A new algorithm may give quantum computers a new, practical job: quickly solving monster linear equations. Such problems are at the heart of complex processes such as image and video processing, genetic analyses and even Internet traffic control. The new work, published October 7 in Physical Review Letters, may dramatically expand the range of potential uses for quantum computers.
The new quantum algorithm is “head-smackingly good,” says computer scientist Daniel Spielman of Yale University. “It is both very powerful, and very natural. I read the abstract and said, ‘Why didn’t I think of that?’”
In the new study, Aram Harrow of the University of Bristol in England along with Avinatan Hassidim and Seth Lloyd, both of MIT, propose that large datasets of linear equations could be encoded in quantum forms, such as the spins of nuclei, individual atoms or photons. Such a system would allow quantum computers to handily solve problems made up of billions or even trillions of variables (such as the x’s, y’s and z’s that plague algebra students).
“Solving these gigantic equations is a really huge problem,” Lloyd says. “Even though there are good algorithms for doing it, it still takes a very long time.”