Slashdot Mirror
Under the Hood of Quantum Computing
nanotrends writes "Gordie Rose, the CTO of Dwave Systems, the venture funded company that plans to offer paid use of a superconducting quantum computer starting in 2007, reveals secrets of his quantum computer construction. It is based on nobium superconducting 'circuits of atoms' and is not RSFQ. (Rapid Single Flux quantum)."
I read the article, but it didn't make it very clear - what will be the advantages of paid use of their quantum computer? Unless it's going to be faster than other supercomputers, I can't see the point. Is there some other advantage I'm not aware of?
I'd be very suprised if their quantum computer will be faster than conventional computers by next year. 20 years away, maybe.
"A week in the lab saves an hour in the library"
Wow, they use quantum mechanics? Every chemical reaction in our universe uses quantum mechanics; they couldn't be more vague if they tried. They're clearly trying to capitalize on the 'quantum computer' buzz.
// MD_Update(&m,buf,j);
... What have I missed here?
For starters; a link to the company's website instead of somebody's "See Spot run" blog post:
http://www.dwavesys.com/quantumcomputing.php
KFG
A functional quantum computer? Really?
I used to be a undergrad lab assistant. I never worked in quantum computing, but our neighbours were some of these guys. I picked up a few things, one of those things being that quantum computing is hard.
Classical computers use the laws of classical physics to operate. Classical physics is deterministic, and that's how we want our classical computers to behave. As the chip and die sizes get smaller and smaller (what are we at now, 65nm?) CPUs are more likely to suffer from quantum effects, but AFAIK there's circutry in there to compensate for that. Error checking.
A quantum computer is just a machine that uses the laws of quantum mechanics rather than the laws of classical mechanics to operate. The advantage is that some algorithms, when implemented on a quantum computer, are 2n instead of n^2. I never really understood this, maybe a better physicist will come along and explain it. Anyway, to build a quantum computer one needs two things:
- (a) You need some Quantum bits (qbits) to store data
- (b) You need to get those bits to interact with each other in some fashion
There are many approaches to building a quantum computer. One guy (Raymond Laflamme) has a bunch of different atoms that are different elements all in the same molecule, those interact with each other but he has only developed the ability to read / write to about 5 different qbits. I read about another guy on Slashdot here who made a giant array of qbits using atoms in a laser trap. That gets you a lot of qbits, but they don't interact at all. There are many approaches.
Anyway, the reason I think Dwave Systems is full of bullshit is that any approach thus far is good at (a) or (b), but not both. Someone who got a powerful quantum computer up and running would most assuredly win a Nobel Prize. Also, why the hell would he need to woo venture capital? I know I'm up in Canada, but I'm sure most governments are throwing scads and scads of research money at Quantum computing. Answer? Venture capitalists are more naive.
If there's anything I learned from here, it's that a lot of Con artists use buzzwords to try and justify their woo-woo science. "Quantum" is one of them.
Smart money on this guy being a fraud.
"Live as if you'll die tomorrow." Ridiculous. You could die later today.
What would be the point of funding something already useful? Things are funded on the basis of their potential, not on what they can do now.
From what has been described on the blog and website, i'm not convinced that what they're working on is much more than simply a superconducting RSFQ - Rapid Single Flux Quantum - chip, which although can concievably run at a breakneck speed compared to todays Silicon CPU's, is not a Quantum Computer in the normal sense. This thing isn't going to run Shor's Algorithm. Also, i'm surprised to notice that there are people here who still consider QCs as science fiction - they're not. Quantum Computing has been practical in the lab since the 90's - and, for example, composite numbers have been factorised in polynomial time. The challenge faced by QCT research groups around the world at present is mainly building the things with a large number of qubits, and still maintaining successful operation. With regards to solid state devices such as the Kane QC model, one of the approaches being investigated involves building multiple small QCs and interconnecting them via conventional microelectronics - perhaps SETs, RSFQs, spintronics or maybe even plain old silicon microelectronics - to create a useful, many-qubit, computer.
As a physicist who had courses in Quantum Computation I had to vomit when I just read the Title Superconducting Quantum Computer.
There are only two Quantum Algorithms with applications in real live AFAIK Shor's factoring Algorithm to find the Prime Factors of a number in polynomial time, and a boosted search algorithm, which gives a \sqrt(O) speed boost. The largest number Shor's Algorithm could be used on is 15. And it won't be usefull before we reach 16 bit's or so (which we won't in my lifetime with any of the approaches discussed today). The larges stable aray of qubits is 8 AFAIK, and you cannot do anything with those so far everybody is just working on stbility and prooves of concept.
1) Hence there is no usefull quantum computer in existence. Anyone who want's to sell you one is a liar.
Superconductivity, is well known and not very hard to achieve. I can make pretty much any material superconducting if you just give me a liquid Helium 3/4 demixer. So once I have a working quantum computer, I can add some lead, empty a bottle of Liquid Helium over it, and claim, that I have a super conducting Quantum computer. To be fair it's often inherent in the design of a Quantum computer that it needs to be very cold. But it doesn't always need to be so. But what remains is
2) Saying a quantum computer is superconducting doesn't add any infomation about the usefullness of such a device.
So what could this headline mean:
Someone allows you to use his NMR (Nuclear Magnetic Resonance) device if you give him money.
(NMR is standard in todays chemistry labs, and very simple useless quantum algorithms (see "Deutsch algorithm") have been implemented with it.)
Where is the beef? Can an article still be kicked out at this stage?
If you assess the capabilities of the system, it disappears!
Please, for the good of Humanity, vote Obama.
http://www.technologyreview.com/read_article.aspx? id=14591&ch=infotech
Computers have infiltrated nearly every field of business and science, and they keep getting faster. Nonetheless, researchers routinely encounter problems impossible for even the most powerful supercomputers to solve. The remedy could be quantum computers, which would use the fantastic properties of quantum mechanics to crack such problems in seconds rather than centuries. Since the 1980s, physicists in academic labs and at firms such as IBM, Hewlett-Packard, and NEC have pursued a variety of quantum computing approaches, but none seems likely to deliver a working machine in less than 10 years.
Company: D-Wave Systems
Headquarters: Vancouver, British Columbia
Amount invested: $22 million Canadian (about $17.5 million U.S.)
Lead investor: Draper Fisher Jurvetson
Key founders: Geordie Rose, Alexandre Zagoskin, Bob Wiens, Haig Farris
Technology: Quantum computers
Vancouver startup D-Wave Systems, however, aims to build a quantum computer within three years. It won't be a fully functional quantum computer of the sort long envisioned; but D-Wave is on track to produce a special-purpose, "noisy" piece of quantum hardware that could solve many of the physical-simulation problems that stump today's computers, says David Meyer, a mathematician working on quantum algorithms at the University of California, San Diego.
The difference between D-Wave's system and other quantum computer designs is the particular properties of quantum mechanics that they exploit. Other systems rely on a property called entanglement, which says that any two particles that have interacted in the past, even if now spatially separated, may still influence each other's states. But that interdependence is easily disrupted by the particles' interactions with their environment. In contrast, D-Wave's design takes advantage of the far more robust property of quantum physics known as quantum tunneling, which allows particles to "magically" hop from one location to another.
Incorporated in April 1999, D-Wave originated as a series of conversations among students and lecturers at the University of British Columbia. Over the years, it has amassed intellectual property and narrowed its focus, while attracting almost $18 million in funding, initially from angel investors and more recently from the Canadian and German governments, and from venture capital firms. The company plans to complete a prototype device by the end of 2006; a version capable of solving commercial problems could be ready by 2008, says president and CEO Geordie Rose.
The aggressiveness of D-Wave's timetable is made possible by the simplicity of its device's design: an analog chip made of low-temperature superconductors. The chip must be cooled to -269 C with liquid helium, but it doesn't require the delicate state-of-the-art lasers, vacuum pumps, and other exotic machinery that other quantum computers need.
The design is also amenable to the lithography techniques used to make standard computer chips, further simplifying fabrication. D-Wave patterns an array of loops of low-temperature superconductors such as aluminum and niobium onto a chip. When electricity flows through them, the loops act like tiny magnets. Two refrigerator magnets will naturally flip so that they stick together, minimizing the energy between them. The loops in D-Wave's chip behave similarly, "flipping" the direction of current flow from clockwise to counterclockwise to minimize the magnetic flux between them. Depending on t