Today The Economist put out this paragon of hard-hitting D-Wave journalism. At first I merely got angry — but then I asked myself what Winston Churchill, Carl Sagan, or Chip ‘n Dale’s Rescue Rangers would do. So let’s see if The Economist prints the following.
In a remarkably uncritical article about D-Wave’s announcement of the “world’s first practical quantum computer” (Feb. 15), you gush that “[i]n principle, by putting a set of entangled qubits into a suitably tuned magnetic field, the optimal solution to a given NP-complete problem can be found in one shot.” This is simply incorrect. Today it is accepted that quantum computers could not solve NP-complete problems in a reasonable amount of time. Indeed, the view of quantum computers as able to “try all possible solutions in parallel,” and then instantly choose the correct one, is fundamentally mistaken. Since measurement outcomes in quantum mechanics are random, one can only achieve a computational speedup by carefully exploiting the phenomenon known as quantum interference. And while it is known how to use interference to achieve dramatic speedups for a few problems — such as factorising large integers, and thereby breaking certain cryptographic codes — those problems are much more specialised than the NP-complete problems.
Over the past few days, many news outlets have shown a depressing willingness to reprint D-Wave’s marketing hype, without even attempting to learn why most quantum computing researchers are sceptical. I expected better from The Economist.
Institute for Quantum Computing
University of Waterloo
I thought ‘factorising,’ ‘specialised,’ and ‘sceptical’ were a nice touch.
A Final Thought (2/16): As depressing as it is to see a lazy magazine writer, with a single harebrained sentence, cancel out your entire life’s work twenty times over, some good may yet come from this travesty. Where before I was reticent in the war against ignorant misunderstandings of quantum computing, now I have been radicalized — much as 9/11 radicalized Richard Dawkins in his war against religion. We, the quantum complexity theorists, are far from helpless in this fight. We, too, can launch a public relations campaign. We can speak truth to parallelism. So doofuses of the world: next time you excrete the words “NP-complete,” “solve,” and “instantaneous” anywhere near one another, brace yourselves for a Bennett-Bernstein-Brassard-Blitzirani the likes of which the multiverse has never seen.
Update (2/16): If you read the comments, Geordie Rose responds to me, and I respond to his response. Also see the comments on my earlier D-Wave post for more entertaining and ongoing debate.