Google might have wasted its cash on a quantum computer

Last year boffins were shocked when Google wrote a cheque for $15 million for a quantum computer system called DWave.

Now it turns out that the device may not be all it’s cracked up to be and it might not be a quantum computer after all and Google was not the only one to fall for it.

Aerospace giant Lockheed Martin paid a cool $10 million for the world’s first commercial quantum computer from a Canadian start up called D-Wave Systems. Last year, Google and NASA bought a second generation device for about $15 million with Lockheed upgrading its own machine for a further $10 million.

At the time, the move was heralded as a new era for quantum computation. Particularly when last year Cathy McGeoch at Amherst College in Massachusetts said she’d clocked the D-Wave device solving a certain class of problem some 3600 times faster than a conventional computer.

But now, according to,  D-Wave has undergone a dramatic change in fortune.

A report from a team of physicists from IBM’s T J Watson Research Laboratory in Yorktown Heights, NY, and the University of California Berkeley, say that D-Wave’s machine may not be quantum at all.

Umesh Vazirani, one of quantum computing’s early pioneers, pointed out that the method used to define the machine’s “quantumness” did not really work. In fact the tests used could easily be explained with another classical algorithm.

“We outline a simple new classical model, and show that on the same data it yields correlations with the D-Wave input-output behaviour that are at least as good as those of simulated quantum annealing,” he wrote.

In other words if the D-Wave computer was not quantum at all, it would still be capable of producing the same results.

D-Wave can still argue that its machine is quantum but in a way that is not revealed in these tests. But at some point it’ll need to produce evidence to back up this claim and this might be tricky.

What is probably embarrassing for Google, NASA and Lockheed Martin is that they could have shelled out tens of millions for a cryogenically cooled pocket calculator or a potentially dead or alive cat.