Superconductivity without cooling? | Hacker News Reader

Superconductivity without cooling?

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191 pointsNoelkd19 comments

The actual publication, http://www.nature.com/nature/journal/v516/n7529/full/nature1..., is not quite so bold as to say they've demonstrated room temperature superconductivity, rather:

"Among these, the enhancement in the dx2-y2 character of the in-plane electronic structure is likely to favour superconductivity."

They cite two of their past publications, "Optically enhanced coherent transport in YBa2Cu3O6.5 by ultrafast redistribution of interlayer coupling," and "Optically induced coherent transport far above Tc in underdoped YBCuO." If they had actually unequivocally shown pulsed YBCO to be superconducting at room temperature the title would be more like, "ROOM TEMPERATURE SUPERCONDUCTIVITY YES!!!!!"

The real demonstration of superconductivity is measuring a Meissner effect (exclusion of magnetic field) in the material (https://en.wikipedia.org/wiki/Meissner_effect). I haven't read the articles in detail, but it sounds to me like they have seen some properties that are similar to those found in the superconducting state, but they have not measured a definitive signature of superconductivity.

Was going to say something similar. But even though the results are not room temperature superconductors, it does have some tantalizing hints of ways that we might get there.

This is a great example of scientific reporting: it deals with the findings of the research itself rather than some "human" narrative, and it names and cites the actual materials and publications involved while using common language where possible.

Also, a very cool finding. Interesting that only a few picometers of atomic shift yields superconductivity at room temperature.

It might not sound like a lot but you need to put it in the scale of the atoms. That is about a 1% change in atomic spacing, which means a 1% strain applied to the sample, which is pretty big (think about how much weight you'd need to hang off of a steel bar to get it to stretch by 1%).

Pressure and strain are known to have large effects on superconductivity. In fact the highest known Tc of any material is HgBCuO under externally applied pressure (http://en.wikipedia.org/wiki/High-temperature_superconductiv...).

Room temperature superconductivity (0 Celsius) = perpetual motion machine to me. They are both stored in the same region of my brain. This would CHANGE EVERYTHING

Finding a room temperature superconductor "would have enormous technological importance and, for example, help to solve the world’s energy problems, provide for faster computers, allow for novel memory-storage devices, and enable ultra-sensitive sensors, among many other possibilities." from http://researcher.watson.ibm.com/researcher/view_group.php?i...

why is it any more or less a perpetual motion machine than a low temperature superconductor?

before you suggest that it's because there's energy input to draw off the heat consider that if you took a low-t superconductor to pluto, it would still superconduct.

From the electron's perspective, all superconductors are sort of perpetual motion machines. A perpetual motion machine is basically just any lossless kinetic system, so if you count electron flow in a loop of superconductor as a kinetic system, then it qualifies.

edit - These folk sell a 2MJ one - http://www.bruker-est.com/bas_special_applications.html

That kind of storage without the cooling requirements would be pretty useful...

From the article, superconductivity is already possible at "higher" temperatures (-200 Celsius). Why would 0 Celsius specifically make it "perpetual motion machine" like to you (in the sense of breaking some fundamental physical law)? If I recall correctly, 0 Celsius is not a very significant number apart for being the freezing point of water.

STP[1] is 0 °C, 100 kPa. It's room temperature for science.

Edit: The significance of this is that superconductors that operate at room temperature did not exist. If they come into existence, and mature, you can expect to see the development of technology which appears to be powered by magic.

[1] https://en.wikipedia.org/wiki/Standard_conditions_for_temper...

I understand that the practical implications of room temperature superconductivity would be huge.

I simply found the "= perpetual motion machine" part strange given that such machines are known to be impossible while >0K superconductivity is known to be possible (and if superconductivity is impossible past a given temperature, it would be a surprising coincidence if that temperature happened to be 273.15K). Now that I read the comment again, the original commenter probably didn't mean it literally.

Well it is literally perpetual motion.

And yes as far as exact temperature it's about qualitative differences, not quantitative ones.

The first revolutionary hurdle is making it work on a desktop with a simple fridge-style cooling mechanism.

The second hurdle is making it work around 40-50C, then your phone and almost everything can take advantage of it.

> perpetual motion machine to me

Yeah, but it's a perpetual motion machine in the same sense that everything is; all particles evolve in time, i.e. the values of all six quantum fields change ceaselessly. The controversial (imaginary) perpetual motion machine is one that you can extract unlimited amounts of energy from.

Which is really funny to me, since energy is essentially defined as the constant that does not change in time (well, excluding general relativity).

Nuts, this fell off the front page before I could write this, so probably nobody will ever see it.

> The precise mechanism remained unclear, however – until the physicists were able to solve the mystery with an experiment at the LCLS in the US, the world’s most powerful X-ray laser.

Neither Stanford nor SLAC gets a mention here. I wonder if the article author deliberated over whether to include their names and then decided not to, or if it was just an oversight. Either option is not great for SLAC.

The national labs don't get nearly the love they ought to. One almost never hears about them unless it's Los Alamos or Livermore.

Maybe we'll have an MRI in every home someday.

Not today, and tomorrow isn't looking good either. But if i had to make a 100 year bet, i'd bet fmri's are the human computer interface of the future.

I don't think that's a good idea, because of the active RF transmissions and strong magnetic fields needed.

Passive measurements like MEG could work a lot better, though they have some problems with being sensitive to disturbances....

The future of the 1980s predicted it would be SQUIDs, as in Gibson's "Johnny Mnemonic". By comparison, fMRI, which looks at changes in blood flow, is slower than straight MRI with SQUID detectors.

If I had to make a 100 year bet on what would be the human computer interface of the future, after getting it contractually agreed that whoever is forcing me to place this bet is responsible for me surviving another 100 years, I would probably then bet on Tetris, just to annoy everyone.

That said, I don't think it will be fmri either. Personally, I'd be betting on something involving an implanted optical lace driving genetically modified cell sites, with possibly a shielded skull to actually block rf shenanigans, as a futuristic nod to all the tinfoil hat wearers.

I can't imagine the ultimate HMI being anything but synaptic, specifically a bio-engineered cell which has a human synapse on one end and an electromagnetic interface on the other.

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