Global Room-Temperature Superconductivity in Graphite | Hacker News Reader

Global Room-Temperature Superconductivity in Graphite

onlinelibrary.wiley.com

121 pointsdanboarder29 comments

Building on previously reported local superconductivity in graphite, have provided much explanation to why this occurs, has been in review for over a year, no signs of trying to sell a product, and provides guidance for further material research...

> In the present work, we report the first unambiguous experimental evidence for the global zero-resistance state, RTSC, in the scotch-tape cleaved highly oriented pyrolytic graphite (HOPG) that possesses dense arrays of nearly parallel line defects (LD), the wrinkles...

> The basic principle we have uncovered is that linear defects in stacked materials host strong strain gradient fluctuations, which induce the local pairing of electrons into condensate droplets that form JJA-like structures in the planes.

Very neat!

Care to translate it? It's a wall of lingo for me.

For now, this is very interesting, but it still does not exist any obvious path for using this effect in a practical device.

Because superconductivity is not a property of the normal structure of graphite, but it appears when a certain configuration of defects is formed by breaking the graphite, I assume that it is difficult to obtain twice the same properties.

Moreover, because superconductivity appears in a fragile crystal, it could not be used for flexible cables, but only for rigid PCBs or inside integrated circuits. Because the superconductivity is on the surface of the crystal, not in its volume, it will not be able to carry high currents.

Nevertheless, it is likely that after some years the reproducibility problems could be overcome.

Neither superconducting graphite nor lead apatite appear promising for high-power applications, but one of them or a similar material could lead to significant improvements in integrated circuits and PCBs.

This research seems predominantly focused on explaining the actual mechanism by which RTSC can be achieved, and a demonstration of it. Understanding the "why" is the best part, as it allows us to begin intentionally designing ways to force these wrinkle impurities onto not only this material, but others.

Compared to modern chip manufacturing processes, cleaving and stacking pyrolitic graphite in a controlled way seems quite doable. I'd like to be optimistic, at least!

A ceramic, relatively fragile superconductor can be powdered and embedded in a flexible material, like a polymer, and retain superconducting properties. You see this in use currently with relatively high temperature superconductors, where flexible cables are able to be produced. As long as you have unbroken chain of connections from end to end, in some material the orientation doesn't matter, you just need tiny little bits that are touching eachother sufficient to make an electrical path.

Other materials, like glass, oils, metals, liquids, can serve as an embedded substrate, which can then be encapsulated by a flexible surface material. LK-99, with as much lead content as it had, would be difficult in terms of consumer safety, but graphite is trivial. If you could produce a sufficient quantity of superconducting particles to embed in polymer, then insulate cord, tape, or other flexible form factors, you wouldn't have to worry to much about disposal and recycling. LK-99 would be a possible toxic addition and probably not great for the world, even with superconducting features, in a public commercial context.

I can try an ELI5: We have previously seen that a form of graphite with impurities demonstrates superconductive behaviors to some degree at very tiny, inconsistent scales. They came up with an idea on the physics of why this happens to this material and have managed to intentionally reproduce the effects at a larger scale where we can say this is a genuine property of the material and not a weird localized effect on a tiny fraction of it in certain conditions.

The best I can explain the actual physics would be that some interactions at the impurities cause electrons to form "wires" of superconductivity in one axis across them. This isn't unheard of in existing materials, but the problem is that in those materials they tend to be isolated "wires" and even tiny disturbances throw the whole thing off.

But that in this material, the way these impurities forms creates a mesh of these "wires" where charge/magnetism can jump. Subsequently, it's resistance to disturbances climbs dramatically, as alternative superconductive paths can be taken as any disturbance propogates through a given part of the material.

They now believe we can use this knowledge to intentionally construct even more materials with this behavior.

And because I never stop finding it hilarious... Part of the preparation of the material is repeatedly taking a piece of scotch tape to a thin strip of the graphite, removing the top layer to make it extra thin.

The parts of my comment that are not quotes are just reasons to not immediately dismiss it, like many other "keystone" technology discoveries.

The scotch tape bit is fun. You can apparently strip atom thick layers of things with scotch tape, and also generate x-rays with it.

https://www.technologyreview.com/2008/10/23/217918/x-rays-ma...

Isn't that also how Graphene is made?

Graphene is made in various ways, ranging from scotch tape (relatively large crystals), to ultrasonic dispersion of graphite in water and soap (tiny microscopic flakes) to vapor deposition for large films, and all sorts of other variations of those themes depending on what you want. Flakes are trivially produced and are starting to be used as additives for desirable structural, electrical, and chemical effects.

Graphene was initially created using scotch tape, however, and it remains a reliable and simple method of getting high quality graphene for lab experiments.

For those coming to the comments first, this is at standard pressure as well.

Does standard pressure mean "sea level", or does it have its own special meaning like "high-temperature superconductor" to indicate "works above -200C"?

1 atm tested up to 300K (26.5C / 80F).

What is "global" in this context? I assume it means throughout the entire material sample, as opposed to some small section of it?

Yep - best explanation is from the introduction:

> Various experimental groups have also reported localized superconductivity in graphite at temperatures as high as 300 K. [...] However, so far, all the efforts to achieve a global superconductivity at elevated temperatures in graphite failed.

I mean AI is helping to discover new molecules, predicting protein folds, etc. Pretty sure it must already be being used to discover new materials as well, hopefully we can throw this sort of thing at it today/in the near future, too.

Humanity as the seed of an idea/initial research and AI as the army of low-level "researchers" running billions of experiments/analysis; stuff that would take way too many human-years/would be boring as hell for a human to do.

Here we go again

Hopefully this time it can be confirmed

For what it's worth, LK-99 adjacent research is still happening[0].

[0](https://arxiv.org/abs/2401.00999).

It's probably an important thread to follow in any case

It's the boy who cried room temperature superconductivity effect. If we in fact live in a simulation I can clearly see that when someone in fact achieves RTSC, nobody will believe it at first. It's the most movie like turn of events, just as a good simulation writer would like to see.

Believe is something religious people do. The great thing about science is belief is unnecessary. If someone makes a fantastic claim it is reasonable to be skeptical. Skepticism is not an obstacle when you can prove that your claim is true.

The proof in the pudding is in the tasting.

> Believe is something religious people do. The great thing about science is belief is unnecessary.

Unfortunately, we are not all equipped to replicate all experiments, so even scientists rely on a significant amount of belief and faith.

No. We do rely on trust. I'm not saying everyone needs to replicate all experiments.

This is trivial. If this superconductor is real then people will replicate it. People will publish results and once we have multiple independent verifications we can trust that it's real.

If it is also practically applicable then it will start to be used in real appliances and when we see it working we know it's real.

Science is frequently wrong. False positives, fabricated results etc are published on a daily basis. We should not accept one study's results as fact, we should not blindly believe in it, that's not how science works. We should understand that there are degrees of trust and certainty. A qualitative study is highly unreliable, a quantitative study's reliability depends on specific details such as sample size, methodology etc.

All a study says is "we did this and saw these results". We don't know that it isn't fabricated, we don't know that the description is accurate, we have to take it with a grain of salt. But at some point we have enough data to trust claims like "this medication is effective at treating this illness" or "this material is superconductive at room temperature".

Right, but that trust comes from somewhere. I don't check the credentials of the authors on every paper I read, nor demand professors show me all effect experimentally. We rely on our networks to assign trust appropriately, but often we don't even verify that! We're forced to take so much at each others word that the system may as well be predicated on our faith in humanity. You can see this go wrong as well, people who've lost a little faith start doubting more and more experimental evidence, particularly that which falls outside of their beliefs.

I don't mean the system's broken in any way, far from it, this is a healthy functional system of scientific discovery! I just think it's fascinating how much is predicated on good faith.

Eh, I would count myself among those doubting a lot of experimental evidence. There is a lot of bad science around, and even good science is frequently used to draw incorrect conclusions. If everyone uses 95% confidence as the standard then 5% are wrong. That's one in twenty, and that's the best case scenario. In reality there is a lot more that goes wrong, and there's a lot of people out there who don't give a shit about things like integrity. And it's not like all scientists are perfect geniuses, people make mistakes.

There's also a lot of things that do get disproved, but nobody ever hears about that. Journals generally publish positive results, they don't publish negative results or failed replications. The whole for-profit scientific journal system seems pretty messed up to me.

But this is what we have. So I think it's important that people understand the limitations of modern science. In many cases the science is solid - we know MRI machines work, they're used all over the world. So clearly the science behind them is solid. It gets more fuzzy when people publish studies like "People who eat dark chocolate get cancer less frequently" because I can guarantee you any study in that vein will have something like a 4% lower incidence of cancer in the chocolate group than the control but it'll technically be just above the arbitrary limit we use to determine statistical significance.

That's the kind of science I consider pointless bullshit. It's not enough to be statistically significant, it has to be solid. It has to show a clear and indisputable effect, if it doesn't then the study is pointless. "It is possible that eating dark chocolate has some positive effect on your odds of getting cancer" is a completely useless result. We knew that before you started the fucking study.

Belief is something nearly everybody does, religious or not: when I go downstairs to make some tea, I act thus believing that there is tea downstairs; when I reason by modus ponens, I do so believing therein; and when a scientist uses a theorem in a derivation, they will often believe that the result is going to be at least approximately correct in some sense to be specified thereof.

Beliefs of course vary in the level of justification (a) that can be supplied (b) that actually is present.

No one should believe it at first. That's how we get progress. If everyone believes fantastic claims too fast, we will just have frauds and mistakes everywhere.

See: merits of blockchain

That made zero sense

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