The place that uses the same sort of techniques as research physicists is the microchip industry. They can get away with it because they need extreme purity and make something that is, pound for pound, extremely valuable. If superconductors have to be made like that, they're going to be very expensive, used in niche applications but not bringing the power to your house.
The solution to mass production is to find a way to make it with vapor deposition. The comparison to solar cells is probably the best one here. Also because of the role of government subsidies in pushing process up the learning curve.
I recently read an article about molybdenum disulfide which in particular profiled Jie Shan and Kin Fai Mak who do research on the material at Cornell. It included, almost as asides, a bunch of tasks that needed to be accomplished even before the material made it out of the study phase (where it still is). Things like:
Wang’s group, for one, fell back on graphene after finding that they couldn’t easily attach metal electrodes to moly disulfide. “That has been the stumbling block for our group for quite a few years,” he said. “Even now we are not very good at making contact.”
But when Hone’s group placed moly disulfide on an insulator, the properties of the stack showed lackluster gains compared to what they had seen in graphene. Eventually they realized that they hadn’t checked the quality of the TMD crystals. When they had some colleagues stick their moly disulfide under a microscope capable of resolving individual atoms, they were stunned. Some atoms sat in the wrong place, while others had gone missing entirely. As many as 1 in 100 lattice sites had some problem, impeding the lattice’s ability to direct electrons.
I point to this one as being directly germane to the LK99 case, where the method of manufacturing the material was so simple that I read early predictions that there would be a flood of failed replications due to how much variation the methods allowed for and how even amateurs could attempt it. It may still be the case that confirmation is blocked on a consistent procedure for making the stuff.
They also spent years figuring out how to lift and stack the microscopic flakes, which measure just tenths of millionths of a meter across. With this ability, plus Hone’s crystals and improved electrical contacts, everything came together in 2018.
This looks like a problem that could be tackled right now for LK99 and the proposed similar materials.
One of the first steps would be figure out the theory of how it works, and based on it, synthesize ambient SC materials that are easy to produce repeatably and reliably and are easy to work with. The next steps depend on the outcome of that undertaking.
Even if we know how a room temp superconductor works, that doesn't mean we can predict new materials with arbitrary combinations of properties. We more or less understand how iron-based high temperature superconductors work, but that hasn't led to a spate of designer unconventional superconductors. Prediction is just hard. People will certainly make educated guesses about how to turn any new superconductor into a "family" of superconductors related by small changes, but that's very phenomenological.
Well, yes, we do understand the low-temp superconductors and its limitations. We do not really understand High-Tc superconductors, and it seems to impair the search for better versions. It's quite possible that if LK-99 turns out to be more than a false positive, its workings might still remain an open problem for a long time. Or maybe, as you suggest, we figure out how it works, but still will not be able to use it to guide the design of something significantly more convenient. So, yeah, it is possible that the search for more convenient versions will be left to material scientists rather than physicists proper. Still, it seems like there is a lot of improvement needed before we can produce these potential ambient superconductors in useful quantities and sizes.
Tabling the question of whether LK99 itself is a room temperature superconductor, I wonder about how we would commercialize it assuming it (or something similar) is, as rapidly as possible. I was reading Ben Reinhardt's Metalessons from the LK-99 Saga post, which raised the point that it normally takes a few decades for an invention to commercially mature. This is consistent with the perspective from Gordon's The Rise and Fall of American Growth (summary), and Smil's Creating the Twentieth Century.
First, I would like the benefits of widespread superconduction sooner than 20 years. Second, given the US/EU's moderate-to-severe distaste for capital-intensive work these paste couple of decades, I think there's a too-high-for-sanity risk that the historical picture is optimistic and we might in fact go slower or fail to exploit the discovery at all.
So then, what should we do? I think we should be able to generate a plausible roadmap of all the tasks that need to be accomplished for widespread commercialization, and then it would be nice if we could sort of speed-run founding the businesses required to push it that far. I am looking for answers that cover the kinds of tasks that need to be done, businesses that will need to be created, etc. Another good kind of answer would be comparison cases: should we look at the road to commercialization for transistors? Fiber-optic cable? Copper cable? Et cetera.