The U.S. National Aeronautics and Space Administration confirmed Thursday that it built a special chip used in a disputed demonstration of quantum computing in February.
NASA engineers used their experience with submicrometer dimensions and ultra-low temperatures to build a quantum processor for Canadian startup D-Wave Systems, said Alan Kleinsasser, principal investigator in the quantum chip program at NASA's Jet Propulsion Laboratory in Pasadena, California.
D-Wave claimed to demonstrate a prototype quantum computer during a news conference Feb. 13 at the Computer History Museum in Mountain View, California. But industry experts became skeptical when D-Wave revealed it had left the computer at its Vancouver office, then conducted the demonstration over a Web link.
"You could characterize our announcement as being met with enthusiasm from industry and skepticism from academia," D-Wave CEO Ed Martin said in an interview Feb. 27. But he said the event served as proof of concept of the technology and that D-Wave's potential customers are businesses that don't care how the technology works as long as it can solve their complex models. He plans to start renting time on the machine to customers in 2008.
"Businesses aren't too fascinated about the details of quantum mechanics, but academics have their own axes to grind. I can assure you that our VCs look at us a lot closer than the government looks at the academics who win research grants," Martin said.
He described D-Wave's computer as a hybrid, running applications on a traditional, digital computer and using a single quantum processor as an accelerator or coprocessor. Martin said the back end is a rack-mounted PC with an off-the-shelf processor, but he wouldn't cite the specific brand.
The crucial part is the quantum chip, which is a processor built from the superconducting materials aluminum and niobium, then chilled in a tank of liquid helium. It achieves supercomputing speeds because its basic data units -- called qubits -- can hold both the values 0 and 1 simultaneously, and instantly share those values among all the qubits. A standard digital processor assigns a specific value to each data bit, and handles them one at a time.
D-Wave designed the quantum chip and then contracted with NASA to build it. The request was nothing new for engineers at the MDL (Microdevices Laboratory), a unit of NASA's Jet Propulsion Laboratory, who were accustomed to building superconducting circuits for clients like Hypres, a company in Elmsford, New York, and for instruments used aboard spacecraft like the European Space Agency's Herschel mission.
"There has been activity in MDL in quantum technology, including quantum computing, for around 10 years," Kleinsasser said. "Superconducting quantum computing technology requires devices and ultra-low [millikelvin] temperatures that are also required in much of our sensor work. A couple of years ago, D-Wave recognized that JPL is capable of producing the chips it wished to design. There is no [private] industry that can deliver such superconducting devices. So we worked out a collaboration that produced the chips that D-Wave is currently using."
The computer that D-Wave used for the Feb. 13 demonstration had a chip capable of running at 16 qubits, Martin said. The company plans to scale its machine much larger in the next 18 months, reaching 32 qubits by the end of 2007, then 512 qubits and 1,024 qubits by the end of 2008.
Still, D-Wave will surprise a lot of experts if it can reach its goals. Many analysts say quantum computing is feasible but that a working system is still a decade or more away.
"Given the kind of upheaval a working quantum system would bring, especially to the financial system where cryptography would become vulnerable, it would be major technology breakthrough," said Martin Kariithi, an analyst with Technology Business Research.
"I don't think a small company like D-Wave would pull it off; they are likely to get absorbed by a tech heavyweight like Intel or IBM as they get within five to eight years of a solution," he said.