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Electronic Structure of LK-99

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Re: Electronic Structure of LK-99

#321

Post by opticfluorine »

semajian wrote: post #100
tnecniv wrote: post #85

Earlier quoted context omitted.

I’d be interested in seeing a source on that. My understanding was that it was a powerful and popular computational tool. The theory is approximate but approximate theories can still be quite useful if the approximation is a good one.

It's basically an open secret, no one really believes DFT has much predictive power in strongly correlated systems (where relevant electrons cannot be treated as independent). It's not useless, but DFT calculations require many arbitrary choices and are hardly "first principles" in a meaningful way.

The LBNL DFT paper isn't claiming to have modeled the strong correlations. Rather, they observe a specific feature of the band structure (flat bands crossing the Fermi level formed from d-orbitals) that have also appeared in DFT calculations of other high-temp superconductors and are considered a signature of those materials. In the other high-Tc materials, the calculations are consistent with experiment, and so the unexpected appearance of these bands in the reported crystal structure is seen as a signal of "hey, if this turns out to be real, we can explain it with current physics." That's something that previous fraudulent claims of room temperature ambient pressure superconductors (University of Rochester group) couldn't do.

The other interesting conclusion of the LBNL paper is that the low-energy physics of the electronic structure can be effectively modeled by a two-level effective Hamiltonian. This is a common pathway to bridging the gap between DFT calculations and theoretical understanding of strong correlations.

None of the serious scientists are saying "hey, look, DFT predicted it so it's true." Rather, it doesn't rule it out, and it suggests that it could be understood with our current physics. That's significant in itself.

Re: Electronic Structure of LK-99

#322

Post by mewpmewp2 »

fragmede wrote: post #234
serf wrote: post #170

Earlier quoted context omitted.

> I despise generative LLMs and avoid using them at every opportunity. why? it's just a tool. despise how it was released, how it was trained, the people that operate it , whatever, but I can't really understand why someone would 'despise' a wrench -- even if it was used really poorly and produced by a shady company with a checkered past.

Same concept as blood money. To be dramatic, if the wrench was made with ore from a mine where your father worked, and he was killed and the ore was stolen, would you do business with the company that hired the mercenaries that killed him? Would you buy a wrench from them? if one fell into your hands, would you use it? It's just a wrench, after all, but you can see why somebody might have strong feelings about it, ev…

Most tech throughout history was built during wars and rough circumstances. With this mindset almost nothing should be used.

Re: Electronic Structure of LK-99

#323

Post by TheBigSalad »

lt wrote: post #76
dralley wrote: post #30

My understanding is that the "99" in LK-99 is the year it they first synthesized the material, i.e. 1999. Assuming this is all true, why is it just now coming to light? Did they just not know what they had? (I have not been following this closely, maybe this has already been explained)

As I've read it, the first lead to the material was 99. 2018 They got funding to research it further, 2020 was a first attempt of publication at Nature that was retracted, further improvements were made until 22/23 were two patents were filled, then suddenly 10 days ago Kwon, one of the co-researchers jumped the gun publishing a paper with the details, on one hand fearing a leak of someone else publishing first as th…

So... He leaked and claimed it was because he feared someone else would do it before him?

Re: Electronic Structure of LK-99

#324

Post by itsoktocry »

jacquesm wrote: post #209
jeffbee wrote: post #16

The most interesting phenomenon revealed so far is that the room-temperature superconductor people and the generative-LLMs-are-God people draw on the same limited global pool of credulity, such that HN cannot be flooded with both ChatGPT worship and superconductor speculation at the same time.

Jeffbee in the 1947 edition: The most interesting phenomenon revealed so far is that the solid state electronics people and the rocket fanatics people draw on the same limited global pool of credulity, such that TinkererNews cannot be flooded with both transistor worship and moon travel speculation at the same time. Seriously: if it doesn't interest you, you could simply refrain from commenting and even reading. This…

>Similar trends can be observed rectro-actively for practical solar panels, micro electronics, powered flight and so on. All had their skeptics

Isn't this textbook survivorship bias?

On the grand scale, I bet the skeptics have a much better record than the optimists.

Re: Electronic Structure of LK-99

#325

Post by naasking »

feoren wrote: post #276
swalsh wrote: post #95

Earlier quoted context omitted.

It's so hard not to be crazy excited about the future. The past few months are proving to be an absolute breakout for the literal human race. So far we've seen: 1. in Dec 2022 We saw a fusion breakthrough seeing a net gain in energy 2. In March GPT-4 was released, which seems to be a seminal breakthrough in AI, and maybe of our first glimpse in what could become an AGI. 3. In May we find out apparently our government…

From my perspective, LK-99 is by far the most likely to be an actual serious technological breakthrough. If it's real, it would be a breakthrough on the level of the discovery of electricity, the lens, the transistor, or the laser. One of those era-defining bottlenecks in the Civilization technology tree. GPT-4 is a nice iterative improvement over previous work, and a culmination of decades of research. It's not anyw…

> It's not anywhere near an AGI

Conjecture. We literally have no idea how far away from AGI we are, that's one of the dangers.

Re: Electronic Structure of LK-99

#326

Post by orangepurple »

cooper_ganglia wrote: post #120
tnecniv wrote: post #83

Earlier quoted context omitted.

I identify with that. It didn’t help that around the end of Covid I went through a terrible break up and all my grad school friends finished their degrees and moved while I was still working on mine. It felt like I went to the bathroom at a party and came back to an empty room and I had to stay and clean up. I knew I’d be done in a year or two, so it felt weird to try and find a new social group when I was on short t…

I can relate to both comments. Covid really sapped the life out of me. Some relationships broke down during isolation, I lost friends, my fiancée left, I felt stuck in a job that I hated... The research into LLMs and diffusion models started to wake me up, but this superconductor research has, for some reason, really awoken something in me. I feel excited about the future– my future! – for the first time in a while.…

You need to continue down this path and find something meaningful to you that you had a hand in making directly, not merely by association. It is related to the power process described in paragraphs 33-37 on https://www.washingtonpost.com/wp-srv/national/longterm/unab...

Re: Electronic Structure of LK-99

#327

Post by orangepurple »

hcks wrote: post #247
appplication wrote: post #20

This ongoing research saga pretty much the most excited I’ve been about anything since before Covid. It feels like the science equivalent of watching your favorite sports team on an epic rise towards winning a world championship. Even if this turns out to flop, I hope history remembers the original authors favorably. They really did find something that by all accounts could plausibly be a room temp superconductor. An…

This is sad man. You’re getting excited at manufactured hype on twitter

Most people are powerless to do anything so they associate themselves with movements to feel as if they are part of something meaningful

Re: Electronic Structure of LK-99

#328

Post by yreg »

lucideer wrote: post #288

For anyone interested in this topic, there's a thread on Twitter that's been garnering some attention: https://nitter.net/Errorreporrt/status/1685835688216821760

Could we please stop giving attention to the obnoxious anonymous Russian troll who's only proof is a photo of a spec of dust in a syringe, who says she 'didnt follow the paper beause she immediately invented a better way to make a room temp superconductor', who says she 'doesnt care about superconductors' and keeps tweeting USSR propaganda?

I really don't get how she keeps getting recommended in these hacker news threads as an interesting source.

Re: Electronic Structure of LK-99

#329

Post by golol »

yreg wrote: post #268
golol wrote: post #211

Earlier quoted context omitted.

100% chance the guy is just lieing for attention or because he is delusional. He said that UFOs could be coming from extra dimensions. He might as well say that the UFOs are coming from atlantis or the second circle of hell. It's just horseshit, plain as.

> UFOs could be coming from extra dimensions I somehow find this perhaps more believable than the alternatives of (1) civs out there having FTL and not colonizing the Galaxy to the degree that we would detect it or (2) them coming here at sublight speeds to do the described UFO things.

I think the sad reality is that indeed (1) and (2) are extremely unlikely and that doesn't mean that extra dimensions is more likely. Extra dimensions is just even less likely.

Re: Electronic Structure of LK-99

#330

Post by norturnn »

bluecoconut wrote: post #12

I got my PhD studying band structure of high-tc superconductors (experimentalist, ARPES). These Cu d-d interactions right at the fermi energy give me huge hope. Feels very familiar to other superconductors (re: all the cuprates). (Note: I specifically worked in a lab that was measuring a lot of the d-wave character / gap-energies of various superconductors) All in all, I'm now much more bullish on LK-99 being real su…

Another ARPES person! Totally agree with you, not only the density of states but the flatness of the d band at the Fermi level is extremely encouraging. The simulated results look good enough that even if they had come out first I think that they still would have prompted someone to synthesize this.
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