Slashdot Mirror


Possible Room Temperature Superconductor Achieved

TechkNighT_1337 sends news that surfaced on the Next Big Future blog, concerning research out of the University of Bengal, in India. The report is of a possible superconducting effect at ambient room temperatures. Here is the paper on the ArXiv. (Note that this research has not been peer-reviewed or published yet.) "We report the observation of an exceptionally large room-temperature electrical conductivity in silver and aluminum layers deposited on a lead zirconate titanate (PZT) substrate. The surface resistance of the silver-coated samples also shows a sharp change near 313 K. The results are strongly suggestive of a superconductive interfacial layer, and have been interpreted in the framework of Bose-Einstein condensation of bipolarons as the suggested mechanism for high-temperature superconductivity in cuprates. ... The fact that the results described above have been obtained from very simply-fabricated systems, without the use of any sophisticated set-up and any special attention being given to crystal purity, atomic perfection, lattice matching, etc. suggests that the physical process is a universal one, involving only an interface between a metal and an insulator with a large low-frequency dielectric constant. We note in passing that PZT and the cuprates have similar (perovskite or perovskite-based) crystal structures. This resemblance may provide an added insight into the basic mechanism of high-temperature superconductivity."

47 of 264 comments (clear)

  1. Of course! by Anonymous Coward · · Score: 5, Funny

    After reading the summary, everything is plainly obvious...

    (walks away slowly before anyone can notice I didn't understand anything)

    1. Re:Of course! by thrawn_aj · · Score: 5, Informative

      *sigh* It's even worse than that. IAAP and I was very excited to see this ... at first. The article by the way is very well written (serious science - not a crank). The problem is that the data (figure 2 in the arxiv paper - everyone should check this out btw) on which the author hangs all his hopes is seriously noisy (compared to the size of the "kink" that he superposes on the graph). In other words, if you imagine erasing the drawn-in kink, such artifacts occur several places in the data and are generally not above the noise level.

      So, I would say that the conclusion is highly unwarranted given the state of the existing signal to noise. However, if the author truly feels there's something promising, he simply has to go about improving his signal. To be fair, the /. title is far more ambitious compared to the original article (indications of ...). He's merely putting this out in the wild to get feedback from other researchers in the field (which is solely what Arxiv is used for by serious researchers, not as a publication destination).

      As it stands, the "kink" seems to be nothing more than (one of several) noise bumps. I'll be keeping an eye on this guy of course. Maybe something might come out of this, who know?

    2. Re:Of course! by getuid() · · Score: 5, Insightful

      *sigh* It's even worse than that. IAAP and I was very excited to see this ... at first. The article by the way is very well written (serious science - not a crank). The problem is that the data (figure 2 in the arxiv paper - everyone should check this out btw) on which the author hangs all his hopes is seriously noisy (compared to the size of the "kink" that he superposes on the graph). In other words, if you imagine erasing the drawn-in kink, such artifacts occur several places in the data and are generally not above the noise level.

      Not necessarily. When analysing experimental data, keep in mind that it's not only the ~5 points of the kink that carry relevant information, it's *all* the points! Thus, the proper way to look at the graph would be to focus first the lower half (up to the kink), and then on the upper half, and see what's changed. If, for example, linear fits to the separate data regions give separate straight lines, this could mean that there is something in the data.

      That having been said: although IAAS (I am a scientist), I'm not a transport measurements guy and I'm not familiar with the state-of-the-art methods in this particular experimental technique... The guys improving their experimental technique would certainly not hurt at all, but for now, I'd leave it to the peer reviewers to estimate the relevance of *this* particular graph ;-)

    3. Re:Of course! by ctrl-alt-canc · · Score: 3, Interesting

      Totally agree. I too find that the measurements reported in the paper are quite suspicious. Furthermore I have noticed that there is no mention about the oscillator frequency used for collecting the data shown in figure 2, so it is difficult to judge how much significant is the "kink" upon which most of the paper claims are standing. It is also questionable the fact that he had to use a current excitation signal at 20 Hz in order to improve the measurement. PZT is a well-known piezoelectric material, so I wonder if his measurements were simply contaminated by noise induced by periodical mechanical vibrations: unfortunately in the paper there is no mention about the physical setup of his experiment (neither he reports how many PZT strips he tested...).

      By the way...IAAP, although not working on superconductors :-(

    4. Re:Of course! by RelativeKny · · Score: 5, Informative

      IAAP too, although in experimental LOW-Tc superconductivity. I agree, although with even more reservations. Not only is the data noisy, but the author claims, that microvolts is "extremely low voltage". This is absolutely rubbish from an experimentalist point of view. It has (obviously from the plots) not been filtered, and the authors claim of a "homebuilt amplifier built on an AD620" is not confidence inspiring. Although the AD620 is not horrible, noise-wise it is used at DC (20 Hz is close enough), which means that 1/f noise will kill his signal no matter what he does. This is especially silly considering, that nothing in the setup should require this low frequency sweeps. Hook up a lock-in amplifier and run ia at a few kHz at least to get decent noise characteristics. Also, all the experimental details of the setup are missing - this alone will get the paper rejected from any peer-reviewed journal. The author might be on to something interesting - superconductivity or not - but the experiment is done like a theorist would, not like an experimental physicist would. Back to the lab, and get some better results - I would love to see this with better measurements. PS: I'm not trying to re-ignite ye olde theorist vs. experimentalist battle, btw - I believe it is possible to be both. Just saying, that the author of this article is not. Seems he has a decent grasp of the theory though, hence my comment to theorists ;-)

    5. Re:Of course! by arachnoprobe · · Score: 5, Insightful

      I think he knows that his experimental data is crap. The note on the dirtiness of the procedures in the abstracts hints to the fact, that he put out one sample and accidentally found what could be something hyper-interesting. Out of fear of being out-published by someone else, he put out this paper, that - if this is an RT superconductor - he can (rightly) claim having discovered it (leading to wealth and nobel price). Now he can go back an do some proper experiments.

  2. Wait until it has been repeated. by BLToday · · Score: 5, Insightful

    until the experiment has been repeated by someone else, I'm not holding any hope.

    1. Re:Wait until it has been repeated. by djtachyon · · Score: 3, Funny

      Absolute Zero ;)

      --
      "What's the use of a good quotation if you can't change it?" - Doctor Who
    2. Re:Wait until it has been repeated. by Anonymous Coward · · Score: 4, Insightful

      until the experiment has been repeated by someone else, I'm not holding any hope.

      I tend to agree. This falls into the too good to be true category. Simple materials and a fairly straightforward relatively low tech process to make it reeks of cold fusion. Also showing signs of superconductivity has always been a vague statement and rather noncommittal. Saying that crystal purity didn't seem to be a factor also appears questionable since that would normally be critical to achieving superconductivity. It's a little like saying you just made a 100% efficient photovoltaic cell out of plain ole beach sand. Not real likely.

    3. Re:Wait until it has been repeated. by vbraga · · Score: 5, Funny

      Maybe we could just redefine what room temperature is!

      --
      English is not my first language. Corrections and suggestions are welcome.
    4. Re:Wait until it has been repeated. by thrawn_aj · · Score: 3, Funny

      FAPP (For all practical purpose)

      No offense, but I sincerely hope that acronym does not catch on =)

    5. Re:Wait until it has been repeated. by Surt · · Score: 3, Funny

      Too late. FAPP FAPP FAPP ... it's all over the internet FAPP FAPP FAPP.

      --
      "Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
  3. I had this sneaky suspicion... by Anonymous Coward · · Score: 4, Funny

    it was Bose-Einstein condensation of bipolarons that would allow for room tempurature super conduction.

  4. ...really? by linuxgeek64 · · Score: 5, Insightful

    Not peer-reviewed and not published = why the fuck is this on Slashdot?!

    1. Re:...really? by EmagGeek · · Score: 4, Funny

      Didn't you just answer your own question?

    2. Re:...really? by MobileTatsu-NJG · · Score: 4, Insightful

      Not peer-reviewed and not published = why the fuck is this on Slashdot?!

      Because ad revenue goes up while everybody discusses how it shouldn't be on Slashdot.

      --

      "I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)

    3. Re:...really? by nashv · · Score: 5, Insightful

      Because in physics, people have the good sense to let the larger community take a look before these bureaucratic procedures are finished. That is why ArXiv exists,and if Slashdot does its bit, why the hell not?

      --
      Entia non sunt multiplicanda praeter necessitatem.
  5. Room Temperature in UK, maybe not in India? by billstewart · · Score: 4, Funny

    313K is 40C. So this stuff ought to behave just fine in the UK, but only part of the year in India :-) Even in temperate climates, you'd have to be careful not to leave it out in the sun, so again it should be fine in the UK...

    --

    Bill Stewart
    New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
    1. Re:Room Temperature in UK, maybe not in India? by JamesP · · Score: 5, Funny

      Reminds me of that joke about scientists in Anchorage discovering a room-temperature superconductor :P

      --
      how long until /. fixes commenting on Chrome?
    2. Re:Room Temperature in UK, maybe not in India? by RsG · · Score: 4, Insightful

      This is why we prefer the term "high temperature superconductor" over "room temperature". Superconductivity at 313K, if even possible, is still a damn big deal.

      And for a lot of applications, anywhere near ambient temperature is good enough. If the cooling system needed is no more complex than a home AC unit, you've removed the primary drawback/limit on practical superconductors, namely the need for cyrogenic liquids.

      --
      Erotic is when you use a feather. Exotic is when you use the whole chicken.
  6. Cold Fusion by Fartypants · · Score: 5, Insightful

    This smells of Cold fusion. I was 12 when that scandal erupted and I'm *still* recovering from the disappointment that we hadn't just entered the age of flying cars. This time I think we're better off saving our excitement until the experiment has been repeated.

    1. Re:Cold Fusion by hAckz0r · · Score: 4, Interesting
      Yes, its best to be sceptical on this one. But I can assure you that Cold Fusion is real, but very hard to reproduce in the Lab and completely working by principals that nobody yet understands. I do work in a Physics Lab, and had the honour of sitting in on a lecture from a well renowned co-worker who explained what we do and do not know about it to date. Its real.

      The unfortunate reality is that *because of the scandal*, and under the current political fallout conditions, it is considered professional suicide to even get evolved with it. Any projects you are working on will immediately become unfunded, even those not directly related to Cold Fusion. The politics are a formidable problem with moving the technology forward, and that is not likely to change any time soon. Someday it will no longer be taboo to work on it, but for now don't hold your breath. Bad politics can kill almost any 'good thing' despite the clear benefits it might possess for the future. Right now the only way it will ever move forward is through private funding.

    2. Re:Cold Fusion by Idarubicin · · Score: 5, Funny
      Ah. Well-renowned scientific co-worker endorses cold fusion. Inside scoop from globally-acclaimed Slashdot science critic hAckzOr.

      "It's real", hAckzor concludes.

      Film at eleven. Take that, scientific establishment.

      --
      ~Idarubicin
    3. Re:Cold Fusion by Anonymous Coward · · Score: 5, Informative

      Cold Fusion has more than just political problems: it's a matter of energy scales. To overcome the Coulomb barrier between deuterium and tritium, after which the strong interaction takes over, requires an energy of about 4.5 x 10^7 Kelvin. This is the lowest energy fusion reaction. Now imagine how much energy you can get from the strongest chemical reaction. How about thermite: 2500 K, you're still off by four orders of magnitude. That's the main reason why physicists avoid Cold Fusion.

      The current superconductivity article is better, in that the underlying physics is at least plausible, but as a previous poster pointed out, the signal to noise ratio is low, even after smoothing has been applied. Also 4000 Angstroms of deposited Al seems to be somewhat on the thick side for the dielectric to have any effect. But it's certainly worth trying to reproduce the results. (IAAP specializing in superconductivity).

    4. Re:Cold Fusion by TheTurtlesMoves · · Score: 4, Insightful

      Cold fusion as reported is clearly not real. Either 2 things must be true. That the energy came from D+D->He3+p+T+n in which case the neutron radiation would have killed them both. Or that D+D->He4 +gamma , just about everything in the standard model is completely wrong, observed data from particle physics is wrong, observed data from nuclear testing is wrong, and they would both be dead from gamma radiation.

      They claimed that the power was 1 watt. A number so high that detecting the reaction is totally trivial.. for example if you are in the room for a few hours, you die without a decent piece of shielding.

      The current experiments show some interesting facts too. No one can get any decent signal above the noise, while home built fusors totally destroy cold fusion with easily detectable reaction rates (on the order of 10^6 reaction per second IIRC). Hell even diode tube neutron sources destroy them for reaction rate.

      --
      The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
  7. The catches by BlueParrot · · Score: 5, Informative

    There has been a number of fraud reports of high temperature superconductivity, and while there are some confirmed examples of superconductivity at very high temperatures ( like -70C ) they usually involve some microscopic crystal or other structure which is not very useful for most practical applications.

    In addition, that something super conducts does not imply it can handle a very large current at high temperatures. The current creates a magnetic field, and superconductors can only work when the magnetic field is less than some fixed value that depends on the material. If I'm not mistaken this value is at its highest when the temperature is very low, and thus it's quite plausible you could get a room temperature superconductor which can't carry any significant current unless cooled to more traditional temperatures.

    1. Re:The catches by Mad+Bad+Rabbit · · Score: 3, Informative

      Even if it had a low critical current, the alleged room-temperature superconductor would be useful for SQUIDs and Josephson junctions.

      --
      >;k
    2. Re:The catches by bertok · · Score: 5, Interesting

      Yes, but the small crystals are usually a side-effect of the technique used to find novel superconducting compounds. What some groups do is create polycrystalline lumps where each crystal has a slightly different formula. Then they test resistivity with changing temperature across the whole lot. If just one crystal superconducts, there will be a 'kink' in the graph. This is like a simple brute-force method for testing many samples in parallel, but doesn't necessarily provide a formula that an be produced in bulk.

      It's like a mathematical proof that states that something "must exist" without providing an actual value.

      Also, superconductors are inherently useful irrespective of the current carrying capacity. For example, Josephson Junctions and RSFQ digital electronics are both very useful and require very low power.

      Even a "thin-film" superconductor like the one described in the article would be very useful, as that can be practical for integrated circuitry, even if it's not possible to make a flexible wire out of it.

  8. Re:Someone didn't get the memo by Man+On+Pink+Corner · · Score: 4, Insightful

    If it superconducts at room temperature, trust me, nobody's going to give a crap what it's made from.

  9. Re:This will later be known as... by ductonius · · Score: 4, Informative

    No he didn't.

  10. Balogna by Maury+Markowitz · · Score: 3, Interesting

    > The surface resistance of the silver-coated samples also shows a sharp change near 313 K.

    Pure copper does the exact same thing.

    I call bogus.

    Maury

  11. Reminds me of Futurama... by Anonymous Coward · · Score: 3, Funny

    Yes, I see. Something involving that many big words could easily destabilize time itself!

  12. Re:Someone didn't get the memo by Eudial · · Score: 3, Insightful

    Well, silver isn't -that- expensive. Especially when we're just speaking of a layer of the stuff.

    --
    GAAH! MY PRINTER IS ON FIRE!!! PUT IT OUT! PUT IT OUT!
  13. The Other Important Question by BlackGriffen · · Score: 3, Informative

    How much current can it carry? Superconductors tend to lose superconductivity in the presence of a large magnetic field, limiting the amount of current they can carry. I don't know if the high Tc superconductors are more susceptible than the regular ones, but it's something to keep in mind.

    If they can take a really high magnetic field then that would be really cool for projects like the LHC. A large part of what makes that project dangerous, difficult, and expensive is the large number of He cooled superconducting magnets it needs. The danger comes in when you get a cosmic ray or something that increases the temperature of the magnet so that even a small part loses its superconductivity. When that happens, the non-superconducting part rapidly starts heating up the rest of the magnet in a process called "quenching." The results of a quench can be quite catastrophic.

    1. Re:The Other Important Question by Ungrounded+Lightning · · Score: 4, Interesting

      Superconductors tend to lose superconductivity in the presence of a large magnetic field, limiting the amount of current they can carry.

      Type I yes. Type II no.

      The latter makes current whirlpools that pinch the magnetic field into little quantized columns, which arrange themselves in a hexagonal grid. Superconduction quits in the narrow column where the mag field penetrates, but continues just fine in the rest of the material, dodging around the columns. The field must be very strong to make a lattice of mag field penetrations so dense that they merge and all superconduction crosswise to the mag field quits.

      Not that it matters:

      Superconductors are useful for a LOT of stuff besides carrying power around. Being able to make thin-film superconductor elements with a critical temperature, not just of an air conditioned room, but of a human body with a moderately high fever, would be very useful. (You could keep it cool enough to keep working, even inside a piece of hot equipment on a hot day, with a Peltier junction cooler. No problem.)

      --
      Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
  14. Re:Someone didn't get the memo by thestudio_bob · · Score: 5, Funny

    ...not something made of silver.

    Well, apparently you don't have to deal with electricity stealing Werewolves. I for one, am glad someone is finally addressing this problem.

    --
    The real Sig captains the Northwestern. This one captains /.
  15. Meissner effect? by AJWM · · Score: 4, Interesting

    Magnetic levitation photos or it didn't happen.

    --
    -- Alastair
    1. Re:Meissner effect? by GNUALMAFUERTE · · Score: 4, Funny

      Fucking room temperature superconductors, how do they work?

      --
      WTF am I doing replying to an AC at 5 A.M on a Friday night?
  16. Superconductivity Breakthrough! by Adrian+Lopez · · Score: 3, Insightful

    The report is of a possible superconducting effect at ambient room temperatures.

    Amazing! Simply ama...

    Here is the paper on the ArXiv.

    ... Oh.

    --
    "In prison you just have to shut your eyes and take it. Here you have to shut your eyes and give it."
    1. Re:Superconductivity Breakthrough! by TheTurtlesMoves · · Score: 4, Insightful

      Guess where all (well most) serious physics publications start?

      Peer review is not as magical as you think it is.

      And as someone who peer reviews... why do i waste my time reading these papers that are only on ArXiv?

      --
      The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
  17. Re:Two weeks old, no citations or trackbacks by deglr6328 · · Score: 3, Interesting

    Lisi's E8 paper has been cited like 17 times. I'd say that's pretty good and hardly constitutes "no scientists commenting on it in 3 years". It's usually a good bet, but overhyped media publicity doesn't ALWAYS automatically mean someone's work is shit. Lisi's theory makes concrete falsifiable predictions for new particles that will either be confirmed or ruled out using the LHC's dataset.

    --
    - "Hear that?! The percolations are imminent! Cease your ingress!"
  18. Re:This will later be known as... by epine · · Score: 5, Insightful

    The word (and concept) of "unobtainium" goes back to the 50s at least, actually.

    If the term "unobtainium" wasn't invented by the early heyday of jet fighter engineering (circa the Korean war), I'll eat my carbon-graphite bike frame.

    My understanding is that superconductors have current limits independent of resistive effects (possibly due to magnetic field intensity). How much material you need depends on those exact limits. Even silver could be cheap as dirt if the current density is high enough.

    The other thing I've heard is that superconductors are generally discovered by observing related effects, not by measuring conductivity itself.

    There also seems to be many people here who have never heard of the black swan effect. You can't prove a black swan doesn't exist by observing a sequence of white swans. There's always a first time. This also applies to the possibility that something important is someday discovered or first published independent of peer review.

    That said, there's no point in wearing out your salivary glands unnecessarily, although I've heard it's a common ailment to overdose on visual innuendo of the possibility of doing something you're not actually doing (with dim prospects).

    For me qualified engineering porn is when the material is officially characterized in important criteria such as current density limits.

    I feel the same way about quantum computing. Still haven't seen a formula which describes the ultimate constraint (or cost) on how many qubits can be stacked together (usually the universe puts limits on salivary endeavours). It would be kind of weird if qubits prove to be as stackable as frictionless pulleys.

  19. Extraordinary claims require evidence. by dr.+loser · · Score: 5, Informative

    I'm a condensed matter physicist. This claim is weak beyond belief, and it pains me to no end to see it get picked up by slashdot and other sites (nextbigfuture.com). To demonstrate superconductivity, you need to show (a) zero resistance over some range of current; (b) the Meissner effect (expulsion of magnetic flux, seen via magnetometry); (c) a characteristic feature of a phase transition in the heat capacity. This paper shows exactly none of these things. The noise level in the resistance measurements is so poor, you could not tell the difference between zero and 0.01 Ohms (which would be totally believable considering there is already a metal film in the system). This paper in its present form is not fit for publication. Seriously, you don't have to be an expert at this stuff to see that this is weak - just look at the noise level in the current-voltage curves and use some common sense!

  20. The Bipolorons!!! by RevWaldo · · Score: 4, Funny

    Three of Earth's most chemically imbalanced heros!

    It's The Manic Maurauder! (POW!)
    The Hyperthymic Huntress! (ZAP!)
    And The Depressed Defender! (Mwah-mwahhh!)

    Using their insanity in a never-ending battle against crime and the forces of evil!

    They're off their meds and on the case! It's The Bipolorons!!

    .

  21. Re: move along now by thrawn_aj · · Score: 4, Interesting

    Nothing you said is relevant except for the actual paper, which is well written (and doesn't read like a crank - he appears to be fully cognizant of the current state of the field). I've posted (elsewhere on this page) exactly why this conclusion is unlikely (based on a critique of the actual arxiv paper). Further, the author does not claim what the summary here states (another reason to RTFA) - he merely states that it may be an indication of superconductivity in the context of a specific model that was published a while ago (in a mainstream journal). You might want to take a minute to look into it before showing your ignorance with such ludicrous rants.

  22. Re: move along now by NeutronCowboy · · Score: 3, Insightful

    Riddle me this: if "considering the source" is the only valid criterion on which a person's authority on a subject rests, then how the hell does said person achieve enough authority to ever pass the "consider the source" test?

    Considering the source is a shortcut for where to look for interesting papers. It does not, however, have anything to do with the validity of the data itself.

    Is it an extraordinary claim? Sure is. Is it valid to wait for someone with some authority to make similar claims before judging that paper? Sure is. Is it possible to dismiss the claims immediately? Complete,utter, bullshit. Your entire argument rests on semantic and personal judgments. There is not a single iota of science in your post. It beats the hell out of me how you got modded up.

    --
    Those who can, do. Those who can't, sue.
  23. Re:Two weeks old, no citations or trackbacks by deglr6328 · · Score: 4, Insightful

    Yeah, I guess that's why he just co-authored "Unification of gravity, gauge fields, and Higgs bosons" with Perimeter Institute physicist Lee Smolin then, huh.....'cause he's just such a joke.

    --
    - "Hear that?! The percolations are imminent! Cease your ingress!"