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Major Breakthrough In Spintronics Research 106

Posted by kdawson
from the taking-it-out-for-a-spin dept.
Invisible Pink Unicorn writes "Spintronics is the field of research into developing devices that rely on electron spin rather than electron charge to carry information. A major advance has been made by the Naval Research Laboratory (NRL), where they have for the first time generated, modulated, and electrically detected a pure spin current in silicon. Progress in this field is expected to lead to devices which provide higher performance with lower power consumption and heat dissipation. Basic research efforts at NRL and elsewhere have shown that spin angular momentum, another fundamental property of the electron, can be used to store and process information in metal and semiconductor based devices. The article abstract is available from Applied Physics Letters."
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Major Breakthrough In Spintronics Research

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  • Spintronics is the field of research into developing devices that rely on electron spin rather than electron charge to carry information.

    Yes, I believe it's called a "Phonograph".
    • by dwater (72834)
      don't tell the RIAA
    • Spintronics is the field of research into developing devices that rely on electron spin rather than electron charge to carry information.

      Yes, I believe it's called a "Phonograph".
      I'd like to see a DJ scratching on one of those.
  • Spintronics (Score:1, Funny)

    by Anonymous Coward
    All the politicians in Washington are jumping for joy for the advancement of their Spin techniques.
  • I don't get it (Score:5, Insightful)

    by Quadraginta (902985) on Wednesday December 05, 2007 @04:03AM (#21582581)
    Now, the press release says the exciting thing about "spintronics" (ugh) is that " it frees one from the constraints of capacitive time constants and resistive voltage drops and heat buildup which accompany charge motion."

    Well, fair enough; I can readily imagine that if you could get information to flow through a magical material without having to actually make electrons move, that would be great. No more of that pesky knocking into the lattice that they do which converts their motion into heat.

    But...um...how exactly do you get a spin current without the electrons actually moving? I mean, given that the spins in question are nailed to the electron? Seems tricky. Like driving down the highway without having your car move...

    Furthermore, if we read further down the abstract, we find this:

    "NRL scientists first inject a spin polarized electrical current. . . .which generates a pure spin current flowing in the opposite direction. . ."

    Sounds to me like the existence of their spin current depends on the existence of an old-fashioned charge current. So how's this help? How is this a "key enabling advance" (as the press release calls it), still less a "major breakthrough" as the /. article excitedly and credulously calls it?
    • Re: (Score:3, Insightful)

      by Tim C (15259)

      "spintronics" (ugh)
      Obviously the reasoning there is "electronics = electron + ics, therefore spintronics = spin + tronics". Which of course means that it really ought to be simply "spinics", but that sounds even worse. It's the same sort of reasoning that brings us the non-word "blogosphere", modelled on the word "atmosphere" that is actually "atmo" + "sphere" - giving the non-word you're looking for as "blogsphere", not "blogosphere"...
      • Re: (Score:3, Interesting)

        by Quadraginta (902985)
        Er, I understand the derivation. I just think it's a silly word. How would one usefully distinguish what these folks are doing -- which as far as I can see just amounts to detecting an electric current in a funky magnetic way -- from working with polarized light, which is, forsooth, detecting the spin current carried by photons? Aren't they both "spintronics?"

        I don't see the problem with "blogosphere," by the way -- the extra "o" is just added to make it roll off the tongue easier, and there's plenty of
        • by zero_offset (200586) on Wednesday December 05, 2007 @07:38AM (#21583457) Homepage
          I'm having a hard time understanding what's silly about it. You have to call it SOMETHING. What do you suggest? Spinformation? Spin-o-matics? Magnetitronics? Electrospintronics?

          At some point you just give it a name and move on.

          Although I'd still like to give the person responsible for "blog" a kick in the nuts.
          • by Whiteox (919863)
            S.A.M. Spin Access Memory (® © (TM)) is my idea!
            And I too, want to be next in line after you in giving the person responsible for "blog" a kick in the nuts.
          • Although I'd still like to give the person responsible for "blog" a kick in the nuts.
            to understand this, you have to understand Japanese abbreviations, it makes perfect sense to those who understand!
            • There is no great mystery about how "web log" became "blog", and Japanese or not (I'd have to see some evidence before I'll buy that), it's still one of the more annoying, stupid-sounding terms from the past five or ten years.

              Based on a quick Google search, I'd say you're probably completely incorrect about any connection to Japanese convention. See example below. And on the off chance that was supposed to be humorous, well, don't quit your day job. :)

              http://drweb.typepad.com/dwdomain/2005/05/what_is_the_or [typepad.com]
          • Why do I have to call it something? What's wrong with a descriptive phrase, which is what most of us call any particular area of work? What are you working on, son? Why, I'm working on spin polarization currents in conductors and semiconductors, gramps. Could be important stuff someday...

            Nice and clear, descriptive, to the point. Don't need to go get the latest jargon dictionary and look up some newfangled buzzword.
            • Re: (Score:3, Interesting)

              by zero_offset (200586)
              "Spin" itself is essentially jargon. Why not break it down into, say, quantum point source angular momentum? You could apply that same process to most of quantum physics and thoroughly eliminate the possibility of getting anything done.

              If you throw out the phrase to somebody who doesn't know what it is, then sure, you probably should have explained better, or expect to be asked for an explanation. Spintronics is a convenience. Do you really think that a bunch of researchers, who presumably work on this dail
        • Re: (Score:2, Interesting)

          by cream wobbly (1102689)
          BS on your "unobtrusive vowels". Latin psyche is from Greek psykhe, from psykhein, "breathe", from Proto-Indo European root *bhes-. In Latin, the combining form of "psyche" is "psycho-", because it's a Greek import. There is no "extra 'o'", as you put it: the vowel changed. In crypto- we see the Anglo-Latinized combining form of kryptos; again, there is no "extra 'o'", but instead the -s is elided.

          In "blogosphere", we have an unhyphenated form similar in construction to "shit-u-talk", "crap-o-matic", "tri

          • Uh...that's all very interesting and stuff, but where exactly do you actually disagree with me? As I pointed out, we adjust the spelling of words for a variety of reasons, for reasons of consistency with ancient grammar, for euphony, because pronunciation patterns shift (cf. the changes in English pronouns), and so forth and so on.

            My point was that objecting to the "o" in "blogosphere" merely because there was no pre-existing "o" in "blog" or "sphere" is overly pedantic. Do you disagree? Or are you one o
      • Re:I don't get it (Score:5, Informative)

        by counterfriction (934292) on Wednesday December 05, 2007 @05:18AM (#21582871) Homepage
        All particles have an associated spin, just as all particles have an associated net charge.
        Spintronic devices make use of the spin of electrons. Whence, Spintronics.
    • Re:I don't get it (Score:5, Interesting)

      by thatskinnyguy (1129515) on Wednesday December 05, 2007 @04:22AM (#21582659)
      Quantum Teleportation [wikipedia.org]. It's all the rage in Los Alamos.
      • Well, but this requires entanglement.
        How do you entangle billions of electrons to the 'reader'?
        How will you know which one you 'read'?
        • Re: (Score:2, Funny)

          by moogs (1003361)
          whoa, whoa, whoa, slow down here. Entanglement? Do we *really* want to open a portal to Xen? We all know what happened the last time that happened. I doubt there are enough MIT graduates with that caliber anymore... .357, wasn't it?
      • Quantum Teleportation. It's all about the range in Los Alamos.
        Fixed that for you.
    • Re:I don't get it (Score:5, Informative)

      by silverpig (814884) on Wednesday December 05, 2007 @04:44AM (#21582711)
      Spins are transferred from electron to electron as the spins flip. Imagine a series of bar magnets. You can flip one magnet and it will affect the energy of the next one, and then the next one etc. The exact solution is difficult to calculate quite often, but in general, if you have a high population of spin up electrons localized in one area, the spins will tend to diffuse away from that via a few mechanisms:

      1. The spin ups will turn to spin downs and cause nearby spin downs to turn spin up.
      2. The spin up electrons will move to the right (just picking a random direction), and this will be compensated for by having spin down move left. The result is a net spin current with no net charge current.

      To generate this, a spin polarized charge current is generally used. In this paper they used a ferromagnet contact as a source. The setup is basically a 3-way intersection.

      Lead 1 is just a floating lead not connected to any ground.
      Lead 2 is the ferromagnetic lead
      Lead 3 is a ground connection

      A voltage is applied between Lead 2 and Lead 3 causing an electrical current to flow. The electrons come out of the ferromagnet partially polarized. This current then goes into the ground Lead 3. All charge current flows from Lead 2 to Lead 3. However, the excess spin up electrons in the junction cause spins to diffuse down the floating Lead 1. No charge current flows down Lead 1 because it has nowhere to go. The result is a net spin current with no net charge current.
      • Re:I don't get it (Score:5, Interesting)

        by Quadraginta (902985) on Wednesday December 05, 2007 @04:51AM (#21582743)
        Thanks very much! Wish the PR release and abstract had been more informative.

        What's the argument for there being potentially far less dissipative losses with pure spin currents, however? It's still going to interact with the lattice via spin-orbit and spin-spin coupling terms, no? You're still going to get resistive heating, no? Is it just the fact that the magnetic dipole interactions are much shorter range interactions than the Coulomb force? (Except wouldn't it be a screened Coulomb force in the lattice anyway?)
        • Re:I don't get it (Score:5, Interesting)

          by silverpig (814884) on Wednesday December 05, 2007 @05:01AM (#21582793)
          Spin-orbit can still be quite strong yes, but it is very dependant on the material. An interesting way to think about it is that when you have a standard piece of conducting material, it's not that there is no current flowing in it while it sits there not hooked up to a source; actually the electrons go all over the place inside the material. Current flows right to left, left to right, but it all balances out and there is no net current. Resistive heating only occurs when you have net charge current. In an ideal spintronics device you would have charged currents flowing just like in any other material, but there would be no NET charge current. The spin current can diffuse along your channel. Why is this better in terms of heat? I'd have to check, but I think you're on the right track with the magnetic dipole being much weaker than an electric monopole. 1/r^4 vs 1/r^2 IIRC. One of the major benefits occurs if you can pass a coherent spin current along a channel. This leads to the possibility of quantum computations involving spins.
          • Re: (Score:3, Interesting)

            by infolib (618234)
            The difference is that there's very little energy required to flip a spin. The energy losses (at least the unavoidable ones) in computation come from deleting information, for instance to delete a single bit signified by a bunch of electrons caught in some place you'd let them flow to the ground line. If the voltage difference was, say, 2V you'd lose 2 eV per electron. If the same electrons had the bit stored in their spins, the energy you'd lose could be orders of magnitude lower, quite possible milli- or
            • by bateleur (814657)
              Although there are strict bounds on how good you can make the energy loss due to the Landauer Principle [wikipedia.org]. If we want to make really cool computers (both literally and metaphorically) we'll probably have to use stuff like Fredkin Gates [wikipedia.org].
          • by gardyloo (512791)

            An interesting way to think about it is that when you have a standard piece of conducting material, it's not that there is no current flowing in it while it sits there not hooked up to a source; actually the electrons go all over the place inside the material. Current flows right to left, left to right, but it all balances out and there is no net current. Resistive heating only occurs when you have net charge current.

            As I see it, this is a quite interesting statement, because it mixes the time scales present in the system so thoroughly. It somewhat assumes that the lattice is separate from the electrons, even at equilibrium (that is, when there is no net charge flow). In reality, the charge-carriers interact with the lattice constantly (thus not just jumping off the piece of material willy-nilly when the lattice ends at an edge, for example), and there is uniformity of energy density between the charge carriers and

          • Resistive heating only occurs when you have net charge current.

            No, wait...I don't think this is right. You get plenty of heating from eddy currents, which don't cause a net transport of charge. Plus, it's not true that there is zero charge transport going on in a conductor at equilibrium. There are plenty of thermal fluctuations in the population of electrons near the Fermi surface, and these will give rise to short-lived currents as they relax.

            However the trick, as I think someone else commented below,
    • Re: (Score:1, Informative)

      by S3D (745318)
      From wiki on spintronic [wikipedia.org] I understood there is an actual current of electrons, but with coherent spin. Kind of like laser with electrons instead of photons.
    • Re:I don't get it (Score:5, Informative)

      by brarrr (99867) on Wednesday December 05, 2007 @05:25AM (#21582895) Journal
      well, it's 1am and i'm writing up my phd thesis draft in... spintronics... so i'll jump on this as best i can, having skimmed the article (but not the press release because really, what science comes from press releases)

      the idea for spintronic devices is to use different device physics utilizing the spin of charge carriers vs just their charge. a common device is a GMR read head on hard drives - developed in '88, widespread now. the next step is to make transistors that use spin - this requires a new class of materials (GMR is a metal/macro structure effect), essentially making non-magnetic materials ferromagnetic is the goal. (personally i use ZnO, not Si, but the idea is similar). if you use a ferromagnetic semiconductor of some kind, then there is better charge transfer to other semiconductors vs a ferro metal to semiconductor... and then what you're looking for is a material that has a long spin polarization lifetime (time before the knocking around flips the spin and all of a sudden you have no polarization). so i *think* that they mean a spin current to be something that is 100% spin polarized (ie all spin up) - which means that if aligned with an applied magnetic field there will be minimal scattering therefor lower resistivity and lower heat/phonon interaction. vs. the case of a partially polarized or random spin up/down distribution where the available states in a material subjected to a field are only open to half of the free carriers (ie only spin up states are available because of the field, so only spin up electrons are efficient carriers). all this is very much so like GMR heads, obviously (well i suppose to me).

      i've met the authors at conferences, and i'm sure they're less than thrilled with this being labeled a "major breakthrough" though i'm sure they like a bit of the attention. this is pretty cool and interesting stuff that they've done, but it isn't a breakthrough - just another piece of an extremely large and complex puzzle.
      • Re: (Score:3, Interesting)

        by zero_offset (200586)
        The "major breakthrough" label was only used in the slashdot article... not exactly anything to get worked up about...
      • by tgd (2822) on Wednesday December 05, 2007 @09:02AM (#21583891)
        I'm sorry, I'm going to have to ask you to leave. This is Slashdot and we don't take kindly to people who actually know what they're talking about around here...
      • (but not the press release because really, what science comes from press releases)

        That's odd... I thought press releases were all about spin.
      • by silverpig (814884)
        A spin current does not need to be 100% polarized, and I'm pretty sure this one is not. The spin currents from ferromagnetic sources have a relatively low polarization. QPCs are much better. All you need for a pure spin current is transfer of angular momentum in some direction without a net transfer of charge.
    • Re: (Score:1, Interesting)

      by Anonymous Coward

      But...um...how exactly do you get a spin current without the electrons actually moving? I mean, given that the spins in question are nailed to the electron? Seems tricky. Like driving down the highway without having your car move...

      All cars in existence cover every road, and any given passenger will stand atop their car dancing. All dancing passengers avoid doing the same dance as any other; that'd be embarrasing. The interference between dancers will reach the destination.

      Or, just imagine an infinitely high frequency alternating current.

    • by JSchoeck (969798)
      Neighboring spins influence each other (see also Nuclear Magnetic Resonance spectroscopy), so indeed there can be information transported.

      Probably what they mean when talking about current is that you need a lower current or they believe that it's possible to optimize the process to increase transmitted information while not increasing current.

    • I think the current is mostly marketing spin.
    • by vertinox (846076)
      But...um...how exactly do you get a spin current without the electrons actually moving? I mean, given that the spins in question are nailed to the electron? Seems tricky. Like driving down the highway without having your car move...

      Correct me if I'm wrong, but I thought the whole point was not to prevent electrons from moving but to have more information storage on an electron which means you would need less of them to transmit more data.

      Right now the way CPUs work on that level is either on (electron movin
      • by atrizzah (532135)
        I'm too drunk to explain, but you have it all wrong. All of it. Please look up CMOS on wikipedia or something
    • But...um...how exactly do you get a spin current without the electrons actually moving?

      The same way you get a crowd at a football game to do the wave without anyone moving over a seat.

      "NRL scientists first inject a spin polarized electrical current. . . .which generates a pure spin current flowing in the opposite direction. . ."

      I can't say for sure, but I think this may be incidental to the experimental setup, and not a fundemental restraint on the spin current. Also, this electrical current might be

    • Ok, in standard electronics we have to turn on/off a signal everytime we want to send information. This takes time, uses extra power, and generates extra heat (mostly from the fact that the wire the signal is going down has a capacitence that needs to be charged before the signal can be complete).

      The capacitence of these wires is miniscule because the wires are so small but in a modern computer the signal may be turning on/off billions of times a second so it does add up. If I remember correctly it comes
    • by bsalus01 (970576)
      the spin of an electron is an intrinsic property. it doesn't actually mean that the electron is spinning. an particle's spin is the angular momentum of its magnetic field. an electron can have a spin of 1/2 or -1/2.

      so it can stay stationary and the chip can just change the spin to, for example, 1/2 for a 1 and -1/2 for a 0.
    • by ChatHuant (801522)
      But...um...how exactly do you get a spin current without the electrons actually moving? I mean, given that the spins in question are nailed to the electron?

      Quite easily, actually. Use some mechanism (magnetic fields in the FA) to force an electron's spin to align to a neighboring one, then align the next one, and so on. You get a spin wave travelling through your medium, but the actual electrons don't move.
  • Oh man (Score:1, Funny)

    by Kelz (611260)
    This must really scare Bill O'Reilly.
  • by Anonymous Coward
    This sounds like the type of thing that will work under laboratory vacuum conditions, but which
    we are decades away from being able to implement usefully for any real world application.

    Since they are using the angular momentum of electrons to register as a voltage for recognition,
    how susceptible to interference is such a system? I would imagine simply shining a flashlight
    on such a quantum circuit would affect the resultant output... unless I'm way off.

    Any microminds care to shed some light on this?
    • by infolib (618234) on Wednesday December 05, 2007 @06:48AM (#21583215)
      Well, I'm not a particle physicist either, but I did my master's thesis on this type of system(*) So, how close are they to applications?

      First of all, they've measured from 5K up to 80K which is about quarter of room temperature, practically there by solid state physics standards (see the Nature paper). Considering that the effect didn't dwindle by more than half in that range, that's a very good sign that it could be brought up to room temperature. The problem is in getting the electrons "lined up" enough. In the Nature paper they estimate that they see about 30% more spin up than down electrons, but for real applications you'd like to get a lot closer to "100% polarization". I guess that problem might be solvable, but it includes a lot of putting very thin layers of material on single crystal with quite extreme tolerances. Then again, chip fab tolerances are quite extreme already.

      In cases like this it's hard to figure out how well stuff will work without actually trying, and that's what this recent paper is about: They've built a transistor-like device with technology similar to that which would be used for mass production and measured a (tiny) effect. Now it's a matter of optimisation, and they might just get there, but it'll be years at least before it's time to start drafting the chip layout.

      (*) Hint: If it involves building huge accelerators to crash particles together at pseudo-Big-Bang conditions, it's particle physics. If it involves sticking little pieces of semiconductor into a magnet at 5 Kelvin it's solid state physics. Not that solid state physicists don't use particles, we're all over electrons, phonons, excitons, magnons and many other 'ons that ignorants dismiss as "quasi"particles. Hrmph!
      • Ah, so as someone academically qualified to discuss xons in general, is there indeed such a mathematical object as a 'spintron,' or is this another case of a journalist and/or PR person who doesn't have a clue about the atomic structure of language?
        • by infolib (618234)
          No, I've never heard of spintrons. I think it's just a construction to sound like electronics while implying that it's about spin. I don't know who invented the term, but I don't mind it - it's relatively descriptive after all, and it's used in a number of scientific articles. The one problem might be that it can become a bit over-hyped, but in general too few people know about it for that to be a problem.
          • I think what I resent about it is that I now need to allocate two new slots in my mental lexicon—one for "spintronics" (ok, fine, it's a new concept) and one for "-tron-" (but meaning what, exactly?). If they want a catchy new word, why not just call it something new, like 'flarp', or something more regularly derived, like 'spinics' (still an abomination in classical terms, but far more structurally resonable)?

            I wish all these PhD-types would go to school, or something! ;)

  • by Bones3D_mac (324952) on Wednesday December 05, 2007 @04:38AM (#21582697)
    For some reason, the term "spintronics" makes me think of it as though this was a long series of ball bearings in physical contact with the adjacent ones, and using the rotational force of the starting point to rotate each ball bearing in an opposite direction as the ones they're in physical contact with... eventually transferring the rotation to the end point.

    Is it simply a case that in spintronics that the electrons used to carry a current don't actually leave their respective atoms (as they do in AC and DC current), but are just being rotated faster/slower or alternating direction?
    • Re: (Score:2, Informative)

      by Anonymous Coward
      Spin is detected with quantum effects. See for example, the Giant magnetoresistance effect: http://en.wikipedia.org/wiki/GMR_(physics) [wikipedia.org]
      • Thanks!

        With any luck, this won't be something consumers will have to decipher off the back of a box anytime soon. The name raises more questions than it answers. :-P
    • by infolib (618234)
      That's actually not so bad a picture, since it's about transferring and controlling angular momentum rather than charge. But the electrons do in fact leave their atoms. In this respect it's better to think of them as waves: They form waves filling out the entire material, it's just that the wave directions all cancel out until you apply a voltage. That also allows them to transfer their angular momentum to each other better, since the magnetic interaction between two electrons sitting isolated from each oth
      • Wow, I actually wasn't entirely serious about the ball-bearing anology, but if it works as a primitive visual aid, it kind of makes you wonder what something as complex as a spintronic integrated circuit would look like. Would it be something akin to a complex system of "ball bearings" and "clutches" controlling one another?
        • (Additional sidenote to the ball-bearing IC... probably way off into an unrelated tangent.)

          It occured to me that "spin" in this sense isn't constrained to following only linear/planar paths. Instead, you could simply "snake" the rotational force in any direction so long as the bearings along the path remain in physical contact from start to end. For example, take a cube matrix of these ball bearings where you can change the path a specific spin could follow. When the rotational force travels horizontally al
  • by Anonymous Coward on Wednesday December 05, 2007 @04:50AM (#21582735)
    The same has been achieved in GaAs some time ago: http://www.nature.com/nphys/journal/v3/n3/abs/nphys543.html [nature.com], and the article at http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=APPLAB000091000007072513000001&idtype=cvips&gifs=yes [aip.org] (if you are subscribed) says:

    Electrical spin injection and detection have been demonstrated in all-metal devices [4,5] and ferromagnet/semiconductor based spin valves [6-8] having distinct coercivity difference between ferromagnetic spin injectors and detectors.
  • by Anonymous Coward
    Humanity will be unstoppable once we have invented these phase converters to modulate!
  • but I'm trying to figure out how this can be applied to our current electronic designs. If we use electron spin to store data, and presuming that we can determine which way it's spinning, then that gives us a total of six possibilities, right?
    +pitch -pitch +yaw -yaw +roll -roll
    Or, of course, this could be denoted as 0 and 1 instead of + and -. However, doesn't that throw out the current binary model? This'll effectively be base six, instead of base two, won't it?
    I dunno - this isn't exactly my field,
    • by infolib (618234) on Wednesday December 05, 2007 @06:11AM (#21583065)
      No, it's a quantum mechanical thing. Seeing spin as the electron spinning is a very intuitive picture, but also quite wrong. The real understanding of spin involves stuff like non-commuting operators that I won't go into here (and a quantum mechanics textbook will probably do it better) but the upshot is:

      A single spin 1/2 particle like an electron can be in two states. You can measure the spin along x, y or z direction as you wish, and the answer will always come out to either plus or minus hbar/2. (hbar is the reduced Planck's constant).

      It's with this spin like momentum and position: You can't know both at once. If you measure a certain spin along x, the spin in y and z directions will be in a Schrödinger's cat like state: Both + and - at once, but if you measure it you'll only see one. Of course you can choose an axis very close the original x, and you'll be very likely (but not sure) to measure the same general direction.

      In sum, the easy thing to do with a spin is to treat it like a single bit, just pic one direction and measure along that. (For computer operation you'd probably like using 10-10000 spins at once to limit the effects of noise, just like transistors aren't quite reliable using a single electron (yet)). If you're into the advanced stuff you can have the spin hold one qubit (google it) and do quantum computation, but the technology in this particular report is likely to stay on the classical side.
    • Electrons (like other fermions and subatomic particles) behave according to quantum mechanical rules, not the classical rules we are used to. Quantum mechanics says that electrons a have half-integer spin, which means that their spin can either point up or down (+z or -z). So they can pitch but they can't yaw or roll. So this suits binary computing very nicely.
    • Well, glad that I got an (unintended) laugh there, at least...
      Thanks for the answers though, guys. I appreciate it. I come from a graphics background, so I think in terms of 3D graphics, not advanced semi-theoretical physics...
  • Sounds like a silly question, I know, but I seem to recall that when talking about the "spin" of fundamental particles, you aren't really talking about the same thing as when you're talking about the spin of a baseball. Can anyone confirm/clarify this?
    • by gravisan (1179923)
      isn't this really quantum computing ? ...why do we need a new title for it?
      • by amb1978 (1147995)
        Spin is a quantum property of electrons, so in some sense, it can be used to store quantum information. However, spintronics is (for the time being) looking at another direction. For quantum information you want to look at the state of a single spin, not a whole bunch of them rolling down a wire, 'cause then you loose the essential quantum-cool-features.
      • by xtieburn (906792)
        No, spintronics is the use of a particle properties to improve what we already have. I.e. faster more efficient transistors.
        Quantum computing is the use of particle properties to produce a powerful third state so instead of 1 and 0 you get 1, 0 and both.

        Though they do both require physics at the quantum level it would be confusing to lump it all under the same name when they are very different technologies. (There is a lot of confusion with regard to quantum processors already.)
    • I seem to recall that when talking about the "spin" of fundamental particles, you aren't really talking about the same thing as when you're talking about the spin of a baseball.

      I have heard that too. It is not clear to me what the distinction is, other than maybe the idea that "spin" is often visualized as a straight line spinning around its midpoint, so the endpoints of the line are going in a circle, and the angular momentum is easy to see as related to the length of the line; but if the length of

  • Is there ANY discipline that some slashdotter doesn't have a Ph.D. in?
  • by Anonymous Coward
    As a graduate student who studies semiconductor spintronics, I'd have a hard time calling this a major breakthrough. It's an interesting paper, but it basically adds incrementally to previous work involving spins in silicon. In particular, see references [10] and [11] in the APL article. Reference [10] was the first paper to demonstrate spin transport in silicon and was published in an issue of Nature. See: dx.doi.org/10.1038/nnano.2007.174

    I'd like to add that the farther along in my science career I've
  • Wouldn't spinning the electrons faster cause the atom to move into a higher energy state? (Plasma?) /I'll take one in the 40 Megawatt range......
  • That a law suit has just been filed in east Texas.
  • by kooky45 (785515)
    It looks like you're reading a quantum state. Do you wish to continue? Yes/No? No/Yes?
  • Dizzy (Score:4, Funny)

    by ravensee (1174365) <ravensee@gmai l . c om> on Wednesday December 05, 2007 @09:39AM (#21584095)
    We must move forward, not backward. Upward, not forward. And always twirling, twirling, twirling.

Numeric stability is probably not all that important when you're guessing.

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