Australian Researchers Devise Fault-Tolerant Quantum Computer

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."

The problem with this

[fyngyrz]

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.

Re:

[dbIII]

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 supermarke

Re:

[shentino]

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

Re:

[fyngyrz]

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

Re:

[dbIII]

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

Re:

[fyngyrz]

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 significa

Re:

[uninformedLuddite]

We live completely off the grid [blogspot.com]. Solar powered [blogspot.com] 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 [energymatters.com.au] 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 ge

Re:

[fyngyrz]

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 pr

Re:

[uninformedLuddite]

I should have included a caveat about living in a solar friendly environment [energymatters.com.au]. 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 attack

Re:

[socceroos]

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

Re:

[Phopojijo]

This post proves it. :-p

Re:

[pinkushun]

we won't know until we observe it =)

Re:

[pitchpipe]

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

Re:In other news

[pitchpipe]

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

Re:

[circletimessquare]

What's in the picnic basket?

-Yogi Bear

Re:

[MichaelSmith]

There is a difference between tolerating faults and ignoring them.

Fault tolerant?

[girlintraining]

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

Re:

[davester666]

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

Re:

[K. S. Kyosuke]

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?

Re:

[arth1]

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.

Re:

[dragin33]

lol

Let the bad jokes roll in

[Bozzio]

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

Re:

[MichaelSmith]

I predict at least 50 more.

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

Re:

[by (1706743)]

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...

Re:

[furgle]

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?..

Re:

[rts008]

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

Cure warts [cmu.edu] with them, of course!

Re:

[Sulphur]

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

Duplicats?

And the winner is...

[da3dAlus]

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

"Quantum repeaters", eh?

[John Hasler]

How about "quantum MITMs"?

Re:

[javalizard]

I'll eat quantum M&Ms!

Is this news?

[kasperd]

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.

Re:

[Anonymous Coward]

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.

Re:

[kasperd]

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

Re:

[MichaelKristopeit167]

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...

Re:

[kasperd]

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 c

Re:

[MichaelKristopeit189]

enormous - enormous = 0

enormous - (enormous * 2) = negatively enormous

you do not understand logic.

you're an idiot.

Re:

[account_deleted]

Comment removed based on user account deletion

*ahem*

[Qubit]

And what am I, chopped liver?

Re:

[Adambomb]

Noooahhhhh. Nooaahhh...

This is the Lord, Noahhhhh.

riiiiiiiiiiiight.

Link to paper on the arxiv

[kmac06]

Arxiv link [arxiv.org]

What this really means

[Lost Penguin]

"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?

So that means....

[tonejava]

My iPod will sync before I plug it in?

Re:

[ArsonSmith]

No that's called bluetooth.

Re:

[kevinmenzel]

No, but your blackberry already will...

So is this

[Mick R]

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

Re:

[yahwotqa]

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

Re:

[VoidCrow]

G.day!