Superconductivity record sparks wave of follow-up physics

http://www.nature.com/news/superconductivity-record-sparks-wave-of-follow-up-physics-1.18191

by jgamman • 11 years ago

93 44 11 years ago

nature.com

mcphage• 11 years ago

At 203K... and 1.5 million atmospheres of pressure.

x3n0ph3n3• 11 years ago

Wow, that should not be understated!

jgamman• 11 years ago

but still... 203K!? i remember the 90s when the last round of leap frogging superconductor materials were being developed - every conference even vaguely related to solid state chem/physics seemed to set a new record. And H2S? it's hardly an exotic material. maybe it's just the (near dead) chemist in me geeking out ;-)

cbd1984• 11 years ago

the (near dead) chemist

Work around enough H2S and it will take you the rest of the way.

My point is, it has enough problems with flagrant toxicity that containment of non-trivial amounts of it will be either massively expensive, totally inadequate (especially in the event of an earthquake, fire, fire caused by earthquake...), or both.

venomsnake• 11 years ago

That is not that high ... after all we need a pipe only couple of microns thick.

baq• 11 years ago

that's not exactly true, when you feed a superconductor too much current, it breaks down, and it can take more if it's "fatter".

dantiberian• 11 years ago

This would certainly give new meaning to the phrase "Letting out the magic smoke".

https://en.wikipedia.org/wiki/Magic_smoke

hwstar• 11 years ago

You may be killed. H2S is very toxic.

mikeash• 11 years ago

I doubt the toxicity would do you much harm. There should be no risk of taking the gas into your lungs, as after the release of 150 gigapascals of pressure, you'll probably be nowhere near them.

nickhalfasleep• 11 years ago

I wonder if any of the Gas Giants in system reach this at any depth of their atmosphere? Jupiter and Saturn look too hot. But Uranus or Neptune?

chris_va• 11 years ago

If I'm reading this right, it gets up to ~600K by the time it hits the right pressure for Neptune.

http://www.aanda.org/articles/aa/full/2005/03/aa1695/aa1695....

idlewords3• 11 years ago

H2S fun facts! It's more lethal than hydrogen cyanide, and despite its powerful stench at low concentrations (detectable by humans at half a part per billion), it becomes odorless (by paralyzing your sense of smell) right around when you need to start getting worried.

"A diagnostic clue of extreme poisoning by H2S is the discolouration of copper coins in the pockets of the victim"

beloch2• 11 years ago

Safety procedure when working around sour gas wells (natural gas with H2S) is that, if you see somebody drop in front of you, you do not touch him, approach him, or anything else. You just get the hell outta there. If he's been dropped by H2S, trying to move him is just going to cause you to go down too. Besides being bloody lethal, H2S is notorious for being corrosive. H2S forms metal sulfides with any exposed metal it can access, and the hydrogen byproduct often diffuses through the metal and forms expanding holidays in positions of stress, potentially to the point that the metal will crack.

I've worked around high power free-space infrared lasers where a single stray reflection could instantly blind you permanently (and you can't see infrared light scattering off of stuff like you can with visible lasers). I'd rather spend years working with those than spend one afternoon in a lab with a sample of H2S at 140 GPa. I don't care if it's inside a diamond anvil cell inside a cryostat. High pressure H2S has got to be a freakin' nightmare to work with. I'm sure H2S has lots of funky properties nobody knows about because practically nobody wants to work with the stuff. Kudos to the PI who convinced a bunch of grad student peons to put their lives on the line... I suppose.

ars• 11 years ago

in a lab with a sample of H2S at 140 GPa. High pressure H2S has got to be a freakin' nightmare to work with.

They probably have absolutely tiny quantities of the stuff under pressure. Not enough to hurt anyone even if it escaped.

Turing_Machine2• 11 years ago

"it becomes odorless (by paralyzing your sense of smell) right around when you need to start getting worried"

I don't know if this is still the case in this litigation-happy age (probably not), but when I was in high school it was a common beginner's chem class experiment to make small quantities of H2S.

My physics teacher once commented that he hated it when they did that, because he'd smell it for a while, then not smell it any more -- leaving him to wonder whether it'd just gone away, or whether people were going to start keeling over.

sleeping_pills• 11 years ago

Ah the good old days of worry free high school chemistry/physics classes. My chem teacher poured out a pint of mercury and allowed us to push our fingers into it to feel how different it was from liquids like water. Good times.

mkoryak• 11 years ago

Is bringing a substance to 1.5 million atm cheaper than cooling it to under -70C ?

All the articles I read on the topic seem to imply that higher temperatures are much more important than a bit of super high pressure, but can someone explain why?

danarlow2• 11 years ago

The big application for superconductors is wire, and it's much harder to compress a wire to a million atm than it is to cool it to -70 C. However, this result is important (if independently replicated) because it demonstrates that the established theory of low temperature superconductivity [1] has predictive power all the way up to these high temperatures and likely to room temperature, providing new motivation for theoretical chemists to dream up new materials that the theory predicts would superconduct under more accessible conditions. Practical room temperature superconductors would, in my opinion, change the world as much as the development of semiconductors.

[1] a modified version of BCS Theory https://en.wikipedia.org/wiki/BCS_theory

Turing_Machine2• 11 years ago

"Practical room temperature superconductors would, in my opinion, change the world as much as the development of semiconductors"

It would be huge, definitely. Even the most obvious application (reducing electric power transmission losses) would be worth billions. According to the Googles, ~4000 TWh generated annually, 6% transmission losses, $.09/kWh gives about $22 billion in annual savings in the United States alone (if I didn't mess up the arithmetic).

xt00• 11 years ago

The reason why this is so important is that simpler molecules are much easier to simulate and work with from the theoretical side to create a bulletproof model of how the high temperature superconductors work. All of the cooper pairs and all that stuff took years and years to figure out because the molecule was something like yttrium barium copper oxide.. which is complicated as all hell to figure out what the electrons are doing inside of it while in a crystalline form.. H2S is basically like "sulfur plus some protons" is so much more simple to simulate with something like molecular dynamics methods to figure out what is going on with it. What the researchers probably are hoping to come out of this is a recipe for superconductivity based upon a crystalline form of some material that can be made in a low-cost fashion that superconducts at high temp..

jkn• 11 years ago

Maintaining a low temperature requires continuous work as you can't stop heat transfer completely. This consumes energy and requires some machinery to produce or deliver the coolant.

Establishing and maintaining a high pressure on the other hand is a one time effort, for example screwing back the front of a ballpoint pen puts the spring inside under permanent pressure, and even gases can be contained at high pressure with no significant loss.

eghad• 11 years ago

If anyone is wondering how we're capable of testing these under 150 GPa, read up on Diamond Anvil Cells (they're palm-sized): https://str.llnl.gov/str/pdfs/03_96.2.pdf https://en.wikipedia.org/wiki/Diamond_anvil_cell

analognoise• 11 years ago

Thanks, my Google-fu was weak and kept getting me pages on unit conversion. :)

steve19• 11 years ago

Is room temperature super conductivity theoretically possible?

idlewords3• 11 years ago

Depends on how many sweaters you have.

delecti• 11 years ago

Well I'm not aware of any commonly accepted current theories of super conductivity that say a room temperature one is necessarily impossible, so I suppose implicitly yes.

thangalin• 11 years ago

http://www.nature.com/nature/journal/v516/n7529/full/nature1...

acjohnson55• 11 years ago

It was right under our noses, all along!

tlb• 11 years ago

I don't have a good mental model of solids at very high pressures. Temperature is a measure of kinetic energy, but because the atoms are squeezed closer together the stiffness of the lattice is higher, therefore the displacement due thermal vibrations at a given temperature is less.

I wonder if the displacement at 203K and 1.5M atm is similar to the displacement at which conventional BCS superconductors operate.

dunkelheit2• 11 years ago

Actually in thermodynamic terms temperature is a measure of how entropy (disorder) increases when you increase internal energy. Not the most intuitive definition (you can't just go and buy entropyometer for example ;)) but it works even when quantum effects kick in. And for ideal gas this measure happens to be proportional to the kinetic energy of the particles.

jessriedel• 11 years ago

This is a really interesting framing. If it's the correct way to think about things, it would really put a damper on the importance of warm-temperatures/extreme-pressure superconductors.

dunkelheit2• 11 years ago

other hydrogen compounds may be good candidates for high-temperature superconductivity too

If this is true there will be a mini gold rush in this space in the next couple of years. Maybe the record will not stand for very long.

eddyb• 11 years ago

Every time I see news of sub-zero superconductivity I get reminded that this site exists http://superconductors.org/ and there's no debunking or confirming of anything on it.

You'd think that all these years, someone with the right equipment would at least have the least bit of curiosity and try out one of those crystal configurations.

If it doesn't work, make it public, maybe repeat the negative findings a few times and nobody would have to wonder "but what if?".

If it does work, well, the rest of the thread explains what would happen to technology in that case.

One odd theory I've come across is that he may be intentionally avoiding publicity just enough so that he can get patents filed for everything before any of this stuff starts being used in production.

While that's too much conspiracy for me, it's either that or "nobody knows (or cares) whether he's a charlatan or not" and it keeps bugging me until I forget about it.

Superconductivity record sparks wave of follow-up physics

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