic it doesn't have to be a superconductor.
 
  • #37
Another thibg to have ib mind is that even if we find a RT SC at 1 atm, it doesn't necessailty make it useful. Not only because of the ability to make wires but also due to I max. It is said that if such a cuprate was found, it would be of little use, due to low I max. It may not lead to any technological revolution. Not sure this would be worth a nobel prize.
 
  • #38
fluidistic said:
It is said that if such a cuprate was found, it would be of little use, due to low I max.
That may be true for electrical and transport applications, but it could well be a benefit to information processing or instrumentation.
 
  • #39
Except in the dictionary, confirmation comes before application.
 
  • #40
Vanadium 50 said:
Except in the dictionary, confirmation comes before application.
I can make it consistent, by reverse sorting the dictionary, which would help to get an earlier retraction.
 
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  • #41
Here's another thing that bugs me "LK"? Really? They named it after themselves? Not only is it worth 20 points on the Baez Index, do they not remember the GFAJ-1 fiasco?
 
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  • #42
Fiasco normally comes before redaction and retraction.
 
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  • #43
I don't think the arsenic crowd ever retracted. However, I think it has been generally accepted as wrong. "Too good to check" is a common problem with such papers.
 
  • #44
Vanadium 50 said:
Here's another thing that bugs me "LK"? Really? They named it after themselves? Not only is it worth 20 points on the Baez Index, do they not remember the GFAJ-1 fiasco?
Worked (possibly) for J/Psi.
As far as I understand they picked that name as students and at a time they didn't expect that material to get larger attention.
 
  • #45
Vanadium 50 said:
This didn't happen with the last time we had the first room temperature superconductor, the Indian gold-silver amalgam. Or maybe it was the time before that.

Does this pass the smell test? It's pretty stinky. Doesn't make it wrong, but...
  1. The paper, as stated, is not very good. Doesn't make it wrong, but...
  2. The evidence plots are, at least to me, not so clear. Doesn't make it wrong, but...
  3. The authors' publication history is not in experimental superconductivity - it appears to be more in theory, and non-SC theory dominates. Doesn't make it wrong, but...
  4. The research was apparently conducted at a commercial company, This appears to be the very first paper out of this company, at least in English. Doesn't make it wrong, but...
  5. The idea of increasing the internal pressure by substitution is not new. It has had some success in the past, but nothing like this. Doesn't make it wrong, but...
  6. The authors claim to have a new family of materials. The first and thus far only member of this family has the property of interest. Doesn't make it wrong, but...
You may be sensing a theme.

Smells like... uh, ... "but" ?
 
  • #46
Is it dead or does it still just smell funny?

We successfully synthesized polycrystalline LK-99-like ceramic samples with a solid-state-sintering method. Powder X-ray diffraction shows that the main contents are Pb10−xCux(PO4)6O and Cu2S, consistent with recent reports [arXiv:2307.12037; arXiv:2308.01192]. In some small flaky fragments, we successfully observed ``half levitation'' atop a Nd2Fe14B magnet. Using magnetization measurements on such small pieces, as well as on a large piece which does not exhibit the half levitation, we show that the samples ubiquitously contain weak yet definitive soft ferromagnetic components. We argue that, together with the pronounced shape anisotropy of the small fragments, the soft ferromagnetism is sufficient to explain the observed half levitation in strong vertical magnetic fields. Our measurements do not indicate the presence of the Meissner effect, nor zero resistance, in our samples, leading us to believe that our samples do not exhibit superconductivity.

https://arxiv.org/abs/2308.03110
 
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  • #48
Is there any result that cannot be explained by this material being a diamagnetic metal?
 
  • #49
Nature: LK-99 isn’t a superconductor — how science sleuths solved the mystery
Instead, studies have shown that impurities in the material — in particular, copper sulfide — were responsible for the sharp drops in electrical resistivity and partial levitation over a magnet, which looked similar to properties exhibited by superconductors.
Multiple groups reproduced the claimed "levitation" with ferromagnetic elements and the sudden resistance drop seems to come from copper sulfide undergoing a phase transition.
 
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  • #50
University of Nottingham physicist Philip Moriarty doesn't hold back about the way this initially unfolded

 
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  • #51
Well, it sounds like we can stick a fork in it. At least until next time.
 
  • #52
Vanadium 50 said:
Well, it sounds like we can stick a fork in it. At least until next time.
But if it sticks to the fork doesn't that mean it is a superconductor?
 
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  • #55
A lot of the Dias work is...um...troubled.
 

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