Is this the first practical quantum computer? (D-wave 128 qbit box) | Hacker News Reader

Is this the first practical quantum computer? (D-wave 128 qbit box)

dwavesys.com

43 pointsiwwr19 comments

It's not fake, but it's not the quantum computer you would expect.

http://spectrum.ieee.org/computing/hardware/loser-dwave-does...

"D-Wave's system uses a chip with little loops of niobium metal containing Josephson junctions—two superconductors separated by an insulator. When the chip is cooled to very low temperatures, tiny electrical currents flowing around the loops exhibit quantum properties, and you can use the direction to represent the states of a qubit: Counterclockwise represents 0, clockwise represents 1, and current flowing both ways represents a superposition of 0 and 1.

D-Wave's superconducting qubits are not new, and other groups use similar devices. But whereas most groups are trying to build the quantum logic gates from which all computing operations can be derived—an approach known as the gate model—D-Wave has adopted a different approach, called adiabatic quantum computation. Here's the gist: You initialize a collection of qubits to their lowest energy state. You then ever so gently (or adiabatically) turn on interactions between the qubits, thus encoding a quantum algorithm. In the end, the qubits drift to a new lowest-energy state. You then read out the qubits to get the results."

Yes, I wish they'd stop calling it a "quantum computer". It's not a quantum computer. It's a thingy.

That said, I'm quite impressed that D-Wave is finally bringing out a thingy that actually does something. Reading the Scott Aaronson post elsewhere in this thread it appears that they've finally got around to demonstrating that their thingy really does do stuff that involves quantum mechanics.

They're still way behind their implausible schedule, and their thingy still can't do anything that a classical computer can't do a helluva lot faster and cheaper, but I do congratulate them on having a proper working thingy.

But they need to stop calling this thingy a quantum computer.

Oh man, I was a solder monkey for the Orlando group at MIT in my sophomore year, and we also used niobium loops for QBits. That box has got to be pretty big, though. Niobium doesn't superconduct until you bring it down to less that 10K, and to get a stable qbit we had to bring things down into the 100mK range - requiring a helium dilution refrigerator.

http://en.wikipedia.org/wiki/Dilution_refrigerator

D-Wave has been operating under heavy-duty NDA's for a long time. I know of at least two published authors in quantum physics who have signed an NDA and been given the grand tour. I know one well enough to have asked him what he thought without divulging anything he couldn't tell me. He said what D-Wave had when he was there was not a general purpose quantum computer, but rather, a sort of hard-coded specific purpose device not unlike an electronic circuit built to implement a specific algorithm rather than function as a general purpose programmable device.

Regardless, what D-Wave has is real enough that they are not being laughed at in the circles that matter. I would also say that they aren't doing anything that makes academics who are working on QC devices despair of doing anything useful themselves. I think it's rather unlikely that this device is going to be busting open RSA keys anytime soon.

In short, this is probably not fake or a scam. It's just not quite what the original poster was hoping it was.

From what I've heard, this thing is designed to solve whatever can be transformed into energy minimization problems - "travelling salesman", routing the wires on printed circuit boards, urban planning, etc etc.

Scott Aaronson is an MIT prof and a leading researcher in quantum computing. Here is his take on a recent paper DWave published in Nature:

http://www.scottaaronson.com/blog/?p=639

(And the Nature paper: http://www.nature.com/nature/journal/v473/n7346/full/nature1...)

"after four years of the quantum computing community being told to review a restaurant based solely on its ice water and table settings, I’m delighted that D-Wave has finally brought an appetizer."

haha... those physicists

Later in that article:

> As some of you might be aware, I’m a theoretical computer scientist, not a physicist (much less an experimentalist).

ok so where is the "hello world" program for this type of system? .. wonders if it could figure out the HTML5 specs before we do?

Please consider returning to slashdot

Is... is this real?

I emailed them asking how much and when. $10million USD available now.

Ouch.

Maybe. But if you try to check, it may affect the scam result... i mean test results.

"Commercial"? That website looks like it's using the same web template as Orbo.

"It's a Ming Mecca chip!"

This is a) fake or b) a scam.

Yes, some quick googling appears to show that they've been pushing similar scams since 2007 or so:

http://www.google.com/search?sourceid=chrome&ie=UTF-8...

They claimed to have a 16-qubit machine then, whereas a recent (May 2) New Yorker article revealed that Oxford's research lab quantum computer is only an 8-qubit machine, and that's in 2011. Yale has built one and it's only 2-qubit.

or maybe neither. Dwave has been around for a while and while the question is still out on how useful their devices actually are they have been publicly demonstrated and available for at least a few years. Google has even used their machines though I think just for research purposes.

DWave just published a paper in Nature that shows that they have built a 8 qubit quantum device. This could be legit. However even if what they say is 100% true and correct, it's still not a 'general' quantum computer, it's only wired for one kind of optimization problem, and it's only 128 qubits which will not allow you to do things current computers can not yet do. You need closer to 1000 qubits for that.

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