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PaperclipPerfector  1yr ago (text post)   3950 thread views

Small-Scale Question Sunday for July 23, 2023

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Room-temperature and pressure superconductor discovered. It's not peer-reviewed, published, or replicated yet--what do you guys think the odds are that this is legit?

New paper from the Chinese Academy of Sciences proposes that the high-temperature steep change in resistance may have been due to Cu2S contamination. That's nice in the sense that it's a fully honest explanation -- Lee et all's original paper could be entirely measuring real things, no fraud or even measurement goofup! -- but would leave their samples as just weird rather than superconducting. There's still some space for exploration, since the XRDs from other labs pointed more to CuS2 and this doesn't explain the 110K behavior supposedly observed by the Southeast University of China, but it drastically raises likelihood of a prosaic explanation.

Thanks for keeping up with this story!

Replication of the semi-floating behavior, but (very) high (and increasing with decreasing temperature) resistance and evidence of ferromagnetism in addition to unusually high diagmagnetic behavior from a Chinese group. Their theory involves a complex scenario of ferromagnetic (maybe ferrimagnetic?) forces causing the specific half-floating behavior through torque, without much relevant impact from the large diagmagnetic components -- definitely a weird physics thing in general, and doubly so for a compound where none of the input ingredients were ferromagnetic (and many not even paramagnetic: lead, copper, and solid sulfur are all diamagnetic), but not something quite so obviously useful.

I'd be interested to see further experimentation, but it's a big impact in favor of 'weird and genuine thing, but not superconductivity' side. On the other hand, the difference between their temp vs resistance graph and most other replications is surprising : erroneous zero or near zero values are pretty common with resistance measures, but you don’t usually see entirely different slopes, which leaves open questions about contamination.

And another claimed semi-replication by randos, supposedly using a different approach and getting their sample entirely floating off the surface. It still looks a little different than most flux pinning examples I can find, but going to need either someone to scale up meaningful production sizes, or a more specialized lab looking at other traits used to identify superconductivity.

First publicly claimed partial replication of magnetic weirdness in America. Very small size compared to the input materials, and seems weirdly shiny compared to a lot of other attempts, which points to at least a difference in manufacturing.

There are still non-superconducting explanations -- the magnetic measurements could be 'just' extremely strong diamagnetism, and even the efforts to attempt resistivity and critical current measurements from other groups have not been amazing so far. But it at least drastically reduces the odds that this is a simple fraud.

There have also been some interesting failures to replicate.

A claimed Chinese replication including superconductivity... to 110K. Not outside of the realm of other past ambient-temp high-temperature superconductors (though higher than YBCO). This could plausibly represent manufacturing faults lowering max temp, or measurement faults giving false reads of superconductivity

If true. Also starting to see more jokes or grifts.

A claimed Chinese replication at very small scale and low purity showing reaction to magnet, some fascinating theoretical approximations that have give a weakly plausible theory, albeit with many limitations, and a number of failed replication attempts. Manifold's floating 40%+ for replication by 2025; I'm a little more skeptical than that, still, but I'm not sure I'm skeptical enough to sell at those prices.

And a guardedly-optimistic summary from Derek Lowe.

Funnest update of the week so far: lesbian Russian catgirl replication in an apartment, with a pile of scraps. I've no idea how to guess whether this is real or not, but either way it is hilarious.

Yeah I saw that one hahaha. Such a tiny speck floating, it could easily have just been clinging to the needle or something, but I definitely want to believe. If it's a real superconductor, 1) stuff like that should be possible, but 2) why are they not just experimenting using the original materials? Replication (at least, validation of the claims) should be easy with the actual material on hand.

The original protocol is trivial by superconductor (or even semiconductor!) research standards, but it's still filled with a number of individual materials that are expensive, controlled, or absolutely aren't safe to run in an apartment, along with a couple steps that require a long time with uncommon tooling. Iris_IGB's proposed approach cuts out some nasty chemicals and nearly half of the synthesis time; she probably just wouldn't have tried the original protocol at all.

Of course, optimizations only help if it works...

Of course. What I meant was, why not test the original material which the original researchers have already created? I'm dying to get some external validation and true replication could take months/years.

Not sure what's going on at that level. Most people seem convinced that the South Korean lab must be sending out samples for testing, or at least talking in person with MIT-level experts, but outside of saying that it's planned I've not seen much. The sorta people who have big XRD toolkits don't tend to spend too much time speculating on twitter, though.

I'm not reading all that lol (actually I don't know jack about shit when it comes to pixies, it's all magic to me once people start talking about ohms. I'll wait for someone I know with a full fat engineering degree to offer an opinion)

For real though: Those are Korean names and I know they do a decent amount of boring hard physical research there, so I'm upgrading my +-1% prediction to a slightly stronger +-1%.

EDIT: SHIT FUCK SHIT someone who knows about pixies thinks it might be real (15-20%) noooooo my fake internet Nostradamus points

30% that it's legit but a dead end in the sense that this whole line precludes higher currents, 60% that it's outright a fraud or some error motivated by wishful thinking, 10% that this is the beginning of a successful line that ends in viable high-temp superconductors in <20 years.

They have a website, a partially-linked and far more professional looking second paper, and a this video, and this less janky one. It's not obviously cranks coming out of the woodwork.

The Hirsch-Diaz feud and grifting's primed me to expect a lot of process-level-jank at best whenever new claims of high-temperature superconductivity come about, but this looks like it would either have to be incredibly overt fraud, the real thing, or some new electromagnetic behavior that would itself be very noteworthy if not as big a deal (eg, unusually high diamagnetic forces for a lead-copper compound, or even compared to graphites). You get a lot of current and resistance measurement problems with thin films, but the magnetic behavior is something different.

The biggest wierdness is how extremely simple the synthesis is. This isn't the first 'supermaterial' I've seen with the sort of production process that would be too easy for the Applied Science guy, but even if the process is picky as fuck and the yield tiny, these guys have a problem. If it's a fraud, a ton of materials labs will have disproved it by the weekend; if it's not, they're got patents on a material that are going to be Very Interesting to enforce. And not just for the 'you and what army' problems: if this approach works I don't see any clear reasons it'd be the only one.

EDIT: I'm seeing play-money bets around 15-30%, and I'd probably put some petty cash on the higher range, maybe 20-25% real, ~20% intentional fraud, remainder some incredibly specific measurement error or new weird thing. Which probably sounds a little pessimistic, but given how fucky this field's big names are, that's relatively impressed. The corporate stuff is still sketchy, though, and they're looking at indirect-enough measurements that "just amazingly diamagnetic" is definitely an option.

EDIT2: Even if true, I will note that all the critical currents are low so far. May be a production artifact, but if insurmountable would prevent some useful applications, especially if it can't scale up or can't scale up at reasonable costs. Still would be important.

EDIT3: Looks like they have one paper published in a (tiny) peer-reviewed journal on this already, albeit primarily in Korean and looking at lower-if-still-roomish-temps. I've got a low enough opinion on peer review that I don't think it changes much. Sorta thing you might do if trying to bilk naive investors as much as if serious.

Patent-wise, they seem to make some pretty broad claims:

A method for producing a superconducting ceramic compound comprising a step of synthesizing a ceramic compound according to Chemical Formula 1 by depositing a raw material.

A a B b (EO 4 ) c X d

A: (s-, p-block metals) Ca, Ba, Sr, Sn, Pb (lanthanides, etc.) Y, La, Ce or combinations thereof

B: (d-block metal) Cu, Cd, Zn, Mn, Fe, Ni, Ag or a combination thereof

E: P, As, V, Si, B, S or a combination thereof

X: F, Cl, OH, O, S, Se, Te or a combination thereof (a: 0 to 10, b: 0 to 10, c: 0 to 6, d: 0 to 4)

If this is actually real, it seems to cover most related candidate materials. Though of course there might be some alternative method to synthesize it.

If this turns out to be true it will be hilarious, I mean the first room temperature super conductor is an easy to synthesize material discovered by some Korean academics no one had ever heard of before! I mean their website isn’t even working right now.

Oh, yeah, there's absolutely a ton of hilarious stuff going on, including some drama. I'm still pessimistic, but the perversity of the universe trending to a maximum might even work in its favor, here.

Thanks, that's amazingly informative.

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