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Technology Hardware Science

A Plasmonic Revolution for Computer Chips? 188

Roland Piquepaille writes "Today, we're using basically two ways to move data in our computers: transistors carry small amounts of data and are extremely small, while fiber optic cables can carry huge amounts of data, but are much bigger in size. Now, imagine a single technology combining the advantages of photonics and electronics. This Stanford University report says a new technology can do it: plasmonics. (For more about plasmons, read this Wikipedia article.) Theoretically, it is possible to design plasmonic components with the same materials used today by chipmakers, but with frequencies 100,000 times greater than the ones of current microprocessors. There is still a challenge to solve before getting plasmonic chips. Today, plasmons can only travel a few millimeters before dying, while today's chips are typically about a centimeter across. Read this overview for more details and references about plasmonics, and to discover why it's one possible future for chips' circuitry."
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A Plasmonic Revolution for Computer Chips?

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  • Alright (Score:5, Interesting)

    by OverlordQ ( 264228 ) on Monday April 04, 2005 @06:01PM (#12138371) Journal
    Lets keep it simple, put all of the Roland Piquepaille [thedarkcitadel.com] conspiracy posts here. :)

    Editors: GIVE HIM HIS OWN DAMN SECTION SO CAN HIDE HIS POSTS
    • Re:Alright (Score:1, Offtopic)

      by Doc Ruby ( 173196 ) on Monday April 04, 2005 @06:06PM (#12138425) Homepage Journal
      Why would we hide his posts? They're interesting, and cost me the same to read as any other (non-reg) Slashdot linked stories: nothing. That said, I would like a feature that lets us block stories by submitter on our own Slashdot pages.
    • Re:Alright (Score:1, Insightful)

      by Anonymous Coward on Monday April 04, 2005 @06:07PM (#12138434)
      It's not that we need a "Roland Piquepaille" section; it's that we need the ability to filter stories by submitter.
    • by EnronHaliburton2004 ( 815366 ) on Monday April 04, 2005 @06:13PM (#12138500) Homepage Journal
      If you're wondering why all this fuss about the Roland Piquepaille problem, check out the rpiquepa's Recently Accepted Submissions [slashdot.org].

      6 articles were submitted in the last month, NONE were rejected. If there were any Rejected articles, they would be displayed under a "Recent Submissions" section.

      What are the chances that the Slashdot editors accept 100% of Roland's submissions, when they reject the majority of submissions from other people.

      When was the last time YOU had a story accepted by the Slashdot crew?
      • by Neil Blender ( 555885 ) <neilblender@gmail.com> on Monday April 04, 2005 @06:22PM (#12138610)
        6 articles were submitted in the last month, NONE were rejected. If there were any Rejected articles, they would be displayed under a "Recent Submissions" section.

        Not true. You only see your own rejected submissions. Other people can only see your accepted submissions.
      • by Dhalka226 ( 559740 ) on Monday April 04, 2005 @06:34PM (#12138687)

        What are the chances that the Slashdot editors accept 100% of Roland's submissions, when they reject the majority of submissions from other people.

        Who cares?

        The real question is whether or not the articles he submits are worth the time of Slashdotters to read and reply to them. I'm not entirely sure what the conspiracy theory is--that he has some arrangement with the editors to accept the stories is one thing I've heard--but I frankly don't care WHO submits a story or WHERE they link it to as long as it is worth reading.

        Now, whether or not they are indeed worth reading is up for debate, but that criticism would at least be on the right track.

    • Re:Alright (Score:1, Offtopic)

      by CSMastermind ( 847625 ) <freight_train10@hotmail.com> on Monday April 04, 2005 @06:15PM (#12138519)
      In the mean time we can spread the word about what he's doing, not visit his site (I blocked it at our school) and say, "Thank you for the information, it's neat now I'm going to google the topic and find out about it".
      • Re:Alright (Score:2, Insightful)

        by Anonymous Coward on Monday April 04, 2005 @06:45PM (#12138785)
        Blocking many people's access to a web-site based on your personal opinion is censorship and is, in my opinion, a bad idea. You can educate people about what he is doing and your opinion about it, but removing other people's freedom of access to information is unethical.
    • Re:Alright (Score:5, Funny)

      by Stalyn ( 662 ) on Monday April 04, 2005 @06:21PM (#12138594) Homepage Journal
      i'll take Roland Piquepaille over Jon Katz any day.
    • by NanoGator ( 522640 ) on Monday April 04, 2005 @07:54PM (#12139325) Homepage Journal
      "Editors: GIVE HIM HIS OWN DAMN SECTION SO CAN HIDE HIS POSTS"

      That'll never happen. Every time a Roland story pops on, a bunch of twerps come in and bitch about it. For every bitch-post, there's an ad served. For every ad served, bling bling in Slashdot's pocket.

      If you guys would take off your tard hats for a moment, you'd discover that the best way to get rid of the guy is to simply stay out of his threads.
  • The future is now. (Score:5, Interesting)

    by Sheetrock ( 152993 ) on Monday April 04, 2005 @06:01PM (#12138372) Homepage Journal
    Not only for plasmonics, but for mutable instruction sets. There has been a tendency in computing innovation to withdraw to yesterday's discoveries. Tried-and-true approaches offer the twin comforts of backwards compatibility and tested reliability, attractive propositions to the modern CEO or venture capitalist savvy enough to recognize the additional benefit of recognizing further gains on already completed research. Unfortunately, and in my opinion, this follow-the-leader approach has lead to stagnation in CPU development. I'll explain using a simplified analogy for the benefit of the less technically-inclined.

    Let us think of a computer processing unit as a juggler, and bytes as mangoes. Older CPUs would juggle one mango at a time, and frequently require modifications to the stage to boot. Around the 1980s, they could juggle two mangoes. Then four around 1990, and today as many as eight at a time! Now you would be expected to be quite impressed with each leap, notwithstanding the fact that you really wanted a juggler that could handle melons, grapefruit, or watermelon slices instead of (or in addition to) mangoes. In addition, the fact that you are juggling in a zoo where a primate is free to grab your fruit and substitute twigs (or worse!) mid-juggle owing to something called "stack smashing" in computer terminology is not supposed to discourage you.

    There is a movement towards something called mutable paragraphs, where as in English "words" (groups of bytes) can be of different lengths depending on need. This may mean the ability to exactly fill out a data page for better efficiency, or to allow the CPU to work with communication protocols in their element (if a common network packet is 68 bytes long, a word should be ½NP or 34 bytes in the I/O buffer.) It also means that you use no more CPU space than you absolutely need to for a computational step, decreasing wear and tear on your components.

    I guess what I'm getting at is that science fiction has nothing on practical interative design for real world technological improvement. Sure, we might get to the same place we read about 50 years ago, but not all in one step.

  • by Neil Blender ( 555885 ) <neilblender@gmail.com> on Monday April 04, 2005 @06:02PM (#12138376)
    But they might need to rephase the modulators and run in through some sort of tachion inverter feild.
  • Heat (Score:3, Insightful)

    by TheKidWho ( 705796 ) on Monday April 04, 2005 @06:02PM (#12138387)
    How much heat are these things going to generate though. Because you know E = hf, if you have 100,000 times the frequency, your going to need to throw in 100,000 times the energy!! Of course that is simplification of what is really happening with these kinds of chips and it is much more complicated then just 100,000 times the energy needed. But it seems like these things might make the Pentium IV seems like a fridge!
    • Re:Heat (Score:3, Insightful)

      by markana ( 152984 ) on Monday April 04, 2005 @06:11PM (#12138479)
      This is why the plasma conduits in the Federation control panels keep blowing up in their faces...
    • by tanmay80 ( 864634 ) on Monday April 04, 2005 @06:14PM (#12138511)
      6.63*10^-34 * 10^5... :) not much i would guess :)
    • Re:Heat (Score:3, Funny)

      by ralphclark ( 11346 ) on Monday April 04, 2005 @06:24PM (#12138624) Journal
      Piffle! Just use a smaller value of Planck's constant! Easy. :o)
      • Re:Heat (Score:3, Insightful)

        by owlstead ( 636356 ) on Monday April 04, 2005 @08:45PM (#12139693)
        Fortune cookie for you, Mr Dallas

        The primary purpose of the DATA statement is to give names to constants;
        instead of referring to pi as 3.141592653589793 at every appearance, the
        variable PI can be given that value with a DATA statement and used instead
        of the longer form of the constant. This also simplifies modifying the
        program, should the value of pi change.
        -- FORTRAN manual for Xerox Computers
        • ...that many early ForTran compilers didn't check too closely to see if what they were assigning to was an LValue, and since a float was six bytes and a pointer to a float was 2 bytes, a compiler would typically store a copy of a constant somewhere and refer to is using the pointer, just as if it was a variable. The end result is that if you did a typoe and executed something that said:
          PI = R * R
          2 = PI
          then from that point onwards, both 2 and PI would assume the value of R squared, so if R started out being 42, then either of
          TYPE *,2
          TYPE *,PI
          would print 1764, not 2.

          If you executed 2 = 2.5 then the statement "two plus two does not equal five, even for large values of 2" would be proven false in any following code.
    • Re:Heat (Score:5, Informative)

      by barawn ( 25691 ) on Monday April 04, 2005 @06:29PM (#12138648) Homepage
      How much heat are these things going to generate though. Because you know E = hf, if you have 100,000 times the frequency, your going to need to throw in 100,000 times the energy!! Of course that is simplification of what is really happening with these kinds of chips and it is much more complicated then just 100,000 times the energy needed. But it seems like these things might make the Pentium IV seems like a fridge!

      Power does usually scale with the frequency, but it also scales with the signal strength (number of carriers: intensity in a photonic case, ~voltage in an electronic case). If you can up the frequency by a factor of two and cut the voltage (for instance) by a factor of two, it's the same power usage.

      Of course, using E = hf is completely wrong here - that's the energy of a photon, and in a completely photonic chip, wouldn't matter in the tiniest bit - because the photons are emitted at one point, and absorbed at another, so there's no net energy loss.

      Most of the places where the frequency dependence comes in are energy losses - like the resistance of a wire. With light, there's very little energy loss (in a fiber, for instance), so the chip will run very, very cool.
      • by RevRigel ( 90335 ) on Monday April 04, 2005 @07:33PM (#12139171)
        Power usage is generally linear with frequency, but proportional to the square of the voltage. Your example would use roughly half the power.
      • While I will agree there are other factors that affect a CPU, this formula does provide a bottom reference value to demonstrate that increased CPU frequency... regarless of effeciency... will always consume more energy.

        There are other fundimental constants in information theory that demonstrate a quantum effect for a single bit of data being manipulated... regardless of the effeciency of the device that is being used. There are fundimental information theory limits to how little energy can be consumed to flip that bit, and the formula of E=hf is a good place to start and try to figure out just how much energy must be used to change a one to a zero and back. The emmission and absorbtion of photons will increase entropy, and will eventually lead to a loss via emmision into the IR band. This generates heat.

        While an optic fibre is quite efficient, it will still have problems in massed quantities found in a CPU. And if the CPU clock frequency is increased to the degree claimed (100,000 times), I think the statement of the grandparent post, "A Pentium would be like a refrigerator to this CPU" is a very true statement. An optical system isn't that much better than copper or gold wires.
        • by barawn ( 25691 ) on Monday April 04, 2005 @10:40PM (#12140361) Homepage
          There are fundimental information theory limits to how little energy can be consumed to flip that bit, and the formula of E=hf is a good place to start and try to figure out just how much energy must be used to change a one to a zero and back. The emmission and absorbtion of photons will increase entropy, and will eventually lead to a loss via emmision into the IR band. This generates heat.

          Well, yes, but that energy is miniscule, even at optical frequencies. Even if you assume that it was changing a megabit of information every clock cycle for an entire second, that's still only 7 watts. And that's a processor that's well over a billion times more powerful than a modern processor. That's a perfectly efficient processor, yes, but you get the point.

          And if the CPU clock frequency is increased to the degree claimed (100,000 times)

          As I posted elsewhere, if the CPU clock frequency is that high, we're building computers out of individual atoms, which is, I believe, a harder task than dealing with dissipating 7 watts.

          The physical constant which hurts you the most at these frequencies isn't Planck's constant. It's the speed of light.
          • If we are going to get CPU speeds to Terahertz or Petahertz frequencies, I will have to agree that the physical restraints of the speed of light are going to be a very major factor with CPU designs. Also, I don't know of any physical device manufactuer who is even remotely claiming even a 1% efficiency for storage and manipulation of a bit. (That would be a huge marketing ploy if it ever were achieved.) Physical devices, even optical systems, are far less efficient than that. There is no way that they are > 100,000 times more energy efficient than conductor/semi-conductor systems if simply because it would have been done already if the savings were that substantial.

            I remember a speech by Adm. Grace Hooper where she was holding in her hands what she called microseconds, nanoseconds, and picoseconds. Basically a loop of wire that in the respective lengths of times it would take for an ideal signal to travel down that much wire. A good talk, and she was willing to give away quite a few nanoseconds, much less picoseconds. It really gets the concept of distances in small times to a perspective that your mind can grasp real easily.

            Still, even assuming that we can overcome some of the issues with FTL communication at some point in the future, Planck's constant is going to be lurking in the background ready to bite even if we are using individual quarks for gate switching.

            It is neat to see just what "hard" limits you can put on Moore's Law based on other hard physical constants from "hard science". It is also telling that electronic component manufacturers are having to get creative (such as the optical technologies being discussed in the article under discussion) in order to push systems beyond what appears to be hard limits to current manufacturing technologies.

            Something beyond a photomask on lithographed semi-conductors must be done to get another 1000x increase in CPU speeds. Manufacturers are already using X-rays to get the fine details that are needed for the device manufacturing. If the frequencies get much higher, it will move into the gamma-ray section of the EM band.
            • by barawn ( 25691 ) on Tuesday April 05, 2005 @08:01PM (#12149378) Homepage
              Also, I don't know of any physical device manufactuer who is even remotely claiming even a 1% efficiency for storage and manipulation of a bit. (That would be a huge marketing ploy if it ever were achieved.) Physical devices, even optical systems, are far less efficient than that. There is no way that they are > 100,000 times more energy efficient than conductor/semi-conductor systems if simply because it would have been done already if the savings were that substantial.

              Optical systems are orders of magnitude (maybe not 5 orders, but at least 2 or 3) more efficient than electronic ones, simply because there's no resistance and because you can multiplex signals optically rather than needing to do it electronically.

              A good talk, and she was willing to give away quite a few nanoseconds, much less picoseconds. It really gets the concept of distances in small times to a perspective that your mind can grasp real easily.

              Speed of light is a foot per nanosecond (literally: google it - it's 0.98 ft/ns), or 10 mils per picosecond. Easy enough. Incredibly useful mnemonic if you need to generate a delayed signal. "Get me 20 feet of cable, I need a clock-cycle delay." (There's a factor of 2-ish in there for the signal speed, but it's not that big a deal, and easy enough to remember).

              Still, even assuming that we can overcome some of the issues with FTL communication at some point in the future, Planck's constant is going to be lurking in the background ready to bite even if we are using individual quarks for gate switching.

              You realize that you are considering the speed of light to be a "soft" issue (as opposed to the "hard" limits from energy concerns). What makes you think that the speed of light is any less "hard" than the other concerns? Or, put another way - if we can get around the speed of light issue, I guarantee we can get around the entropic considerations (for one thing, the two aren't independent constraints).

              Something beyond a photomask on lithographed semi-conductors must be done to get another 1000x increase in CPU speeds. Manufacturers are already using X-rays to get the fine details that are needed for the device manufacturing. If the frequencies get much higher, it will move into the gamma-ray section of the EM band.

              Nah, you use non-optical methods, like electron beam lithography (which is planned). But that's all scale issues. You can't get another thousand-fold increase in CPU speeds. It's not going to happen. Another tenfold increase is not going to happen. CPU speed increases were done and through the instant you saw "drive" stages appear in the chip design to compensate for speed of light delay. They have hit the wall. The main increase in computing power at this point will come via increases in computational ability, not computational frequency.
              • You realize that you are considering the speed of light to be a "soft" issue (as opposed to the "hard" limits from energy concerns). What makes you think that the speed of light is any less "hard" than the other concerns?


                I think that FTL communication is a virtual impossibility, and some very fundimental physics reasoning must be developed to make it happen.

                I only comment about FTL communication because the U.S. Patent & Trademark Office granted a patent for FTL communication. The examiner must have flunked out of college to have approved the concept, but for the next 10-15 years such a process is patented, even if a physical impossibility. Someone (perhaps with a perpetual motion machine) must think this is possible to accomplish.
      • by PaulBu ( 473180 ) on Monday April 04, 2005 @08:01PM (#12139399) Homepage
        You ahve to charge a line with capacitance C above a certain threshold voltage V to open the transistor gate F times a second, giving you dissipated power of F*CV^2/2 just for that one line -- note V _squared_.

        Of course if you switch to superconductor logic you would not have to chagre the whole line (and there is no voltage except the instance Josephson jucntion switches), but this is a topic for another discussion.

        Other than that, yes, you are correct that you will need roughly 100,000 times more energy to run 100,000 times faster, but your energy is limited by the fact that you want to be safely above kB*T noise to switch in a non-random fashion (lowering T helps a lot ;-) ).

        Paul B.
      • by bodrell ( 665409 ) on Tuesday April 05, 2005 @12:02PM (#12144378) Journal
        Of course, using E = hf is completely wrong here - that's the energy of a photon, and in a completely photonic chip, wouldn't matter in the tiniest bit - because the photons are emitted at one point, and absorbed at another, so there's no net energy loss.
        Since that's the most intelligent remark I've seen for this story, I'm going to jack this thread. Plasmons still seem like magic to me, but I get to use the technology for something useful while electrical engineers figure out how to make plasmon computers. Biacore [biacore.com] makes surface plasmon resonance (SPR) instruments that allow you to measure surface binding. It's very cool technology; light hits a glass-covered gold, and a plasmon interacts with stuff (for example, antibodies) on the other side of the gold surface. The angle of total internal reflection changes when there is a binding event, and that angle is a measureable signal. Really nifty. Unfortunately, the instruments aren't cheap.
  • by MLopat ( 848735 ) on Monday April 04, 2005 @06:04PM (#12138408) Homepage
    Another use for this technology maybe rendering objects invisible to the observer. Using plasmons to stop light from scattering back to the observer's eyes. Unfortunately it can only be used to hide very small objects since the wave lengths of the light need to be near the size of the object that reflecting them.

    If anyone wants anymore info on this check out this link [slashdot.org].
  • Plasmonics does not sound like a perfectly cromulent word. Are you sure that the authors haven't embiggened the word a bit a bit? I mean, it's not unpossible...
  • by Valiss ( 463641 ) on Monday April 04, 2005 @06:08PM (#12138452) Homepage
    Today, plasmons can only travel a few millimeters before dying, while today's chips are typically about a centimeter across.

    Well, in that case, it sounds similar to my research. See, if you jump, you can fly. Now currently, I can only fly a foot or two. Of course, most people want to fly longer distances, but it's a start.
  • by Rightcoast ( 807751 ) on Monday April 04, 2005 @06:11PM (#12138477) Homepage
    I know next to nothing about this field but wonder if it would be possible to bridge the gap in distance using using metal or ceramic nano-wires embedded on-chip for the plasmons to travel across?
  • Wiki Free (Score:1, Interesting)

    by onyxruby ( 118189 ) <onyxrubyNO@SPAMcomcast.net> on Monday April 04, 2005 @06:11PM (#12138478)
    Is it really too much to ask for a wiki free link for reference? Articles written by the tyranny of the persistant dont tend to have much to do with reality. Really, I'm sure some school, corp, journal or industry site probably has something about this. How about a link to a google search, or something with some shred of credibility?

    Wikipedia, because the tyranny of the persistant must be right.

    • Re:Wiki Free (Score:5, Insightful)

      by kebes ( 861706 ) on Monday April 04, 2005 @06:54PM (#12138875) Journal
      As someone who posts using links to wikipedia occasionally, I must say that I object. When I'm looking for a source to explain what I'm talking about, I simply reference the best URL I can find. Very often, that is wikipedia. It doesn't really matter who hosts the data if I know it to be valid.

      As someone who has done some research on surface plasmons, I find the wikipedia article on Plasmon to be accurate and useful, so I think it is a good reference. Not all wikipedia articles are so good, but then again I don't reference the bad ones.

      On the other hand, you are pointing out that we shouldn't accept wikipedia articles just because wikipedia is cool and lots of people edited the article so it must be right. Yes, that's valid. However, as with *all* sources of information, whether it is a wiki or slashdot or an encyclopedia or the local news, the end-consumer MUST use his judgement to decide if the information is valid or BS. It is an illusion to think that traditional sources of information are error free. In all cases, the reader must simply use judgement and double-check if things seem wrong.
      • Re:Wiki Free (Score:2, Insightful)

        by LiquidCoooled ( 634315 ) on Monday April 04, 2005 @08:00PM (#12139382) Homepage Journal
        I don't think he is complaining about wikipedia in itself.
        More the fact that a person with an agenda could replace clean methodical bias free information with drivel changing the view for everyone in the process.
        The original source may not have the time or inclination to maintain his articles, so the biased view remains.

        It may be required in the long run to have a karma/points system - much like slashdot, where particular versions of articles can be rated and those written by established experts gain greater weight and visiblity.
        An outside user could view all, uncut and raw, or they can view the cream of the crop so to speak.
        • by Ungrounded Lightning ( 62228 ) on Monday April 04, 2005 @10:13PM (#12140212) Journal
          I don't think he is complaining about wikipedia in itself.
          More the fact that a person with an agenda could replace clean methodical bias free information with drivel changing the view for everyone in the process.
          The original source may not have the time or inclination to maintain his articles, so the biased view remains.


          This, by the way, is one of the things the Xanadu hypertext system was intended to prevent.

          A link-end was not just to a particular page, but a particular section of text (as small as a single byte - and if I'd had my way, a particular crack between two bytes {I have my reasons}) in the context of a particular document at a particular moment in its edit history.

          From there, if you wanted to see the "current version", you could jump to the end of the edit history. Or you could browse the (published) edit history. Or you could retrieve other documents that also included/referenced the text (those PARTICULAR bytes, not strings that were identical) in question.

          Gee. I wonder why it didn't get done and the WWW took over. B-)
  • Plasmonics? (Score:3, Funny)

    by tekrat ( 242117 ) on Monday April 04, 2005 @06:11PM (#12138487) Homepage Journal
    Wasn't that a Punk Rock Band from the 80's with Wendy O'Williams?
  • by Sebastopol ( 189276 ) on Monday April 04, 2005 @06:14PM (#12138508) Homepage
    ... is making semiconductors???

    Oh, plasMONICS... my bad...

    (I know, I know: she's deceased)
  • by loqi ( 754476 ) on Monday April 04, 2005 @06:19PM (#12138561)
    "He worked at Plasmonics Institute, just an engineer in a sealed white suit... he did a good job in the computer race, but his bosses didn't like him so they shot him into space!"
  • What the...? (Score:5, Interesting)

    by barawn ( 25691 ) on Monday April 04, 2005 @06:19PM (#12138571) Homepage
    Claiming "100,000 times the frequency" is a little misleading. You're not talking about the processor running at terahertz speeds - simply put, you can't make things small enough to do that. Plasmonic signals, photonic signals, electronic signals - they all travel on the order of light speed. There really wouldn't be much point raising the clock frequency beyond the characteristic length of the processing unit (Pentium 4 designers understand this now - they had to put "drive" stages into the pipeline just to allow signals to propagate, and that deep pipeline lead to a very low IPC).

    This would be useful for things like memory and processor interconnects, because you could shove gigantic amounts of data. Hence the reason that the article stresses their use as high-traffic freeways. I'm not sure I see the point in an all-plasmonic chip (unless they've got power advantages) because of size concerns.
    • ...overclocking his fingernail computer by swapping the green CMD (Cuticle Mount Device) LED in it for a blue one. Geeks could have nail-size competitions and "hand clusters". The mind boggles.

      With a name like that, plasmonics doesn't have to have any point as long as it also looks cool. (-:
    • by carlmenezes ( 204187 ) on Tuesday April 05, 2005 @04:12AM (#12141841) Homepage
      I get the moving lots of data around at massive speeds concept. However, how about some basic logic gate or even a transistor like functionality using plasmons? Wouldn't THAT be what would bring faster chips closer?
      I mean, having a pipe that can transport huge amounts of data at the speed of light is great, but wouldn't the feasibility of a chip depend on the capability of routing all that data based on basic logical conditions?

      Kinda like no use having a missile that can carry a million tons and fly at Mach 100 if you can't control where it goes...

      Or am I missing something here?
      • by barawn ( 25691 ) on Wednesday April 06, 2005 @09:42PM (#12161471) Homepage
        Or am I missing something here?

        The transistor speed that matters is the switching frequency (that is, how fast it can switch from a 1 to a 0, and vice versa). That's what the "GHz" means, right? OK.

        The point here is that it would be pointless to have a CPU made of transistors that switched at 100 THz (optical) frequencies. It wouldn't be faster at all.

        Why? Because that chip still has to be made of atoms, and atoms have a scale. That scale is on the order of nanometers. Let's just say 1 nanometer, to make things convenient.

        At 100 THz, a signal can only travel about 3 microns in a clock cycle. If you've got a scale of 1 nanometer, that means every processing element has to be less than 3000 elements distance in order to keep things in sync - and there's no way you can build a CPU like that - it's just not enough components.

        Scale is what limits the frequency of chips, not the method of signal propagation, and chips are very, very rapidly reaching the point where it's simply not feasible to scale anymore - not from a physical point of view, but from a signal propagation point of view.

        Anyway, that's not the big bottleneck in processors anyway. Bandwidth is. A modern CPU spends a huge amount of time stalling and waiting on data. If there's anything that can speed up that data transfer, it'll have a much larger impact than CPU speed increases.
  • by dfn5 ( 524972 ) on Monday April 04, 2005 @06:33PM (#12138680) Journal
    Today, we're using basically two ways to move data in our computers: transistors carry small amounts of data and are extremely small

    I don't know about your computer, but my computer uses wires to move data and transistors to process said data. I don't see how one can compare transistors to fiber optic cables.

  • by pyrotas ( 862419 ) on Monday April 04, 2005 @06:41PM (#12138744)
    Plasmons can be easily created in metallic nanotubes. Furthermore, it is possible to create them into an entangled state. This _in principle_ might be exploited on the quantum computation scale.
  • by technoCon ( 18339 ) on Monday April 04, 2005 @06:53PM (#12138859) Homepage Journal
    does anyone else think the term 'plasmonics' sounds like something you'd see in the movie 'Barbarella?'
  • by StimpyPimp ( 821985 ) on Monday April 04, 2005 @06:58PM (#12138912)
    "Today, plasmons can only travel a few millimeters before dying, while today's chips are typically about a centimeter across."

    Maybe its just me, but as electronics become smaller and smaller, wouldn't this be more and more possible?
  • by joey_knisch ( 804995 ) on Monday April 04, 2005 @06:59PM (#12138923)
    Hmm... Let's see...

    7 years: Develop efficient plasmonic tech.
    5 years: Create manufacturing process
    +3 years: Design cpu
    ________________________________

    15 years: Just in time for Duke Nukem Forever
  • by xeon4life ( 668430 ) <devin.devintorres@com> on Monday April 04, 2005 @07:01PM (#12138939) Homepage Journal
    You don't need a thesis, dissertation, white paper, or science magazine to tell you that the closer you put things together the faster their particles can travel.

  • by rice_burners_suck ( 243660 ) on Monday April 04, 2005 @07:37PM (#12139201)
    Nah. Forget plasmonics, fiber optics, quantum computing, and all this other junk... Let's make computers that are 100% mechanical, but built out of MEMS. Tiny gears, levers, pistons, pendulums, and other mechanisms will perform computations not previously possible with electronic computers. Better yet, let's return to the days of relay logic, but using nanotechnology to built microscopic relays. Good idea.
  • Well.. (Score:5, Informative)

    by anethema ( 99553 ) on Monday April 04, 2005 @07:54PM (#12139322) Homepage
    I havent read the article (this is slashdot after all) but the summary is terrible. (unless its the articles fault)

    From the summary:

    transistors carry small amounts of data and are extremely small, while fiber optic cables can carry huge amounts of data, but are much bigger in size.


    Transistors are just switches in the digital world. Just like anything that would be modulating the optical carrier.

    Fiber optic cables arent switches at all, or even active. You cant even compare them with transistors at all. Compare transistors maybe with an optical switch (which are ususally transistor actuated) or compare fiber optic cable with wires, but not transistors with FO cables.

    • by StateOfTheUnion ( 762194 ) on Monday April 04, 2005 @08:30PM (#12139585) Homepage
      Roland's blog is also terrible . . . It is the shameless last link in his topic.

      Plasmons are generated when, under the right conditions, light strikes a metal. The electric field of the light jiggles the electrons in the metal to the light's frequency, setting off density waves of electrons. The process is analogous to how the vibrations of the larynx jiggle molecules in the air into density waves experienced as sound.

      This analogy makes no sense because this is not analogous to how the larnyx jiggles air. The larnyx squeezes together and air is pushed through causing the larnyx to vibrate. In the case of the larnyx, the squeezing of the larnyx as air is exhaled causes flaps of tissue to vibrate . . . . How is this analogous to photons striking metal?

      A much better analogy would be how throwing a stone into a pond causes the water to vibrate. Or throwing a stone at a piece of metal causes sonic vibrations.

      Roland really should do his homework before coming up with his half baked analogies. For homework on the larnyx and how it works, he could start here [northwestern.edu].

    • by Ungrounded Lightning ( 62228 ) on Monday April 04, 2005 @10:26PM (#12140288) Journal
      Fiber optic cables arent switches at all, or even active.

      Actually, some of them are.

      One really useful example is doping the fiber with small amounts of an atom that lases in the frequency band of the light being carried. Then you wrap a bit of the fiber around a lamp giving off a suitable higer pump frequency of light. Result: A repeater amplifier. Feed it a little power and it boosts your signal.

      There are several other hacks. (At least one of them is a logic gate.)
  • by StateOfTheUnion ( 762194 ) on Monday April 04, 2005 @08:06PM (#12139434) Homepage
    Today, we're using basically (Basically is my cop-out word so that anyone that actually knows this technology can't call me out for any errors) two ways to move data in our computers: transistors carry small amounts of data and are extremely small, while fiber optic cables can carry huge amounts of data, but are much bigger in size(Actually I used the word basically because I used a terrible analogy. Transistors are used for gates and switches. Optical fiber carries information. Perhaps I should have said electrical conductors versus optical fibers, but that wouldn't sound as impressive even though its a much better analogy. But I think that most /. readers are really stupid and won't see through my gobbldey-gook. I am actually French, so you can blame it on the fact that English is not my first language.). Now, imagine a single technology combining the advantages of photonics and electronics. This Stanford University report says a new technology can do it: plasmonics.(This technology is not really new. In fact its not a technology at all. Its actually a natural phonomena, but /. readers are too stupid to know the difference. Also, its not really new either. Its been known for at least a decade . . . at least thats what this link [qub.ac.uk] form 1996 implies) (For more about plasmons, read this Wikipedia article.) Theoretically, it is possible to design plasmonic components with the same materials used today by chipmakers, but with frequencies 100,000 times greater than the ones of current microprocessors. There is still a challenge to solve before getting plasmonic chips. Today, plasmons can only travel a few millimeters before dying, while today's chips are typically about a centimeter across. Actually the articles that are linked to in the topic say that heat, connectors and other issue have to be worked out first, but /. readers can't handle more than one concept at a time, so I'm going to dumb this down for them) Read this overview for more details and references about plasmonics, and to discover why it's one possible future for chips' circuitry. (shameless plug for my blog where I'm soliciting for "premium blogads" in the upper right side of the blog. But /. readers won't notice that I have a conflict of interest and I'm trying to launch a career as a blogger/ tehcnology writer)

    Come on Roland, give us a break . . . you obviously don't understand what your writing about. Your analogies make no sense, your summarize is full of gross holes and you're trying to "sex-up" plasmons by calling a natural phonomena a technology and saying that it's something "new" when it is not. And seems you're doing this to attract hits to your blog so that you can sell ad space.

    I know this post is harsh, but I have to say that it appears that you are attempting to exploit the /. community for your own personal financial gain. We /. readers aren't as gullible or stupid as you seem to think . . .

  • by Doppler00 ( 534739 ) on Monday April 04, 2005 @10:53PM (#12140447) Homepage Journal
    I'm curious what part of a CPU they were saying was a couple cm accross. The die itself, where all the transistors are is probably less than a square CM in most cases. Given the fact that half or more of that is cache memory and the fact that most computation takes place within an area probably less than a few mm in length, it seems all they would need to do is repeat the signal every stage or so. But maybe this is why it's so difficult.

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