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Origin of correlated isolated flat bands in LK99

arxiv.org

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Re: Origin of correlated isolated flat bands in LK99

#61

Post by floxy »

jakeinspace wrote: post #40
losteric wrote: post #26

Earlier quoted context omitted.

Posting for Cunningham's law :) * Green energy suddenly becomes way more viable. Megaprojects in the most efficient sites can send energy long-distance and store it with effectively no loss, somewhat mitigating regional variations (especially if we have a high-trust world order where a united global grid is viable). (I read LK99 might have some limitations carrying lots of current but presumably other approaches woul…

Sorry, but how does one create a transistor from a superconductor? Maybe I’m missing something here.

Most superconducting logic families aren't using transistors at all. They use Josephson junctions, which are just two pieces of superconductor separated by a non-supercondutor. RSFQ (Rapid Single Flux Quantum) uses millivolt-high picosecond-long pulses to represent logic 1 and their absence as logic zero, instead of using voltage level as in CMOS.

https://ieeexplore.ieee.org/document/783712 (770 GHz toggle flip-flop in 1999)

https://www.physics.sunysb.edu/Physics/RSFQ/Projects/WhatIs/...

Re: Origin of correlated isolated flat bands in LK99

#62

Post by KRAKRISMOTT »

ivalm wrote: post #43
bibabaloo wrote: post #30

Earlier quoted context omitted.

If this could be simulated, can you help me understand why we couldn't have used simulation to find promising SC materials to investigate further earlier? Are there just too many permutations to investigate? It seems to my own naive self that if LK99 is the real deal, we mostly just got lucky finding it.

You have to put in the structure and then it's expensive to do the calculation. The space of possible structures is extremely large. If you have candidates then you can run through them, but you can't just random search through trillions of trillions of candidates.

What are all the material science ML companies doing? This would be a perfect technology demo if they can find the target

Re: Origin of correlated isolated flat bands in LK99

#63

Post by SamPatt »

drones wrote: post #9

Even if LK99 isn't the real deal, god has it been an exciting 2 weeks. Though I know absolutely nothing about material science, I have enjoyed the sheer enthusiasm and optimism the scientific community has shown. I feel like I'm part of something unique and special, something which could have only been achieved by the medium of accessible mass communication. The excitement here is palpable. I feel fortunate to be par…

I sometimes wonder what it would have been like to witness the emergence of fundamental new technologies, like electricity or radio.

Then I remember I'm further along the tech tree than they were, and what a gift that is. It's very exciting to watch it update in real time.

Now I'm envious of future generations (I think humanity has a bright future despite the current gloom groupthink).

Re: Origin of correlated isolated flat bands in LK99

#64

Post by dcow »

notfish wrote: post #46
dcow wrote: post #41

Earlier quoted context omitted.

I'm just saying that it's not really LK-99, then. It's something else that needs to be specified more precisely.

Defining LK-99 as “the thing you get from following the steps in this paper” and not “the allegedly superconducting material these guys have a sample of” is silly.

Why? I've always understood it to be the thing the paper describes.

Re: Origin of correlated isolated flat bands in LK99

#65

Post by ruined »

dtx1 wrote: post #60
ruined wrote: post #54

Earlier quoted context omitted.

musicians often use them to generate distortion, which is purely an electrical phenomenon. germanium components tend to filter high frequencies and don't clip as sharply as silicon, generating tonal effects that can't really be replicated. but mostly, a lot of early guitar pedals used germanium components, and so they are associated with prestigious historic guitar players. here's a video demonstration. silicon first…

> generating tonal effects that can't really be replicated. Seems my headphones can replicate it judging from hearing the audio. Am I missing something?

you're listening to a recording. a musician wants to make sound

Re: Origin of correlated isolated flat bands in LK99

#66

Post by lucubratory »

jacquesm wrote: post #50
dcow wrote: post #41

Earlier quoted context omitted.

I'm just saying that it's not really LK-99, then. It's something else that needs to be specified more precisely.

I'm not following you. The compound is specified, the process is what is poorly specified and the researchers more or less admit that they do not exactly know what the right method is. This makes it a lot harder to replicate and may well cause a lot of attempts to misfire before someone finds something that works or we give up on the search. What TFA here suggests is that there are some potential complications in man…

Pons and Fleischmann, not Jan Hendrik Schön?

Re: Origin of correlated isolated flat bands in LK99

#67

Post by wahnfrieden »

dtx1 wrote: post #60
ruined wrote: post #54

Earlier quoted context omitted.

musicians often use them to generate distortion, which is purely an electrical phenomenon. germanium components tend to filter high frequencies and don't clip as sharply as silicon, generating tonal effects that can't really be replicated. but mostly, a lot of early guitar pedals used germanium components, and so they are associated with prestigious historic guitar players. here's a video demonstration. silicon first…

> generating tonal effects that can't really be replicated. Seems my headphones can replicate it judging from hearing the audio. Am I missing something?

Synthesis not sample

Re: Origin of correlated isolated flat bands in LK99

#68

Post by montecarl »

seewhydee wrote: post #20

Don't get too excited --- theorists have predicted nine of the last five physics breakthroughs (pace Paul Samuelson).

Theory confirming experiment is quite different from theory predicting new physics. I think the best use of these types of ab initio DFT calculations is to interpret experimental results. Back in grad school, my theoretical chemistry group regularly was able to help clear up confusing experimental findings with these exact type of calculations (in fact using the same program as used in this paper, VASP).

Re: Origin of correlated isolated flat bands in LK99

#69

Post by bigmattystyles »

justrealist wrote: post #15

I really hope this unlocks a class of superconductors and isn't a bizarre oneoff compound, because the EPA of 2023 is not going to let us wire the country with thousands of miles of lead-based ceramic wire.

Isn’t lead ok as long as it’s not airborne/ ingested?

Re: Origin of correlated isolated flat bands in LK99

#70

Post by jacquesm »

KRAKRISMOTT wrote: post #62
ivalm wrote: post #43

Earlier quoted context omitted.

You have to put in the structure and then it's expensive to do the calculation. The space of possible structures is extremely large. If you have candidates then you can run through them, but you can't just random search through trillions of trillions of candidates.

What are all the material science ML companies doing? This would be a perfect technology demo if they can find the target

https://www.mpg.de/20096180/artificial-intelligence-in-mater...

They are doing this sort of thing (that's more of a research institute). The problem is that you are not looking for the compound but for the exact way to manufacture it assuming that the original sample really is superconducting.

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