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Australian Researchers Devise Fault-Tolerant Quantum Computer

Posted by timothy on from the majority-rules dept.

schliz writes "Researchers have devised a theoretical quantum computer that could function even if one in four qubits were missing. The design is claimed to be the first that tolerates both qubit loss and decoherance to this extent. It performs calculations by measuring, rather than manipulating qubits, so there are fewer points of failure."

63 comments

  1. The problem with this by Anonymous Coward · · Score: 0

    is that with a quantum computer you're never sure you got the right answer. With my current computer, I can be.

    1. Re:The problem with this by bazald · · Score: 0, Troll

      You are wrong. In both cases you have only probabilistic guarantees of correctness.

      --
      Insert self-referential sig here.
    2. Re:The problem with this by GNUALMAFUERTE · · Score: 0, Flamebait

      Except if you run windows. In that case, you can be 100% sure that the results are incorrect ;)

      --
      WTF am I doing replying to an AC at 5 A.M on a Friday night?
    3. Re:The problem with this by socceroos · · Score: 2, Interesting

      Surely it can be both correct and incorrect at the same time? =)

    4. Re:The problem with this by Phopojijo · · Score: 1

      This post proves it. :-p

    5. Re:The problem with this by dbIII · · Score: 1

      There's only something wrong with the widespread perception that things do not exist unless they are in the mass market. Some things end up in satellites or esoteric expensive bits of electronics and never end up at Walmart, normal journalists never hear of it and science journalists already reported the initial work a decade ago so see it as a finished story. You very rarely get bits of journalism like the radio interview of the inventor of the laser while he's having his shopping scanned at a supermarket (done a few years ago on Australia's ABC Science Show).
      Then of course there are the early announcements blown up in hype by University P.R. people that need to make a lot of noise to ensure the money keeps rolling in. That's where you get announcements as utterly stupid as the single layer micrometre thick bullet proof spandex costume from an idiot employed by MIT that should have run the article past his material scientists before he put it out (the reality was a lot of thin layers with as little contact between them as possible to make it difficult as possible for a shock wave to make it through the material - a bulky as normal but lighter weight bullet proof material).

    6. Re:The problem with this by pinkushun · · Score: 1

      we won't know until we observe it =)

    7. Re:The problem with this by shentino · · Score: 1

      Invention is a scientific process.
      Innovation is an economic process.

    8. Re:The problem with this by fyngyrz · · Score: 1

      I was referring more to the continual river of hope about finished items - quantum computers, low cost solar cells (that one is particularly troublesome), like that. Still waiting for a decent household robot, still waiting for memristors, still waiting for a real flying car, still waiting for "portable nuclear reactors", also fusion reactors, still waiting for a decent OLED monitor, still waiting for a consumer 3D printer, still waiting for cures for... well, a whole lotta stuff, really.

      These things are hard. The articles, though, seem more and more breathless to me, less attached to reality and more about just painting a picture they can be cheery about.

      For instance, I'm glad they've got fault-tolerance at the qbit level worked out in at least one way. Wahoo. Now, the important question to me is, when will they have a quantum computer? 10 years? 25? 100? When will it become relevant to my life? Sure, I know scientific work is ongoing, and that it is fundamental, but a whole lot of it is dead end, too.

      And on a vaguely related note, I wish like heck they'd get the space elevator thing worked out. Now there is something that would be a paradigm-shifter. Imagine, finally, real access to space. We could build a *real* space station, something that would support excursions into the rest of the solar system, not to mention science, medicine, huge amounts of solar power... yeah, that'd be number one on my list, all right. Sigh.

      --
      I've fallen off your lawn, and I can't get up.
    9. Re:The problem with this by dbIII · · Score: 1

      low cost solar cells

      A $5 thing with solar cells, capacitors and an LED that lights up the garden at night isn't good enough for you? We already have cheap solar cells and there's other non-silicon options that both look impressive and can get more than the optical range that are likely to bring it down even more. The really expensive high efficiency stuff is getting used with mirrors to cover more area and bring down the dollars per watt. What won't happen is photovoltaics pushing ahead of thermal power at very large scales - double the area and you only get double the power but with thermal doubling the size eventually gives better returns than that.
      You could probably make a 3d printer yourself with lego mindstorms, a computer, a laser with a bit of power and a tub of polyester (I think) resin. I saw one more than ten years ago driven by a machine with a pentium 100 or similar, and it was good enough to construct models of a childs deformed skull to plan for reconstructive surgury. I don't know if you could get many people to buy it since it's a fairly specialised thing and slow.
      I'm waiting for OLED too, or for the easily adjustable and cheap variable brightness window coating someone I know was working on a decade ago (humidity gave it trouble), or scramjets like the one I saw in 1987 - but it takes time to get all the bugs out sometime.
      As for medicine, there's a lot of progress but still a long way to go because we have a lot to learn about how the body works.

    10. Re:The problem with this by fyngyrz · · Score: 1

      A $5 thing with solar cells, capacitors and an LED that lights up the garden at night isn't good enough for you?

      Not even close. I want a system I can put on my roof and then cease relying on, and paying for, constant supply of hugely expensive power from the grid. The energy is there and it is wasted. Knowing that is frustrating. But PV systems are VERY expensive and the ROI is very slow because they're not very efficient, either... not to mention that the batteries have short lives and are a significant part of the cost; and that the PV cells themselves also tend to degrade over time. The point is to save money so I can do other things with it. As long as it's so expensive, it's not practical. I've got 30x50+10x20 worth of roof. You know how much solar energy hits that? It's astonishing. And I can't use it. Frustrating!

      You could probably make a 3d printer yourself with lego mindstorms, a computer, a laser with a bit of power and a tub of polyester (I think) resin.

      Nah, I don't want one that makes resin models, I want one that makes goods like radios, televisions, solar cells, computers, lunch... you get the idea. We're not even close.

      As for medicine, there's a lot of progress but still a long way to go because we have a lot to learn about how the body works.

      You said it. It's still very much an art. Maybe in a century or two, but I'll be long dead. Oh well. :)

      --
      I've fallen off your lawn, and I can't get up.
    11. Re:The problem with this by uninformedLuddite · · Score: 1

      We live completely off the grid. Solar powered with diesel backup and gel battery storage. The system has been running for eight years and the generator has run a total of 900 hours over that time (mostly just monthly/weekly battery maintenance cycles). We have an array of 24 2V 600mah Sonnenschein batteries and not one of them has shown any measurable variation in performance over eight years. We are still some time from break even(BE) on initial investment but as I watch supplied energy costs rising BE gets closer daily. Although, if we take into account the initial government subsidy received on purchase BE on our personal outlay is only a few years away.
      IMHO people holding off due to cost of initial investment, BE being a long wait, etcetera are doing themselves a disservice. Once BE becomes the major dot point of the sales pitch then the queues will be long, unobtainium rarer and more expensive, no more government subsidies, and increased sales taxes on alternate energy systems will be required to help bail out those poor bottom line affected and suffering power companies.

      --
      The new right fascists are bilingual. They speak English and Bullshit.
    12. Re:The problem with this by fyngyrz · · Score: 1

      Your system is very nice. I need about 10kw here that is operable from -40 to rooftop temps on 115f days (I don't know exactly what that is, except I know it's horrible), can withstand 90 mph winds or better and baseball sized hail -- (NE Montana has some pretty rough weather.) And it has to go on the roof without ripping it off in high winds - the available land here is in shadow. It's kind of a tough situation, and there are lots of extra costs because of the environmental considerations, but the main problem is the cost of PV... it's just too much right up front. Every time I see an article about "low cost PV" I grit my teeth. I can build the inverter myself - I'm an EE - and that would both save a lot of money and give me something I can 100% maintain myself - but the PV might as well be magic for all I can do about it.

      --
      I've fallen off your lawn, and I can't get up.
    13. Re:The problem with this by uninformedLuddite · · Score: 1

      I should have included a caveat about living in a solar friendly environment. 115F is 46C - it get's that hot here and believe me it sucks. We will get weeks of over 40C in summer. Although this year the weather has been completely fscked up/strange. I suspect that baseball sized hail would badly damage/destroy our panels. I have been toying with the idea of putting some old garage roll-a-doors in place so that the panels could be covered in an extreme event.
      Don't take this the wrong way as I am not attacking your engineering skills but(OMG here's the but) to home build an inverter like ours would be quite a feat and if you could pull it off you are a talented person. Here is a link to the inverter manual if you are interested in seeing what the unit itself does/manages.

      --
      The new right fascists are bilingual. They speak English and Bullshit.
  2. fault-tolerant? by Anonymous Coward · · Score: 0

    So, they're saying it can run Windows?

    1. Re:fault-tolerant? by MichaelSmith · · Score: 2, Funny

      There is a difference between tolerating faults and ignoring them.

      --
      http://michaelsmith.id.au
  3. Uses a RAID array of cats by Anonymous Coward · · Score: 0

    The cats have to be replaced or not replaced as needed.

    I think PETA will have problems with it, but the NSA doesn't care.

  4. Fault tolerant? by girlintraining · · Score: 4, Funny

    Oh sure, it's fault tolerant... until you look at it.

    --
    #fuckbeta #iamslashdot #dicemustdie
    1. Re:Fault tolerant? by davester666 · · Score: 1

      Yes, you can either precisely know the inputs, or precisely know the outputs, but never both...

      --
      Sleep your way to a whiter smile...date a dentist!
    2. Re:Fault tolerant? by K.+S.+Kyosuke · · Score: 1

      My machines frequently burn out whenever I go to the toilet (by now, one notebook MB and two desktop PSUs). Does that mean that I have antiquantum computers?

      --
      Ezekiel 23:20
    3. Re:Fault tolerant? by arth1 · · Score: 1

      Yeah, I don't get the part where it's supposed to be more resilient because you measure instead of manipulate bits. In quantum mechanics, the two are the same, i.e. you don't "stress" the matter any less by observing than by manipulating.

    4. Re:Fault tolerant? by dragin33 · · Score: 1

      lol

  5. Re:In other news by pitchpipe · · Score: 2, Insightful

    Researchers have devised a theoretical quantum computer that could function even if one in four qubits were missing.

    I think that this quote is apropos: In theory there is no difference between theory and practice. In practice there is. Yogi Berra

    --
    Look where all this talking got us, baby.
  6. Let the bad jokes roll in by Bozzio · · Score: 1

    3 bad Uncertainty Principle jokes already. I predict at least 50 more. Dupes count (obviously).

    --
    I just pooped your party.
    1. Re:Let the bad jokes roll in by MichaelSmith · · Score: 1

      I predict at least 50 more.

      So you plan to change the number of bad jokes by reading the thread?

      --
      http://michaelsmith.id.au
    2. Re:Let the bad jokes roll in by by+(1706743) · · Score: 1

      Q: Why didn't the good jokes about the uncertainty principle make it to the thread?
      A: They never left home -- "good jokes" and "uncertainty principle" don't commute.

      Secretly thinks the pun is kinda funny, but expects -1 Offtopics instead...

    3. Re:Let the bad jokes roll in by furgle · · Score: 1

      The problem with uncertainty principle jokes: the funnier the joke the more uncertain you are of the actual composition, and if you do end up finding the composition of the joke you can't tell how funny it is. Furthermore, what the hell do you do with a dead cat?..

    4. Re:Let the bad jokes roll in by Sulphur · · Score: 1

      3 bad Uncertainty Principle jokes already. I predict at least 50 more. Dupes count (obviously).

      Duplicats?

    5. Re:Let the bad jokes roll in by rts008 · · Score: 1

      Furthermore, what the hell do you do with a dead cat?

      Cure warts with them, of course!

      --
      Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
  7. And the winner is... by da3dAlus · · Score: 1

    Announcer: "...Number 3, in a quantum finish!"
    Farnsworth: "No fair! You changed the outcome by measuring it!"

    --

    Sometimes I doubt your commitment to Sparkle Motion.
  8. "Quantum repeaters", eh? by John+Hasler · · Score: 1

    How about "quantum MITMs"?

    --
    Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
    1. Re:"Quantum repeaters", eh? by javalizard · · Score: 1

      I'll eat quantum M&Ms!

  9. Is this news? by kasperd · · Score: 3, Interesting

    I recall hearing a talk about how to do fault tolerant quantum computing already six years ago. The main points I remember from the talk was that there was a theoretical limit to how much redundancy you could introduce as if you could reconstruct from half the qubits then you could clone the state, which is known to be impossible. I don't remember how large the gap was between the upper and lower bounds were, but they proved that at a certain error rate their redundant construction would improve the error rate, and could be applied multiple times to get even better error rates.

    --

    Do you care about the security of your wireless mouse?
    1. Re:Is this news? by Anonymous Coward · · Score: 1, Informative

      You're right that fault-tolerant quantum computers aren't new. The title of TFA is "Scientists raise quantum error threshold" which describes the achievement better than the Slashdot title.

    2. Re:Is this news? by MichaelKristopeit167 · · Score: 1

      more importantly, what is the overhead for the fault tolerance? does it affect real time latency? a quantum computer emulated in x86 hardware isn't very useful...

    3. Re:Is this news? by kasperd · · Score: 2, Interesting

      what is the overhead for the fault tolerance?

      Most likely that depends on the error rate of the physical hardware. The more errors the fault tolerance has to deal with, the more overhead there will be.

      does it affect real time latency?

      Latency is not really what is important to quantum computers. The typical use case for quantum computers is long running computations. The more interesting question is by how large a factor does the number of qubits increase, and does the possible number of qubits in a quantum computer increase fast enough with little increase in error rate to make such techniques useful? The next question will be by which factor the computation will be slowed down. But if the technique is feasible then the slowdown probably doesn't matter as the quantum computer will be much faster than all the alternatives anyway.

      --

      Do you care about the security of your wireless mouse?
    4. Re:Is this news? by kasperd · · Score: 1

      Unfortunately when I follow the link it just ends up in a redirection loop.

      --

      Do you care about the security of your wireless mouse?
    5. Re:Is this news? by Anonymous Coward · · Score: 0

      The overhead still makes it a quantum computer, that's just the rule of the game. What the hell is "real time latency" for a quantum computer? If by that you mean a slowdown by a constant factor then that's almost irrelevant since the quantum speedups are enormous.

    6. Re:Is this news? by Anonymous Coward · · Score: 0

      This if happening because you turned off cookies. If you're going to cripple some part of the HTTP standard on your end, you better remember that you did so when an HTTP request fails! May I suggest the option "Accept cookies, keep until I close my browser" which makes things work with reasonable privacy.

    7. Re:Is this news? by MichaelKristopeit189 · · Score: 1
      enormous - enormous = 0

      enormous - (enormous * 2) = negatively enormous

      you do not understand logic.

      you're an idiot.

  10. Re:Fuck Slashdot again by Anonymous Coward · · Score: 0

    I disagree.

    Sure, on the loose, the Slashdot mods are starting on the at time an animal. I'm fuckin' animal. The Slashdot mods didn't let me animal, But I'm fucking. Now it's in pain, it's in pain, it's involved, great, I'm fucking fifty steers. I'm involved, animal. Animal, getting fifty steers.

    I'm fuckin' animal. Drinkin' and now, loose, I'm fucking queers. I'm fucking on, her on an animal. I'll goose. I'm great. I'm fuckin' and now I'm fucking my dick you won't had.

  11. Re:In other news by Anonymous Coward · · Score: 0

    That quotation has been ascribed to several famous people. It's likely not from Yogi Berra. Kindly don't perpetuate urban legends. Thanks.

  12. Comment removed by account_deleted · · Score: 1

    Comment removed based on user account deletion

  13. Link to paper on the arxiv by kmac06 · · Score: 2, Informative

    Arxiv link

  14. Re:In other news by pitchpipe · · Score: 4, Funny

    That quotation has been ascribed to several famous people. It's likely not from Yogi Berra. Kindly don't perpetuate urban legends. Thanks. - Yogi Berri

    --
    Look where all this talking got us, baby.
  15. The problem with this by fyngyrz · · Score: 3, Interesting

    The problem here is the one fault it's not tolerant of is that it isn't even close to being a practical quantum computer, and so lands squarely in that magic world with all the high efficiency solar cells, nanotube based ultracaps, and the myriad of medical discoveries, of which only a very, very few actually make it to market -- the rest are dead ends, for whatever reason. I am actually beginning to find these announcements a little depressing. Either there's something really wrong with our "get it to market" system, or there's an awful lot of bullcrap out there. Neither answer is good.

    --
    I've fallen off your lawn, and I can't get up.
  16. *ahem* by Qubit · · Score: 1

    And what am I, chopped liver?

    --

    coding is life /* the rest is */
  17. What this really means by Lost+Penguin · · Score: 1

    "The design is claimed to be the first that tolerates both qubit loss and decoherance to this extent."

    Can we check on the cat now?

    --
    I am the unwilling control for my Origin.
  18. Re:In other news by circletimessquare · · Score: 1

    What's in the picnic basket?

    -Yogi Bear

    --
    intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
  19. So that means.... by tonejava · · Score: 1

    My iPod will sync before I plug it in?

    1. Re:So that means.... by ArsonSmith · · Score: 1

      No that's called bluetooth.

      --
      Paying taxes to buy civilization is like paying a hooker to buy love.
    2. Re:So that means.... by kevinmenzel · · Score: 1

      No, but your blackberry already will...

  20. So is this by Mick+R · · Score: 1

    a new implementation of the "she'll be right, mate!" algorithm, or the "no wucken furries!" paradigm?

    1. Re:So is this by Anonymous Coward · · Score: 0

      thats not a qubit, this is a qubit possibly? http://www.youtube.com/watch?v=01NHcTM5IA4

  21. Re:That's not a qubit ... by Adambomb · · Score: 1

    Noooahhhhh. Nooaahhh...

    This is the Lord, Noahhhhh.

    riiiiiiiiiiiight.

    --
    Ice Cream has no bones.
  22. Why Aussie and not Science? by Anonymous Coward · · Score: 0

    If this were about American scientists,
    Einstein's face would show up beneath the summary.
    But as it is about Australian scientists,
    the Aussie hat shows up.
    Why can't Aussie scientists be just taken seriously
    as normal scientists? After all, it's long since
    Australia was a colony of prisoners.

    And no, I'm not an Australian.

    1. Re:Why Aussie and not Science? by VoidCrow · · Score: 1

      G.day!

  23. Re:Nerds will never see a vagina by yahwotqa · · Score: 1

    So it's true - Microsoft fucks you over with Windows OS.

  24. ahh but by Anonymous Coward · · Score: 0

    can we use a number of fully commuting operators, to measure different states of a system, then the uncertainty principle wouldnt apply as the inequality relates to the anticommutator.