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Single-Atom Layer of Tin May Be a New Wonder Conductor 126

Posted by timothy
from the but-does-it-have-heart? dept.
At Kurzweil AI, an article proclaims that the next wonder material for computer chips may be an unexpectedly common one: "Move over, graphene. 'Stanene' — a single layer of tin atoms — could be the world’s first material to conduct electricity with 100 percent efficiency at the temperatures that computer chips operate, according to a team of theoretical physicists led by researchers from the U.S. Department of Energy’s (DOE) SLAC National Accelerator Laboratory and Stanford University." (Original paper is available here, but paywalled.)
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Single-Atom Layer of Tin May Be a New Wonder Conductor

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  • by Anonymous Coward on Monday November 25, 2013 @07:36AM (#45513243)

    Seems unlikely. Something about complimentary midday meals...

    • by Anonymous Coward on Monday November 25, 2013 @07:49AM (#45513285)

      Well if we are talking about power transmissions then superconductors are 100% efficient. Nil resistive losses. You still have capacitive and inductive losses you cant get rid of when dealing with AC or DC ramp up, ramp down. You also have external costs like keeping the superconductor cooled, but that is system efficiency, not semiconductor efficiency, that is cooling cost is not dependent on power transmitted. So if you are looking at time invariant current and exclude cooling costs then superconductors are 100% efficient in current transmission.

      • by Anonymous Coward
        Cooling this will be virtually free. Water at any significant elevation above sea-level will boil before 100c.
      • If you don't have resistance, any capacitive or inductive effects will be 100% efficient, no?. The whole problem with induction and capacitance in transmission lines is it increases the overall power loss due to unused current flowing through resistive lines. Superconductivity eliminates that source of loss.

        • by Agripa (139780)

          If you don't have resistance, any capacitive or inductive effects will be 100% efficient, no?

          No. Dielectric polarization losses in capacitors and hysteresis and eddy current losses in inductors will still exist when superconductors are used. In high voltage high voltage power transmission lines, corona discharge losses will still exist.

    • by oobayly (1056050) on Monday November 25, 2013 @07:50AM (#45513291)

      It's not a problem, in the small print they've defined % as 999900 ppm

    • Trust nothing. This is just a secret government ploy to lower the supplies for mind control protective headgear.

    • by Hobadee (787558)

      if($string = "100 percent efficiency"){
          printf("Bullshit!");
      }

  • by queazocotal (915608) on Monday November 25, 2013 @08:14AM (#45513365)

    At least as far as I can tell without access to the paywalled concept.
    Important questions would be:

    What is the maximum current that can be transported through strips of various widths?
    How sensitive to defects is the process?

    Tin is going to be a major problem for much semiconductor processing - as it means you basically now can't solder the chip, or do any even 'low' temperature processing after it's deposited - it has to be the last layer.

    • by StripedCow (776465) on Monday November 25, 2013 @08:52AM (#45513503)

      What is the maximum current that can be transported through strips of various widths?

      Other questions:

      1. If a sheet of 1 atom thickness can transport x A/m at no loss, (ampere per meter of sheet), then how close can you stack these sheets together before x becomes significantly less?

      2. If there is a (mutual) magnetic interference between two layers that destroys the superconducting effect, then will the superconductor actually work when immersed in an external magnetic field?

      • by overshoot (39700)

        Other questions:

        1. If a sheet of 1 atom thickness can transport x A/m at no loss, (ampere per meter of sheet), then how close can you stack these sheets together before x becomes significantly less?

        And the related question of whether the change is dramatic enough that it can be used for active devices. Hmmmm ...

        Note that this is much less of an issue for power distribution on-chip because stacking layers can dramatically reduce field strength by coupling currents in opposite directions (and incidentally create bypass capacitance, of which there is never enough.)

        2. If there is a (mutual) magnetic interference between two layers that destroys the superconducting effect, then will the superconductor actually work when immersed in an external magnetic field?

        Unless the critical field is really low, which seems unlikely at room temperature, this isn't going to be a problem for anyone not building

      • by Zmobie (2478450)

        I'm no materials engineer/scientist, but I would think some of this could be overcome simply by width and orientation of the tin strips. Considering that TFA stated that this is only conducting on the edges of the "stanene" you could probably somewhat pyramid the tin layers with some type of insulator between them and the resulting magnetic field size could be accounted for at each layer such that they don't interfere with each other. Also by just making sure major strips were run perpendicular to each ot

    • by overshoot (39700) on Monday November 25, 2013 @09:02AM (#45513541)

      What is the maximum current that can be transported through strips of various widths?

      Mostly moot. The really nasty consequence of conductive losses in semiconductors is that it degrades signals traveling across the chip. We insert buffers along the route to restore signal amplitude and reduce delays (those RC delays are ugly). This would zero the resistance and reduce the capacitance, which is a big deal. Also, for reliability reasons, we'd probably build laminates with multiple layers separated by dielectrics.

      How sensitive to defects is the process?

      Depends on the width of the path. The usual solution is to add redundancy, multiple single-atom layers separated by dielectric. Vertical space on chips is relatively cheap, as long as you don't need to use extra mask layers or move the material from one process stage to another.

      Tin is going to be a major problem for much semiconductor processing - as it means you basically now can't solder the chip, or do any even 'low' temperature processing after it's deposited - it has to be the last layer.

      We don't solder the devices directly anyway -- the organic dielectrics used in advanced processes like the old metal-melting temperatures even less than tin does.

    • It's all simulations!

      Little early to be getting metaphysical.

    • by Anonymous Coward

      ....Tin is going to be a major problem for much semiconductor processing - as it means you basically now can't solder the chip, or do any even 'low' temperature processing after it's deposited - it has to be the last layer.

      From the article:

      "...adding fluorine atoms to the tin would extend its operating range to at least 100 degrees Celsius (212 degrees Fahrenheit)."

    • by tlhIngan (30335)

      Tin is going to be a major problem for much semiconductor processing - as it means you basically now can't solder the chip, or do any even 'low' temperature processing after it's deposited - it has to be the last layer.

      It's even worse than that. Tin whiskers - it's a characteristic of the metal. No one knows why, the only suspicion we have is Tin does it to relieve stress in the crystal.

      And it appears atoms are willing to migrate from all throughout the bulk to whiskers - if you look at whiskers under a mic

      • It's even worse than that. Tin whiskers - it's a characteristic of the metal. No one knows why, the only suspicion we have is Tin does it to relieve stress in the crystal.

        Fullerenes aren't crystals, though. For the same reason that graphene and nanotubes don't have carbon wandering around all over the place, neither is tin likely to. In fact, given the higher mass of a tin atom compared to carbon, it could be a whole lot harder to get one to leave its place in the array.

  • by lars_stefan_axelsson (236283) on Monday November 25, 2013 @08:21AM (#45513387) Homepage
    Arxiv to the rescue: http://arxiv.org/abs/1306.3008 [arxiv.org] (This may lack editorial changes etc. made by the journal, but should be factually complete.)
  • Single layer (Score:5, Informative)

    by overshoot (39700) on Monday November 25, 2013 @08:53AM (#45513507)

    For those of you not in the semiconductor business, the fact that these conductive strips is pretty important too. Most of the capacitance (that has to be charged and discharged whenever a node switches, causing losses in the transistors driving the node) is sidewall capacitance: capacitance between adjacent lines on the same level. Single-layer conductors won't completely do away with lateral capacitance (fringing, for instance) and the vertical capacitance will still be there -- but there's going to be a big reduction in power if they can get this to work. My guess is that by the time it reaches production it won't exactly be one layer, either -- it'll be a laminate with multiple redundant layers.

    Always assuming the predictions play out.

  • So it can conduct small current with little or no resistance
    and its not scaalable
    good for chips, but you're not going to be transporting gigwatts or power from the wind farms to the cities with no losses, or improving the efficiency of your electric car.

    • by Anonymous Coward

      OK, so you have found two applications where it isn't usable.

      In computers it is on the other hand very usable. Take a look at an i7-920 [intel.com]
      With a core voltage at ~1V and a TDP of 130W you have about 130A circling around there in total.
      Even with a relatively small resistivity of 5mohm/cm you have a lot of losses in the conductive paths in the chip at currents like that.
      It is not an insignificant improvement in battery life on laptops and phones and the reduction in cooling in desktops and server racks isn't some

  • For someone who is not an expert in the field, what is the efficiency of the conductor? It seems to refer to the fact that no charge is lost (dissipated) between the ends of the conductor, but it's not clear.

    I assume since no one used the word "superconductor" that it has a finite resistance; does anyone know what the resistance is? (would large bundles of these conductors be useful for energy transport?)

  • Right, the usual fundme bullshit wrapped as article. Come back when you have something beyond speculation.
    • Come back when you have something beyond speculation.

      Well done on completely failing to understand what research is.

    • by jo_ham (604554)

      How else, pray tell, are in silica calculations going to be described any other way?

      It's a little more than "speculation", but I figure your armchair science degree probably didn't prepare you for that.

  • by Goldsmith (561202) on Monday November 25, 2013 @10:55AM (#45514441)

    These guys are talking about a 2D topological insulator. This is the current hot area of research in condensed matter physics, and is absolutely not a superconductor.

    A topological insulator is best described as an insulator, which for very particular types of conduction (direction, location and energy limited) acts like a very good metal. It's really interesting, and scientists are trying to show it will have practical use, and these materials might end up in a computer chip in a few years, but...

    There is a big difference between a lab effect and the real world. Carbon nanotubes have most of the same "non scattering" effects you'd hope to find in a topological insulator. Yet, in most actual devices, they do not conduct in bulk the way theory would suggest. For nanoscale systems (these are nanoscale systems) the environment around the material is nearly as important as the material itself, and scattering from the environment (oxides, metals, air) drastically reduces the performance of the material. There are ways around that, but the additional costs and engineering difficulty are generally enough to prevent any practical commercialization.

  • by Anonymous Coward

    Here's a pdf of the full article:

    http://www.scribd.com/doc/186970759/Xu-Y-Binghai-Y-Hai-Hun-Z-Jing-W-Gang-X-Peizhe-T-Wenhui-D-Shou-Cheng-Z-2013-Large-Gap-Quantum-Spin-Hall-Insulators-in-Tin-Fi?secret_password=1s8nqw1pazkc9kw6m3i7

  • Really, that's what we had to drag our butts through interstellar space for? Unobtanium is just tin?
  • For those interested in a more in-depth treatment... http://arxiv.org/pdf/1306.3008.pdf [arxiv.org]

  • but scientists are now hard at work to develop larger tin atoms.

All this wheeling and dealing around, why, it isn't for money, it's for fun. Money's just the way we keep score. -- Henry Tyroon

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