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

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.)

17 of 126 comments (clear)

  1. 100 percent efficiency? by Anonymous Coward · · Score: 4, Insightful

    Seems unlikely. Something about complimentary midday meals...

    1. Re:100 percent efficiency? by Anonymous Coward · · Score: 5, Informative

      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.

    2. Re:100 percent efficiency? by bunratty · · Score: 4, Funny

      Check your calculator. According to mine, 1 000 000 / 999 900 = 1.000 100 010 001

      --
      What a fool believes, he sees, no wise man has the power to reason away.
    3. Re:100 percent efficiency? by ArcadeMan · · Score: 5, Funny

      Still using that old Pentium, eh?

  2. Re:really? by Stolpskott · · Score: 5, Insightful

    It is right and proper to have doubts about new announcements like this. That is the basis of science - the idea of "replicate, then trust, but verify" at the core of scientific approaches. If this turns out to be either an error, a late April-fools joke, a scam, a one-off result that cannot be replicated, or a valid result within a small range of constraints, then it will be labelled as such.
    However, if subsequent independent experiments show a robust and consistent process that can be replicated easily, then I for one will welcome our new (1 atom-thick) tinfoil hat-wearing overlords...

  3. Re:I call bull by Anonymous Coward · · Score: 4, Informative

    There is no such thing as conducting electricity at 100 percent efficiency. Think about it... it implies perpetual machines, and I believe there's some evidence against the possibility of such a thing :D

    You are wrong.
    The evidence against perpetual machines are only for machines with a higher than 100 percent efficiency, not machines that approaches 100 percent efficiency. You can have a wheel in space that spins perpetually, you cannot extract energy from it without slowing it down.
    Also, as far as I know the 'proof' is based on a statistical observation of how energy works with a macroscopic number of particles.
    While it is highly unlikely that anyone can build an energy creator by working on a subatomic level I don't think that there is any hard evidence that proves this impossible. To get that proof one would probably have to explain why matter and energy exists at all and why it can't happen again.

  4. It's all simulations! by queazocotal · · Score: 5, Insightful

    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.

    1. Re:It's all simulations! by StripedCow · · Score: 5, Interesting

      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?

      --
      If Pandora's box is destined to be opened, *I* want to be the one to open it.
    2. Re:It's all simulations! by overshoot · · Score: 5, Informative

      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.

      --
      Lacking <sarcasm> tags, /. substitutes moderation as "Troll."
  5. Re:I call bull by Anonymous Coward · · Score: 4, Funny

    AC, Superconductor. Superconductor, this is AC.

  6. Link to non-paywalled version of paper by lars_stefan_axelsson · · Score: 5, Informative

    Arxiv to the rescue: http://arxiv.org/abs/1306.3008 (This may lack editorial changes etc. made by the journal, but should be factually complete.)

    --
    Stefan Axelsson
  7. Great... by Cryacin · · Score: 4, Funny

    NOW they tell me my tinfoil hat in fact amplifies my brainwaves to be read. THANKS A LOT LONE GUNMEN!

    --
    Science advances one funeral at a time- Max Planck
  8. Single layer by overshoot · · Score: 5, Informative

    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.

    --
    Lacking <sarcasm> tags, /. substitutes moderation as "Troll."
  9. A link to the Arxiv version of the paper by Glubbdrubb · · Score: 4, Informative
  10. Re:really? by Kickasso · · Score: 5, Insightful

    Bzzzt! wrong. If I trust you, I will verify your work. If I don't trust you, I won't even bother to look at it.

    Trust is about honesty, not about infallibility.

  11. Re:really? by K.+S.+Kyosuke · · Score: 5, Informative

    the losses are capacitive, you can reduce the losses by making smaller transistors but you really cant affect it by material selection

    Yeah, the reason why material selection doesn't matter in capacitors is precisely why many of them are being manufactured using the fairly rare element named tantalum. It's just for the fun of it. ;-) Perhaps you're right about the interconnect material selection but there's a lot of material selection going on in modern ICs beyond that.

    --
    Ezekiel 23:20
  12. not a superconductor, a topological insulator by Goldsmith · · Score: 5, Informative

    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.