JeremyHsu writes: A one-second delay can still seem like an eternity for a quantum computing machine capable of running calculations in mere millionths of a second. That delay represents just one of the challenges D-Wave Systems overcame in building its second-generation quantum computing machine known as D-Wave Two — a system that has been leased to customers such as Google, NASA and Lockheed Martin. D-Wave's rapid-scaling approach to quantum computing has plenty of critics, but the company's experience in building large-scale quantum computing hardware could provide valuable lessons for everyone, regardless of whether the D-Wave machines live up to quantum computing's potential by proving they can outperform classical computers. (D-Wave recently detailed the hardware design changes between its first- and second-generation quantum computing machines in the the June 2014 issue of the journal IEEE Transactions on Applied Superconductivity.)
"We were nervous about going down this path," says Jeremy Hilton, vice president of processor development at D-Wave Systems. "This architecture requires the qubits and the quantum devices to be intermingled with all these big classical objects. The threat you worry about is noise and impact of all this stuff hanging around the qubits. Traditional experiments in quantum computing have qubits in almost perfect isolation. But if you want quantum computing to be scalable, it will have to be immersed in a sea of computing complexity.