So theorically they agree with LK-99 reaching superconductivity?
It's a process. Scientists will try to replicate and try to simulate and try to reason theoretically. They are bound to make mistakes but all of this can be critiqued and iterated on.
Again, there's no problem unless you need immediate confirmation or you think chasing this idea is a waste of time.
Enjoy the ride :)
The simulation paper folks are talking about used what appeared to be an existing DFT simulation package. Now, DFT is an approximate theory used to render computation tractable, but to my understanding it is a popular and mature method. I was actually kind of impressed that they were able to reproduce results from the LK paper in simulation so quickly. While it’s possible the speed led to a bug or error in the analysis, simulations often don’t just magically work and can take a decent amount of parameter tuning — especially if the system being simulated has something tricky or exotic going on. The fact that they were able to get what appears to be an accurate simulation working quickly that also justifies the low yield rates has made me more cautiously optimistic than anything
From my understanding (I am not a superconductor person, but in an adjacent field), having flat bands at the Fermi level is not that rare. Such features appear in other materials that are evidently not superconductors, room temperature or otherwise. So the conclusions are more along the lines of "maybe it wouldn't be totally crazy", rather than "omg, we predict this material has astounding properties".
Sounds like it, if prepared right it could be a super conductor and would NOT be a diamagnet that would display the properties we saw in those videos.
Even in robotics (my area), if you are watching a video of a robot doing something cool, there’s often a bunch of times they ran the same demo and it didn’t work for some (often largely irrelevant to the main idea) reason. I also remember, in an undergrad analog circuits class, we had to build an amplifier on a breadboard with certain performance specs (e.g., a fairly high cut off frequency, etc.). This ended up being fairly difficult due to the tolerances in the components to which we had access and breadboard parasitics. I recall getting a non-trivial performance boost by swapping out a dozen 2n2222’s until we found “a good one.” The gray beard professor laughed and said that’s an expected part of our practical education.
There is also Lawrence Livermore National Lab, which is nearby, but in Livermore. They do classified research in addition to non-classified. I suppose it's one of the two places they simulate nuclear weapons... errr, run large scale multi-physics combustion codes for stockpile stewardship.
Back in the '90s my friend (jokingly) lamented that they wouldn't let him try to play Everquest on their computer.
> Abstract: A recent report of room temperature superconductivity at ambient pressure in Cu-substituted apatite (`LK99') has invigorated interest in the understanding of what materials and mechanisms can allow for high-temperature superconductivity. Here I perform density functional theory calculations on Cu-substituted lead phosphate apatite, identifying correlated isolated flat bands at the Fermi level, a common signature of high transition temperatures in already established families of superconductors. I elucidate the origins of these isolated bands as arising from a structural distortion induced by the Cu ions and a chiral charge density wave from the Pb lone pairs. These results suggest that a minimal two-band model can encompass much of the low-energy physics in this system. Finally, I discuss the implications of my results on possible superconductivity in Cu-doped apatite
(put another way: it's post-hoc)
(I say this as somebody with a decade+ of experience running large ensembles of classical MD simulations, but not so much experience with inorganic DFT)
Turn the material science problem around: instead of looking for a substance that has a specific property, look at many substances until small amounts of any interesting property (young's modulus, etc) show up. By looking for "anything interesting" you are more likely to find something of interesting (ideally, several somethings). And then you also know a starting place to begin optimiziation.
(I'm not saying these things out of ignorance; this technique has worked well for me at times when I had exceptionally large amounts of CPU available to me, and it's also worked well in the drug industry, which has similar problems to material science.)
Also, at the end of the day, DFT is still an imperfect approximate model. Relative trends are generally more reliable than exact correspondence with experiment, and it can have system-specific systematic errors that are hard to account for in a high throughput setting
Edit: Also look at how long these (short pre-print) DFT articles are. These aren't simple calculations to interpret.
Real models for superconductivity take a lot of work to create, it's not something people do for an unverified material, and it's not something you get out of DFT. That paper's agreement is more on the lines of "yeah, all superconductors are grey, and this thing is grey, it can be."
But then, they talked about diamagnetism (graphite-like one, I imagine). Honestly, I have no idea how one could disprove (graphite-like) diamagnetism with that simulation, but disproving it is really good news.