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Supercomputing Science

A New Family of High-Temperature Superconductors 113

sciencehabit writes to let us know that physicists are hailing the discovery of a new type of superconductor as a "major advance." The new materials could solve the biggest mystery in condensed matter physics — i.e., how and why cuprate superconductors work — as well as paving the way for practical magnetic levitation and lossless transmission of energy. "God only knows where it will go," says one Nobel Laureate. After the discovery of superconductivity in an iron-and-arsenic compound at 26 kelvin, several Chinese research groups quickly found related materials that are superconducting up to 55K. (Cuprates go as high as 138K; liquid nitrogen boils at 77K.)
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A New Family of High-Temperature Superconductors

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  • Higgs? (Score:1, Offtopic)

    by sm62704 ( 957197 )
    "God only knows where it will go," says one Nobel Laureate.

    They found the Higgs boson? []
    • It's a misquote BTW, taking the whole thing out of context. The full quote is:

      "If it's really a new mechanism, God knows where it will go," he says.

      One must at the very least indicate that it is a partial quote, like so:

      "...God knows where it will go."

      The "..." indicates that the first part has been cut off.
      • Actually, it's not required to be considered a proper quote. Yeah, it can be abused to take things out of context, but RTFA.
      • by sm62704 ( 957197 )
        It was a joke, and it must really have sucked because nobody seemed to have gotten it. Higgs="god particle"

        Tough room
    • by sm62704 ( 957197 )
      To the mods "WOOSH!

      To quote Foghorn Leghorn, "It's a joke, son. Don't ya get it?"

      How can you not get that simple joke and call yourselves nerds? Jesus, folks, itt isn't rocket science. It isn't even subatomic particle physics!

      The Higgs bosun is called "the god particle". I even linked the fucking Wikipedia article in case there were morons with mod points.
  • by gmuslera ( 3436 )
    "High-Temperature Superconductors", the article say somewhere that "ignited a firestorm of research", and all of that because the temp at which are superconductors is 55 not celcius, not farenheit, but kelvin.

    I know that from very few over 0k to 55k there is a big difference, not sure how high they can reach, but still, looks a bit too low for "practical" implementation yet.
    • Re:Hot! (Score:5, Interesting)

      by Ctrl-Z ( 28806 ) <tim.timcoleman@com> on Friday April 18, 2008 @12:08PM (#23118644) Homepage Journal

      The "firestorm" was ignited by the discovery of cuprate semiconductors, which "have critical temperatures in excess of 90 kelvin"[1], which is above the temperature of liquid nitrogen.

      [1] []

      • Re:Hot! (Score:4, Interesting)

        by explosivejared ( 1186049 ) <hagan,jared&gmail,com> on Friday April 18, 2008 @12:20PM (#23118802)
        The article specifically mentions 138 kelvins as the highest temperature where cuprates still hold on to superconductivity. That's roughly -115 degrees celsius. This greatly increases the viability of the material by greatly reducing the energy required to hold it at a critical temperature. Think about the wide extent to which liquid nitrogen is used.

        Currently we are in the stage of trying to understand just what exactly is going on at the particle level. Once we move past this research stage (disclaimer: it's been going on for twenty years), the possibilities these materials provide are pretty much endless.
        • Re:Hot! (Score:5, Funny)

          by DieByWire ( 744043 ) on Friday April 18, 2008 @02:34PM (#23120812)

          The article specifically mentions 138 kelvins as the highest temperature where cuprates still hold on to superconductivity. That's roughly -115 degrees celsius.

          I believe you mean -135 degrees celsius.

          That last twenty degrees is what keeps Minnesota from superconducting in winter.

        • Re: (Score:3, Insightful)

          by Rei ( 128717 )
          The big deal with this discovery isn't that the possibilities the new materials they've found are endless. They actually underperform what we already have. It's that we don't understand how what we have (cuprate superconductors) works, but if we did, we could potentially find much higher-temperature superconductors. This gives us a key to help understand high temperature superconductivity. And the possibilities of high-temperature superconductors would be endless (assuming they could be made affordably).
      • Re: (Score:1, Offtopic)

        by Joe Snipe ( 224958 )
        For a less technical view of how cool this is:
    • Re:Hot! (Score:5, Informative)

      by jellomizer ( 103300 ) on Friday April 18, 2008 @12:14PM (#23118724)
      Well there is a huge difference in the price for using Liquid Nitrogin vs. Liquid Helium. Right now for superconductors used in MRI's they use Liquid Helium at 4k. And they use Liquid Nitrogin as an insolator to protect caseing from cracking. At roughly $1000.00 per leter of Liquid He, Liquid Nitrogin is much cheaper. Anf if they can get to a point where you can maintain superconductivity at Dry Ice level it would cause far more advances in society.
      • Re:Hot! (Score:5, Informative)

        by evanbd ( 210358 ) on Friday April 18, 2008 @01:11PM (#23119576)

        Where do you get $1k/L? A quick google search turns up $3-5 per liter, which is about what I recalled. LN2, of course, is much cheaper -- $0.25 in small quantities, $0.05 per liter or less in very large quantities.

        Dry ice is more expensive than LN2, because you have to pay for the CO2, rather than just liquefying air. But if you don't actually need dry ice, then dry ice temps are certainly cheaper to reach than LN2 temps.

      • Re:Hot! (Score:5, Informative)

        by krlynch ( 158571 ) on Friday April 18, 2008 @01:25PM (#23119828) Homepage

        At roughly $1000.00 per leter of Liquid He, Liquid Nitrogin is much cheaper.

        You've got the right idea, but your numbers are a bit out of whack ... LN2 is about $0.10/L in large quantity, while LHe is about $3-20/L, with large variation in price around the world (due to constrained supply and large transportation and energy costs). US He is relatively cheap, as we have a few of the small number of high quality sources. In Europe, He is very much more expensive, as they don't have any local, high quality sources. A recent compilation of costs is available here: []

        Helium is so expensive, because it is very entery intensive to liquify, and it isn't commercially extracted from the atmosphere like nitrogen ... there just isn't enough of it to be commercially viable. Instead, it is generally found in pockets underground and "mined". The helium originates as alpha particles in the decay of radioisotopes (mostly Uranium and Thorium), and permeates through the crust. It gets trapped in high pressure gas pockets by impermeable rocks, in the same types of geology that trap natural gas, and is extracted for commercial scale from those pockets. There are only a few global sources where the concentrations of helium are high enough to extract economically.
      • Most gasses have boiling points higher than nitrogen's, but there's at least one option between cheap liquid nitrogen and expensive liquid helium, which is liquid Neon [], which boils at 24.5 kelvin. The Wikipedia article says it's not cheap, but not as expensive as liquid helium, has better refrigeration properties, and is extracted from air rather than rare sources that risk exhaustion.
    • A big goal is to get superconductors to work at 77K, because then they can be cooled by cheap liquid nitrogen. Lower than that, you have to use liquid helium(I think) which is quite expensive.
      • by Ken_g6 ( 775014 )
        Technically, a superconductor that works at over 20.28 K can be cooled by liquid hydrogen.

        One problem, of course, is that liquid hydrogen is rocket fuel!
    • Re:Hot! (Score:5, Informative)

      by ThreeGigs ( 239452 ) on Friday April 18, 2008 @12:17PM (#23118770)
      The excitement isn't about superconductivity at 55K by itself. It's got everyone excited because, *finally*, there's something besides cuprates that superconducts above about 33K (which defines high temperature in the superconductor world).

      Now, instead of having just one 'family' of HTSC materials to base hypotheses and theories upon, scientists now have TWO. Now they can compare similarities and differences between those two families. This gives them a HUGE boost towards figuring out the exact mechanism involved, plus potential leads on new materials that exhibit similar atomic structure which could also superconduct.
    • Very Hot! (Score:4, Insightful)

      by l2718 ( 514756 ) on Friday April 18, 2008 @12:18PM (#23118792)

      1. "High T_c" is a technical term. Indeed, 55 kelvin is "high" (though not as high as the record for cuprates). You have to compare it with the typical T_c for metals (a few kelvin). The difference is between liquid helium temperatures and liquid nitrogen temperatures (which cuprates have reached already and perhaps the new compounds also will).

      2. More improtantly, this will ignite a "firestorm of research". You see, we don't have a good model of high T_c superconductivity (unlike the BCS [] model for metals). Having several different superconducting systems will help theorists isolate the significant features of the system from the less significant ones.

      3. Seeing superconductivity in a totally new material is exciting. This is interesting basic research even if today we dont' have a practical application. If we don't do the research we'll never get to the practical stage.

      • Very informative and coherent post. I am personally in the middle of the "firestorm of research" myself. I am a graduate student and have personally made a 52K superconductor. My professor has the entire group (about 10 people) working on this and I am about to post a preprint article on the data taken so far. This is a very exciting time to be a graduate student. It has been 12-14 hour days for me and a few others for the past few weeks. Not since the discovery of MgB2 in early 2001 has the field bee
    • I know of at least 5 superconductor power lines installed in the USA.

      The important point was getting over 77k, where the relatively cheap liquid nitrogen can be used instead of other things like liquid helium.
      • Re: (Score:1, Funny)

        by Anonymous Coward
        Of course, at 77k, you could run the lines through Soviet Russia... in the summertime! aaa ha ha ha. /isr temperature jokes
    • by bperkins ( 12056 )
      looks a bit too low for "practical" implementation yet.

      At this point people are more interested in the physics rather than the practical applications.

      This discovery is pretty important, because as TFA says, the exact mechanism that allows high temperature superconductivity to occur isn't widely agreed upon. Another system to study makes it much more likely that theorists will agree on exactly how this works.

  • by explosivejared ( 1186049 ) <hagan,jared&gmail,com> on Friday April 18, 2008 @12:04PM (#23118582)
    Here (PDF warning) [] is an in depth look at high temperature superconductors, especially the cuprate families, for those not well versed in the subject.
  • by 4D6963 ( 933028 ) on Friday April 18, 2008 @12:16PM (#23118760)

    as well as paving the way for practical magnetic levitation

    Awesome! Can't wait for my superconductor magnetic levitation bed!

  • Didn't we just see a far warmer superconductor just a little while ago? []

    Not to mention this one [] operating at 200 kelvin.

    I feel kind of bad for these guys doing their research and coming in 150 kelvin behind everyone else.
    • by Andy Dodd ( 701 ) <atd7.cornell@edu> on Friday April 18, 2008 @12:30PM (#23118980) Homepage
      It is news not because of any new temperature records, but because of the fact that these are the first superconductors outside of the cuprate family to exhibit high critical temperatures.

      This is an entirely new family from the cuprates. The cuprates started much lower too. Also, even if this family never compares to the cuprates in performance, the behavior of this new family could shed light on the (relatively unknown) mechanisms of cuprate superconductivity, allowing for that family to be developed further.
    • Did you even bother to even read the summary? The discovery isn't because they are surpassing some sort of high temperature for superconductors. It's because they've discovered NEW compounds that can be used as superconductors which can help scientists in improving the theoretical models behind how superconducting works.
      • I read the summary and TFA, and still wasn't impressed. Sure, the new iron/arsenic compounds are somewhat interesting, and maybe in the future holds some kind of potential. It just seems a little underwhelming, since other research is producing compunds that seem more promising.
  • Levitation (Score:4, Funny)

    by HTH NE1 ( 675604 ) on Friday April 18, 2008 @12:23PM (#23118860)

    as well as paving the way for practical magnetic levitation
    Just let me know when I don't need to have my feet frozen to my hoverboard to make it work.
  • And we all know that communists never lie.
  • Damn girl, you look hot enough to transmit energy in a lossless....hey, where are you going?
  • Are these "not so low" temperature superconductors usable to make semiconductors for computers? Can such a superconducting computer be run at extremely high clock rates, or just extremely low circuit latency, to make really fast computers not limited by the heat inefficiencies of today's regular computer chemistry?

    If so, how about building these computers buried in Antarctic ice? Winter air temperature drops to -80C; deep in the ice it's probably even lower. 138K is -211C. So the energy required to cool the
    • I am waiting with interest for an informed response to your question. But my guess is that a superconductor is only half of a supersemiconductor, which is the name I just made up for something that's instantly switchable from 0 to infinite resistance. And since infinite resistance is impossible, I would guess there will still be some current leaking through any real semiconductor, and thus waste heat. Besides the direct loss of this heat, it would make it harder to keep the superconducting parts cold en
      • While we both wait for someone informed to explain how we can or cannot currently fashion superconducting materials into transistors, we can speculated from an informed theoretical perspective :).

        The answer to the problem you pose (other than how the device's physical chemistry actually makes a supersemiconductor) is just to cool the part that much lower than its superconducting point. The energy is still lost to the extra heat from imperfect resistance, and multiplied by the energy consumed in recooling th
    • Re: (Score:3, Insightful)

      by Jerf ( 17166 )

      The problem is what to do with the heat pumped out, which could damage the arctic nearby, maybe even melt the foundation. But if the total mass cooled is small (like a few dozen microchips), that byproduct heat could be used to keep some human operators alive.

      Scale, scale, scale, scale, scale. Don't let environmentalist mottos fool you; humans aren't actually "heating" the planet. By pumping large amounts of a greenhouse gas into the atmosphere, we are causing the planet to retain more heat. (This isn't new

      • Re: (Score:3, Informative)

        The poster was talking about local heating effects, not global, and while you're right that a few computers won't create a heat island and change the local ecology, there is one sort of local effect that is quite real and well-known all across the Arctic. Any warm structure will heat the ground it is built on slightly, and in the high Arctic where permafrost [] exists, anything you build (including all buildings and pipelines) has to take this into account or the permafrost melts and the structure sinks. The
      • As the other reply to your message [] said, I'm not talking about upsetting the ecosystem in the arctic. I'm talking about melting the ice supporting the delicate machinery.

        FWIW, the "environmentalist mottoes" are just fine. We are heating the planet, by stopping its natural cooling radiation with our thickened Greenhouse atmosphere. The same way I "warm up" by putting on a coat, even if the coat isn't that warm to start with. In fact we can directly heat the planet, and of course we do, though the effects of
    • I don't really have a lot to say, but you made one error. Zero degrees C is 273K, so 138K is actually -135 degrees C, not -211.


      • You're right, 138K == -135C [], thanks.

        Which means that the ice, even if it's only -80C, is only 55C hotter than the -135C superconducting point. Unlike the usual labs, which at about 24C (I doublechecked [] ;) are 159C hotter. An even better case for arctic super(conducting computers).
  • > physicists are hailing the discovery of a new
    > type of superconductor...
    > as well as paving the way for practical magnetic
    > levitation and lossless transmission of energy.

    Lossless transmission = 0 entropy

    0 entropy (Isolated system? Transmission line, check. Not in equilibrium? Voltage gradient, check) = violation of the second law of thermodynamics: "The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium."

    When others mak
    • by nmos ( 25822 )
      In fairness most proposals for perpetual motion machines (actually all that I've seen) actually claim decreasing entropy, not just zero change. IANAP but I do wonder if superconductivity will turn out not to be completely lossless but just very very nearly lossless. Of course, in practice we're not talking about closed systems anyway.
    • Are you sure there is a voltage gradient across a superconducting transmission line?
    • If you have a transmission line, you have an input and an output, and so you do not have an isolated system. There is not a voltage gradient within a superconducting transmission line (simplistically, V = IR = 0, since R=0), even if you have one at terminals on either end. In fact, measure the voltage at points on a copper wire in a circuit, and you can see that the voltage gradient within the wire is (practically) zero. You can have an apparent violation of entropy pretty easily, if you define your "isol
  • Has anyone noticed the disconnect between this topic (superconducting) and the icon (supercomputing) Slashdot is using to summarize this topic? I know they both have the word "super"... and a "c". But the similarities end there.

    Supercomputing is all about massively parallel computation, not just computers... nor chips. This article is about condensed matter physics and (who knows?) a possible replacement for the semiconductor.

    Got a semiconductor icon, perhaps?
  • Your idea of what constitutes "high temperature" and my idea of what constitutes "high temperature" are radically different. Until it runs in my house wiring it really isn't going to impact me any time soon.

    Interesting term "firestorm" to describe the interest in this discovery. One is left thinking that the intense firestorm has resulted in pushing temperatures so high that all the superconducting stopped right there.

  • It is a shame that more theoretical progress hasn't been made on high Tc superconductors. This would be a project ripe for distributed computing.

  • "Several Chinese research groups quickly found related materials...."

    Were those Chinese researh groups at US univeristies or actually in China?

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