The first experimental support for LK99-type superconductivity | Hacker News Reader

The first experimental support for LK99-type superconductivity

arxiv.org

128 pointsdeyiao45 comments

“We therefore appoint the most possible mechanism to the superconducting vortices. The low-field absorption of microwave power with the assistance of dc magnetic field points to the small superconducting gap, and the relevant metastable excited states emerge to be vortices.”

It remains to be seen if this is a misunderstood experiment or a new discovery. Regardless, this is science operating as it should with people sharing the data that they have. But no need for the general public to speculate aimlessly.

This whole situation reminds me of the EMDrive. There was huge excitement when the news broke of a claimed way to produce momentum without expelling mass. That excitement was only intensified when NASA agreed to test one of the proposed designs. Even after multiple reproducible experiments showed zero thrust a vocal minority still believed.

This isn't exactly like that since the results are slightly less conclusive at this point. But the excitement without reproducible data is definitely there.

https://en.wikipedia.org/wiki/EmDrive

Not quite as messy as the ecat:

https://en.wikipedia.org/wiki/Energy_Catalyzer

As I understand, neither EmDrive nor E-Cat could be reproduced by any third party. This paper is a third party reproduction, so it seems pretty different.

Unrelated to EmDrive, but similar... is the thruster based on the theory of Quantized Inertia[0]... it passed multiple lab tests on the ground, and is now in orbit[1,2], waiting for the other experiments in the satellite to be completed before they power it up. If it works as expected, they'll be boosting the orbit of the satellite by 100km without using propellant, thanks to a 1 milliNewton electric thruster pushing on its mass of 4.8 Kg.

[0] https://quantizedinertia.com/

[1] https://db.satnogs.org/satellite/QDDY-8878-5291-1819-3935#ma...

[2] https://celestrak.org/NORAD/elements/graph-orbit-data.php?CA...

Oops.... #2 should be 58338 (wrong object #)

https://celestrak.org/NORAD/elements/graph-orbit-data.php?CA...

Evidence of superconductivity in LK99 materials, presented by a Chinese team, is presumably the first experimental support for LK99-type superconductivity. The paper lacks evidence of zero resistance, attributed to the presence of only a small amount of superconducting material, "the long-standing vortex state can only be thought of stemming from superconductivity." However, numerous modifications made to their material make it difficult to still refer to it as LK99.

What modifications? About the only thing they write about synthesis in this paper is "We follow the procedure of Lee et al. to synthesize our CSLA samples, with 1:1 mole ratio of Pb2(SO4)O and Cu3P", which doesn't show any modifications.

A corresponding author (Yao Yao) wrote an explainer of the paper, which you should read together. The paper itself is pretty cryptic.

https://www.zhihu.com/question/635259000/answer/3330698364

Since the explainer is pretty long (but it is much more fun to read than the paper, because it is written for the lay people and the paper for experts), here is a sample. It is a description of discovery of memory effect referred to in the title of the paper.

那天第一次转完样品信号消失, 我几乎一夜未眠, 惴惴不安地想知道第二天它到底能不能恢复. 直到第二天亲眼看到信号再次出现的时候, 你们能体会那种看到了未来的心情吧?

That day, after the first sample was processed and the signal disappeared, I was almost sleepless the entire night, anxiously wondering whether it would recover the next day. It wasn't until the next day, when I personally witnessed the signal reappearing, that you could understand the feeling of having seen the future, right?

anecdote: authors seems to be active posting on Chinese Tiktok, by the alias of 牛剑渣 ("Newton's Blazing Laser Sword" and "Guy of Debris/Douchebag")

That's Jicheng Liu, the first author of this paper, and a different person.

Before restarting this whole controversy it's probably best to wait for some independent confirmation.

Eh, this is an independent confirmation (from Chinese team, of Korean team).

To be clear, I'm not disparaging the work here - I'm not qualified in the slightest to evaluate it one way or the other. All I know is that the bar for a second ongoing internet drama needs to be higher than it was the first time. If it turns out to be real, that would be great, and we'll certainly hear a lot more about it.

(while nail biting)...we are back?

If you were from the future and needed a scientific discovery to be made sooner than it was originally, how do you spur the discovery without giving up the fact that the info is from the future? How to make the discovery look totally natural without being artificially juiced? You drop an apple on someone's head? What do you do when the juicing was too simple and it was missed? You try it again until someone gets it with a different group.

If room temperature superconductors are a thing does this mean there's a ringworld out there somewhere?

&& when do the Kzinti show up?

I haven't gotten to that chapter in the book yet

FYI 604 is a really great album by this band Ladytron

Problem is that the only thing scrith can possibly be is strange matter. That's a big advance in material science.........

It could be conventional matter in the island of stability [1].

[1] https://en.m.wikipedia.org/wiki/Island_of_stability

round 2 of pro- and anti- conductors annihilating each other

as pro is to profusion, con is to confusion

I thought this saga ended already?

Yes, especially since this paper was published following the Korean Validation Committee's statement on the 13th, which did not support LK-99. However, the Chinese team's experimental data is quite substantial, and the material they synthesized is also difficult to classify as LK99.

There's so much academic fraud in Chinese labs, this paper is worthless.

I don't think this is a fair comment. Relative to both its population and its economic size, Chinese articles are over-represented in prestigious peer-reviewed journal publications (think Nature and Science).

Do some trash articles out of china find their way into journals? Yes. But if you think the US/EU doesn't put out some garbage as well, I can tell you're not in academia.

Is this specific paper worth anything? I don't know. But I do know it's entirely unfair to simply write off an entire country out of hand.

"Is this specific paper worth anything?"

Yes! Simply because someone will have to either validate its findings or show that they're incorrect.

Also, you're right about the comment being unfair. Diamonds are often found amongst much dross and rubble.

Any bold statements made that can't be supported will quickly be shot down by other teams. So long as they've been transparent enough about their methodology others can try replicate their results. You don't have to like China or w/e for Chinese research to be valid.

It was only Season 1.

Right. Something's going on, further seasons will determine what. Fingers crossed.

Did the Soviet catgirl sign up for the next season?

Unknown! I'm eagerly awaiting….

At least she immediately commented on this paper. https://twitter.com/iris_IGB/status/1736947651126415426

This sample was (very) different from the original LK99.

Why do you think this?

Fool me once...

<title>Strange memory effect of low-field microwave absorption in copper-substituted lead apatite</title>

:| editorialized titles are click bait.

tldr; material has some strange characteristics. It's not superconducting.

In current theories, superconductivity is the only reasonable explanation for these strange characteristics.

That is not the conclusion they drew in their paper.

They were more modest in their conclusions, and plan to do additional work to continue to investigate it.

We back?!

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