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News Science

Majorana Fermion May Have Been Spotted At TU Delft 73

Posted by Unknown Lamer from the secrets-of-the-universe dept.
vikingpower writes "A research group at Technical University Delft around prof. Kouwenhoven has probably not only spotted pairs of so-called Majorana Fermions for the first time (these had been predicted to exist by the Italian physicist Ettore Majorana), but also demonstrated that, by generating them at the end of an Indium-Arsenide microwire, quantum computing with them may have come one more step closer to reality. The excitement around Prof. Kouwenhoven at the American Physical Society annual congress in Boston, after he completed his presentation, was considerable.A nice illustration is provided by this newspaper article (in Dutch)."
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Majorana Fermion May Have Been Spotted At TU Delft More

Majorana Fermion May Have Been Spotted At TU Delft

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  • Realized halfway through the summary... (Score:5, Funny)

    by Anonymous Coward on Thursday March 01, 2012 @03:08PM (#39213423)

    It didn't say Marijuana

  • What? (Score:2, Funny)

    by bhcompy ( 1877290 )
    Is that the female orgasm or something?

    • Re: (Score:1, Funny)

      by Anonymous Coward

      Is that the female orgasm or something?

      How many times do I have to tell you... most women aren't physically attracted to high energy physics experiments like you are!

      • Perhaps, but there are some women I'd still love to perform "high energy physics experiments" with, any night of the year. ;)

  • Picture label wrong, it's indium-antimonide, (Score:3, Insightful)

    by Anonymous Coward on Thursday March 01, 2012 @03:18PM (#39213559)

    The picture and article differ in the wire composition, so which is it?
    indium-antimonide or indium-arsenide?

  • I like to think that I have an okay understanding of how my computer works. When quantum computing becomes mainstream a computer will truly be a mystical device with magical power, but I'll still just use mine to play sudoku while I'm on the bus.

    • Any sufficiently advanced technology is indistinguishable from magic. But it is not magic.

      Moral of the story?
      There is no such thing as magic.

      • Any cool ass magic will be indistinguishable from sufficiently advanced technology.

      • Re: (Score:2, Insightful)

        by Obfuscant ( 592200 )

        Any sufficiently advanced technology is indistinguishable from magic. But it is not magic. Moral of the story? There is no such thing as magic.

        "All A is B" does not prove "All B is A".

        The fact that you might find some advanced technology that will allow you to turn water into wine doesn't mean that when I do it it isn't magic, only that when YOU do it it isn't. Magic is the process, not the end result.

        There is currently technology that will take elemental carbon and produce diamonds in the laboratory. That doesn't mean that every diamond on the planet was produced in a laboratory.

        • Re:Now why didn't I think of that? (Score:5, Funny)

          by jackbird ( 721605 ) on Thursday March 01, 2012 @08:10PM (#39216357)

          Are you saying the other ones were formed by magic?

        • Re: (Score:2)

          by geekoid ( 135745 )

          Wrong. In fact,. that was a pretty lame way to try and support and incorrect assumption in the quote.

          I can' look at technology I don't understand and know it isn't magic.

          "That doesn't mean that every diamond on the planet was produced in a laboratory."
          true but they weren't produced by magic.

          • true but they weren't produced by magic.

            I didn't say they were. What I said is that the existance of a "sufficiently advanced technology" doesn't prove that diamonds cannot be produced in any other way. Diamonds are an example not because I think they are produced by "magic", but because the technological source doesn't prove anything about any other source in such an obvious way that I didn't think I'd have to answer ridiculous claims that I thought they were all magic.

  • Condensed Matter (Score:5, Informative)

    by tylersoze ( 789256 ) on Thursday March 01, 2012 @03:42PM (#39213829)

    Note we're talking about condensed matter physics here, so this isn't the discovery of a fundamental particle that is a Majorana fermion, just a composite particle (similar to a Cooper pair) that appears to behave like a Majorana fermion. I'm sure this is an exciting discovery, but I tend to get more excited about fundamental particle discoveries.

    BTW, maybe someone can enlighten me further, but since neutrinos have mass wouldn't they probably have to be Majorana fermion? You could catch up to a neutrino and make it appear as right-handed in some reference frame which would presumably make it's anti-matter right-handed counterpart? Neutrinoless double-beta decay is what would confirm that, right?

    • Re: (Score:1)

      by Anonymous Coward

      Yes, neutinoless double-beta decay is the smoking gun for Majorana neutrinos. However, there is no good theoretical reason for neutrinos to be Majorana; they should be Dirac particles, just like every other fermion in existence. It's one of those things that isn't ruled out by experiment yet and gets certain kinds of model-builders all excited.

      On the one hand, everybody thought parity was a good symmetry when P-breaking was not ruled out by experiment, and the discover of parity-breaking was fundamental to

    • Yeah I was wondering why I was seeing this first on Slashdot before any of the particle blogs.

    • They cold be a Dirac fermion with sterile right-handed counterparts. You can even make the mass of the right-handed neutrinos different: Seesaw Mechanism [wikipedia.org].

  • not a real elementary particle (Score:3, Informative)

    by Anonymous Coward on Thursday March 01, 2012 @03:44PM (#39213853)

    This is not a discovery of real elementary particle, instead it is a quasiparticle. It behaves (in its quantum properties) like Majorana Fermions, much in the same way a "hole" in a semiconductor behaves like a positively charged particle.

  • Was the FBI in time... (Score:1)

    by Anonymous Coward

    ...to arrest that bitch...?

  • 4-1 (Score:1)

    by Anonymous Coward

    An automatically scheduled press release and someone mistyped: '4' and '3' are rather close on a keyboard.

    The hole thing reads like an April's fools joke. Tell me this ain't so.

  • How the hell did Delft get ME3 ahead of the rest of us? What are Majorana's loyalty mission and romance options?

  • I honestly read it as, "Marijuana Majorana Fermion May..." not "Majorana Fermion May..."

    Too much on my mind, I guess.

  • for most /.ers... (Score:1)

    by Anonymous Coward

    this is probably the first time they heard of Majorana Fermions. In a bit you'll see visits to wikipedia spiking and suddenly everyone's an expert on Majorana Fermions. For the rest who can't be bothered to understand the topic, they'll joke about Marijuana and what not.

    That is all.

    J.

  • As long as this isn't similar to previous claims of Cold Fusion in tupperware and the Emperor getting new 'clothes' then it may be something to get excited about.

  • Translated and edited Dutch news article (Score:5, Informative)

    by Anonymous Coward on Thursday March 01, 2012 @04:36PM (#39214451)

    I may or may not have butchered this, but I think its better than googles. All edits from original google translation are mine, as are any omissions.

    --

    Since 1937, physicists in Delft have sought to observe evidence of Majorana fermions, a fundamental particle whose properties may soon be used in quantum supercomputing.

    Recently, Delft physicists have claimed to be the first to create this exotic new elementary particle, showing in addition how it can play a key role in the supercomputer of the future. They made their discovery not in a giant particle accelerator, but at the intersection of superconducting nanowires on a chip.

    Prof. Leo Kouwenhoven, who made the discovery, announced the results at the annual meeting of the American Physical Society (APS). The news caused a wave of excitement among the thousands of present physicists. A reporter of the weekly Nature likened the situation to a busy train station during rush hour.

    "Have we seen Majorana fermions? I'd say a cautious 'yes'", stated Kouwenhoven at the end of his presentation in Boston. Other physicists said that the Delft measurements cannot be explained other than by the presence of a Majorana-like particle.

    The results have been published in the journal "Physical Review Letters". The so-called Majorana-fermion is one of the strangest elementary particles that physicists know, at least on paper. The possible existence was predicted in 1937 by the Italian physicist Ettore Majorana (1906-1938). Since then, physicists have looked everywhere for natural Majorana particles, but without success. Several years ago, attention was shifted to the observable effects in some solids which Majorana particles would create.

    The Delft group found the first indications of the Majorana particles at the ends of a partially superconducting microscopic thread of indium antimonide. Kouwenhoven has long been investigating such nanowires -- last year he received a grant of one million dollars of software maker Microsoft for his quest for the artificial-Majorana fermion. Even physics financier FOM put up one million.

    Microsoft's interest stems from the possibility of computer memory with Majorana particles. Such a computer would not use 1 or 0 bit states; Instead, it will use quantum bits, which facilitate much more computation. The problem with such a quantum computer is that quantum bits are sensitive to disturbances. Pairs of Majorana particles form an exception. They can be disrupted, but owing to their special mathematical properties, they always spring back to their original state. That is a desired property for a robust quantum memory system.

    In the research, each memory element comprises a nanowire of indium-arsenide in which two electrodes with the underlying quasi-particles produce so-called Majorana's. These are not sensitive to external disturbances causing an internal conditions change. The two Majorana on each of the elements form together a qubit. Qubits are the ones and zeros which allow a quantum computer to carry out numerous calculations simultaneously, instead of all the calculation steps one by one, as in conventional computers.

  • [a,a+]=1 (Score:4, Interesting)

    by Janek Kozicki ( 722688 ) on Thursday March 01, 2012 @05:27PM (#39215037) Journal

    OK, Majorana Fermion is a particle for which a=a+
    But by definition the second quantization operators [a,a+]=(aa+)-(a+a)=1

    So we have a contradiction here, because if a=a+, then [a,a+]=0, which does not obey to the definition of second quantization operator.

    Someone cares to enlighten me?

    How do those Majorana a and a+ operators look in positional representation? How does the first wave function look like?

    I'll try later to find original Majorana papers, but in meantime if you have some hints I'd be glad to hear.

    • Re: (Score:1)

      by Anonymous Coward

      They are fermions so {a,a+}=1 not [a,a+]=1 because fermions obey anti-commutation relations due to the spin commutation rule (spin 1/2 particles anti-commute while spin 1 and spin0 particles commute...

    • Re:[a,a+]=1 (Score:4, Insightful)

      by zakaryah ( 1344891 ) on Thursday March 01, 2012 @06:35PM (#39215643)
      For fermions, the canonical commutation relations must use the anticommutator: {a,b} = ab + ba. The Majorana fermion is a fermion. But, that doesn't completely answer your question, since you could correctly apply your reasoning to bosons which are their own antiparticle, like the photon, to claim that [a,a+]=0. But you have to keep in mind that the antiparticle of a photon is time-reversed compared to that photon - a+ and a are still distinct.

      • thanks, now it all started to make sense. But I'm still curious how does this operator exactly look like in position representation.

        • It depends on the Hamiltonian. But, you can calculate it in the following way for some systems you are familiar with: Let a+ and a be creation/annihilation operators for your (non-Majorana) fermion. You can define new operators, which obey the commutation relation for fermions: b = (a+ + a)/2 and b' = (a+ - a)/2i. But both of these operators satisfy bi = bi+, so the quasiparticles on which these operators act are Majorana fermions. If you want the position representation for b or b', you just need the p
  • For a moment I felt I was in one of those Star Trek TNG episodes where the plot advances thanks to an ad hoc particle/field that can be polarity-reversed. Usually the particle/field in question was seldom, or never mentioned later. Talk of science imitating art.

  • Oulde Neuws (Score:3)

    by Obfuscant ( 592200 ) on Thursday March 01, 2012 @07:30PM (#39216093)
    This is old news. When I was at Deltares a couple of years ago, they had three or four mating pairs of Majorana Fermions swimming in the pool near their main offices. I don't think they were spotted, though. They were speckled.

    That's pretty close to TU Delft, so maybe the ones TU Delft has found are one of the pairs from Deltares?

    At least I THINK that's what the Dutch speaking guide called them.

  • Can I get some excitment around me too?
    I haven't been laid in a while ...

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