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A Quantum Linear Equation Solver

Posted by kdawson on from the traveling-salesman-gets-a-break dept.

joe writes "Aram Harrow and colleagues have just published on the arXiv a quantum algorithm for solving systems of linear equations (paper, PDF). Until now, the only quantum algorithms of practical consequence have been Shor's algorithm for prime factoring, and Feynman-inspired quantum simulation algorithms. All other algorithms either solve problems with no known practical applications, or produce only a polynomial speedup versus classical algorithms. Harrow et. al.'s algorithm provides an exponential speedup over the best-known classical algorithms. Since solving linear equations is such a common task in computational science and engineering, this algorithm makes many more important problems that currently use thousands of hours of CPU time on supercomputers amenable to significant quantum speedup. Now we just need a large-scale quantum computer. Hurry up, guys!"

3 of 171 comments (clear)

  1. Re:Seems bogus by Anonymous Coward · · Score: 4, Insightful

    Maybe you should READ the damn thing and notice how that's addressed in the first half-page.

  2. Re:not able to be used == not useful by Andr+T. · · Score: 4, Insightful
    Maybe it's just a story, but I've read something about Faraday that made me think about what you've written.

    When the Prime Minister asked him about a new discovery, "What good is it?", Faraday replied, "What good is a newborn baby?"

    --

    Any life is made up of a single moment, the moment in which a man finds out, once and for all, who he is.

  3. Re:not able to be used == not useful by norton_I · · Score: 4, Insightful

    You think that quantum computers are not able to justify grants or PhDs? What world are you living in?

    until these quantum computers exist and are cheap enough to fill datacentres

    Yeah, because classical computers were never useful to anyone (or anyone important) until datacenters existed.

    No, to be really useful, quantum computing has to be as easy to afford and deploy as current computing technology.

    And until then, developments that bring us closer are irrelevant? Applications that could give us more reason to develop the technology are pointless?

    What exactly is your point here?