Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×
Science

Physicists Detect Elusive Orbiton By "Splitting" Electron 131

ananyo writes "Condensed-matter physicists have managed to detect the third constituent of an electron — its 'orbiton'. Isolated electrons cannot be split into smaller components, earning them the designation of a fundamental particle. But in the 1980s, physicists predicted that electrons in a one-dimensional chain of atoms could be split into three quasiparticles: a 'holon' carrying the electron's charge, a 'spinon' carrying its spin and an 'orbiton' carrying its orbital location. In 1996, physicists split an electron into a holon and spinon. Now, van den Brink and his colleagues have broken an electron into an orbiton and a spinon (abstract). Orbitons could also aid the quest to build a quantum computer — one stumbling block has been that quantum effects are typically destroyed before calculations can be performed. But as orbital transitions are extremely fast, encoding information in orbitons could be one way to overcome that hurdle."
This discussion has been archived. No new comments can be posted.

Physicists Detect Elusive Orbiton By "Splitting" Electron

Comments Filter:
  • Fantasy (Score:5, Funny)

    by countach ( 534280 ) on Thursday April 19, 2012 @12:45AM (#39731415)

    Let's face it... the particle physicists make all this stuff up. Somehow they figured out how to use particle colliders to synthesise crack cocaine, and ever since then the stuff they've been coming out with has been ever more fantastical.

    • Re:Fantasy (Score:5, Interesting)

      by Anonymous Coward on Thursday April 19, 2012 @02:22AM (#39731689)

      Play snarxiv versus arxiv: http://snarxiv.org/ [snarxiv.org] , where computer generated article titles compete with real ones.

      • Thanks for pointing this out, I'm a particle physicist and this was good for a laugh. That said I will admit to feeling a certain amount of relief when I played snarXiv vs. arXiv and was 10 for 10. There are days when you wonder if some random paper you are reading is just a string of meaningless words.

      • by Anonymous Coward

        (Honestly not the same AC): WTF is up with you mods? Snarxiv is hardly a troll website, and neither is pointing it out in this context. (Hint: It was made by a HEP theory researcher, poking a bit of fun at his own field -- it's the kind of thing Human Beings like to do sometimes...)

        • by Khyber ( 864651 )

          It's modded troll because the people with moderator points are fucking morons.

          You needed any other explanation?

    • magic mushroom particles
    • by Ihmhi ( 1206036 )

      Man how am I even supposed to take chemistry or physics classes you guys. I cannot draw dots this tiny! PLEASE STOP DISCOVERING SHIT!

    • Let's face it... the particle physicists make all this stuff up. Somehow they figured out how to use particle colliders to synthesise crack cocaine, and ever since then the stuff they've been coming out with has been ever more fantastical.

      Cocaine? Nah, it has to be lsd that they synthesised.

    • Magnets.
    • I'm not sure about crack cocaine...but I've heard that they use these colliders to generate a significant amount of speed.

  • Reading stuff like this makes me wish I'd taken more a lot more science in college, maybe went for an entirely different degree. Because honestly I've no idea what they are talking about. If anyone could possibly explain this a bit more I'd be really very happy.
    • It sounds like they "split" it on paper, mathematically separating the characteristics so they can do computations with them.

      I didn't read beyond the summary though, I came in to the comments section looking for confirmation of my theory from a smarter commenter than myself.

    • Re:Sigh (Score:5, Informative)

      by Anonymous Coward on Thursday April 19, 2012 @01:11AM (#39731491)

      The article is talking about quasiparticles, that is, collective excitations in some medium that behave as though they were individual particles. Think about a Newton's cradle (that thingy with the balls that click back and forth). When a ball hits one end of the device, a ball emerges from the other end of the device. It's as though there were some kind of particle (there's a mandatory rule that we have to give it a stupid name, so let's call it a ballon) that is transmitted through the device. Now, even though we know that there's no actual particle traveling through the device, we can make calculations as though there were, and this makes things simpler to work with.

      Condensed matter physicists work with much more complicated media and their particles are quantum rather than classical, but otherwise the idea is the same. In this case, they have a medium consisting of a strontium cuprate wire, which, of course has lots of electrons in its atoms. They fire a beam at it (like the ball hitting the Newton's cradle) and this excites stuff in the wire, which they find acts like quasiparticles of a particular kind.

      The exact kind of quasiparticle is one that acts like an electron, but has no charge or spin, just orbital properties. The spin and charge kinds of quasiparticle were previously discovered, and this completes the set, which is why it's news.

      • Thanks - the analogy is actually pretty helpful.
      • Re:Sigh (Score:5, Insightful)

        by Grayhand ( 2610049 ) on Thursday April 19, 2012 @03:02AM (#39731821)
        Glad some one else brought this up. Naming the states and calling them particles is a little like saying three dimensions are three particles. Shouldn't there be a particle for height, width, depth? At a certain stage it's pointless naming to rationalize publishing a paper. Is dividing an electron proving multiple particles or is it in fact like splitting a glass of water and claiming that it's two new atoms? And yes I know there are two atoms making up a glass of water so in this case it would mean four atoms since you can divide a glass of water in half. Unless unique properties can be established for the resulting two electrons then you haven't found two new particles you have simply split a single particle in to two pieces.
        • Shouldn't there be a particle for height, width, depth?

          Well, we already have up & down quarks.

        • Give a short, complete, accurate answer to this question: what is a particle?

          If you must be ignorant, keep an open mind. Outside of the scale that human senses are designed to appreciate, extrapolation from experience tends not to be very useful.

        • I think to a degree you are right. But there is a great deal to physics which as much imagination and wimsey as there is evidence to support it. But when you start to take the macro view and say it's the study of everything then naming becomes important. Considering the orbiting characteristics of an electron are suspected to be unknown. As mentioned in later comments the idea that you can't know where it is until you measure it and thereby change it's path making it impossible to know where it's going

          • Re:Sigh (Score:5, Informative)

            by slew ( 2918 ) on Thursday April 19, 2012 @10:04AM (#39734071)

            Unfortunatly, they didn't select my submission [slashdot.org], but the idea is basically unbound electrons have some quantum numbers related to spin and charge, but electrons bound to a nucleus have another quantum property related to the orbital they exist in (as a result of all those pesky electron orbital exclusion properties we get a taste of in chemistry 101). This gives the electron a sort of angular momentum quantum property (that is angular momentum isn't a continuous property, but is quantized to certain discrete values).

            You might imagine that in the classical sense, if you bumped an electron out of orbiting one nucleus and it be bound to the next nucleus in a lattice, the idea of what angular momentum all the electrons had would be somehow be conserved as a whole in the system on average. Now you toss in the fact that in a lattice, these otherwize local effects of virtually exchanging angular momentum might become delocalized from their actual particles and still maintain the required system average and also (in certain circumstance) still reveal their orignal quantum nature (instead of continuous approximation), that's the effect you have. It isn't a real particle exhibiting quantum effects, but a quasi-particle, but in some sense we've split-off the angular momentum effect from the actual electron that is bound (w/o unbinding the electron).

            If you are familiar with semiconductors, you can often hear of people talking about "holes" conducting electric charge like they are electrons, but they aren't electrons: it's a "hole" in a sea of delocalized electrons doing that charge transport. Usually the effects we are interested in are quite classical (say like average current), but in smaller dimensions and lower energy levels we start exhibiting quantum effects of these quasi-particles (say like in supercondutors).

            I don't know how this orbiton angular momentum thing will be useable. The effect that was observed was that excitation to higher orbits (higher angular momentums), can propagate in the lattice which seems less useful (eventually you are in such a high excitation energy, you are beyond most interesting quantum effects or effectively unbound). One speculation that I have is that certain insulator properties will be quantized (if certain orbits are unavailable, and the incoming quantum angular momentum is incompatible with the available orbits), and maybe that can be used for some storage capabiltiy or maybe somehow helping spintronics (which is sort of what these folks were thinking).

            Hope that helps a bit...

        • Shouldn't there be a particle for height, width, depth?

          Yeah, they exist, but they are in the realm of mathematicians, not particle physicists. Specifically in the mathematical subdomain of analytical geometry, where these particles are typically called "vectors". Any complex vector of arbitrary direction and length has been shown to be composed of three elemental vectors that, in informal discussions, are called "taller", "wider", and "thicker". (And there are also the anti-elementals of "shorter", "narrower", and "thinner"). It is conjectured that these elemen

        • Using the word "particle" indicates a particular set of characteristics familiar to physicists. Frankly, most of the short-lived particles that high-energy Physicists work with are really just states with certain characteristics. Guess what? In quantum theory what most people would call "actual particles" are "just states." It's turtles all the way down.

      • Re:Sigh (Score:5, Informative)

        by mathfeel ( 937008 ) on Thursday April 19, 2012 @04:09AM (#39732113)

        The article is talking about quasiparticles, that is, collective excitations in some medium that behave as though they were individual particles. Think about a Newton's cradle (that thingy with the balls that click back and forth). When a ball hits one end of the device, a ball emerges from the other end of the device. It's as though there were some kind of particle (there's a mandatory rule that we have to give it a stupid name, so let's call it a ballon) that is transmitted through the device. Now, even though we know that there's no actual particle traveling through the device, we can make calculations as though there were, and this makes things simpler to work with.

        Condensed matter physicists work with much more complicated media and their particles are quantum rather than classical, but otherwise the idea is the same. In this case, they have a medium consisting of a strontium cuprate wire, which, of course has lots of electrons in its atoms. They fire a beam at it (like the ball hitting the Newton's cradle) and this excites stuff in the wire, which they find acts like quasiparticles of a particular kind.

        The exact kind of quasiparticle is one that acts like an electron, but has no charge or spin, just orbital properties. The spin and charge kinds of quasiparticle were previously discovered, and this completes the set, which is why it's news.

        More specifically, "separation" refers to the prediction (and now observation) that in the collection of electrons in the 1D wire, orbital, spin, and charge information travel at different speed. This is in particular a low dimensional effect. Hence this is observed in a quantum wire.

      • dammit... now i want a ball clicky thing
      • by AlecC ( 512609 )

        Thank you. I think you just stopped my brain melting. I now have a smidgeon of a fragment of a trace of a clue what the article is about.

      • Philosophically, what makes these particles any more quasi- than electrons? Surely all we have to work with is the sum of their effects in either case.
        • Re: (Score:2, Insightful)

          by Anonymous Coward

          Philosophically, what makes these particles any more quasi- than electrons? Surely all we have to work with is the sum of their effects in either case.

          It's the medium. When you look at a quasiparticle, it only exists in the context of its medium, whereas fundamental particles exist in the vacuum. It's a bit like the difference between sound waves and light waves. A sound wave needs something to wave in; a light wave doesn't. Or at least, if it does, the thing it waves is omnipresent throughout the universe and obeys the peculiar laws of relativity; that makes it seem pretty special, doesn't it?

      • But if they didn't actually split a particle the article is misleading.

        Why can't scientists review their press coverage?

      • Think about a Newton's cradle (that thingy with the balls that click back and forth). When a ball hits one end of the device, a ball emerges from the other end of the device. It's as though there were some kind of particle (there's a mandatory rule that we have to give it a stupid name, so let's call it a ballon) that is transmitted through the device.

        If I understand the physics of this phenomenon properly (not guaranteed), the "particles" transmitted thru the system of balls already have a name: phonons [wikipedia.org].

      • by kwoff ( 516741 )

        Another example of quasi-particles are phonons [wikipedia.org]. Maybe easier to understand. Phonon makes you think of sound (phonograph). What is sound? It's waves of compression of air molecules. Sound can travel through solids, too, in which case it's waves of compression of the molecules in the solid. Imagine you have a lattice (regular array) of molecules, like a solid crystal, and you tap it on one side. Where you tap, it will push the molecules closer to other molecules, and those will push away other molecules, whic

  • Can someone actually explain this? I am trying to get my head around a one-dimensional anything ...
    • by kava_kicks ( 727490 ) on Thursday April 19, 2012 @01:03AM (#39731465)
      Wikipedia says this about Mott insulators: Mott insulators are a class of materials that should conduct electricity under conventional band theories, but are insulators when measured (particularly at low temperatures). This effect is due to electron-electron interactions which are not considered in conventional band theory.
    • by Y.A.A.P. ( 1252040 ) on Thursday April 19, 2012 @01:33AM (#39731559)

      I believe you're over-thinking the one-dimensional attribute. It simply means they're using a straight-line chain of the molecules in question. There are no molecules in the construct branching off at any other angle, that's all.

      • by mathfeel ( 937008 ) on Thursday April 19, 2012 @04:12AM (#39732117)

        I believe you're over-thinking the one-dimensional attribute. It simply means they're using a straight-line chain of the molecules in question. There are no molecules in the construct branching off at any other angle, that's all.

        Charge-spin separation and spin-orbital separation are specifically effect of electron collective behavior in one-dimension: that is when the motion of electron is constrained to have one degree of freedom. Think of a single-lane road in which lane change is forbidden.

      • Thanks.
    • i have trouble understanding politicians too.

    • by Anonymous Coward

      All I know I know is that they are NOT FUNNY [slashdot.org].

    • There's a good one in a previous comment thread above here [slashdot.org].
    • by Anonymous Coward on Thursday April 19, 2012 @03:21AM (#39731895)

      Imagine a long chain of molecules, so that the electrons jump from orbiting one molecule to another along a 1D path.

      A Mott Insulator is an insulator (ie it doesn't conduct electricity), but one that is caused by interactions between electrons. In an ordinary insulator (a 'band insulator') doesnt conduct electricity because there are simply no available orbital states for the electrons to move into. Imagine a series of boxes, with electrons as balls moving from one box to another. In a band insulator the boxes are full, so you simply can't move the balls around. In a Mott insulator however, the boxes are plenty big enough but the interactions between the electrons (balls) are strong enough that you can't put more than one ball in each box. So you end up with one ball per box and nothing can move.

  • I think the 'heaviest' particle should be deemed the Megatron, in keeping with the WTFatron naming convention.

  • by Anonymous Coward on Thursday April 19, 2012 @02:45AM (#39731759)

    ..it is called a "holdon".

    As in; hold on, we better check these results again.

  • These physicists need to back off the horny goat wee.
  • I'm sorry, but every little half-understood news blurb regarding particle or condensed matter physics, or spintronics or lasers or topological insulators or what-ever, "could also aid the quest to build a quantum computer". That's a total blarney. Could we just admit that we don't really know an practicable way to build a useful quantum computer yet, and leave it at that?

  • Where does the charge go?

"I shall expect a chemical cure for psychopathic behavior by 10 A.M. tomorrow, or I'll have your guts for spaghetti." -- a comic panel by Cotham

Working...