paper

Quantum algorithm for systems of linear equations with exponentially improved dependence on precision

arXiv:1511.02306 · doi:10.1137/16M1087072

Abstract

Harrow, Hassidim, and Lloyd showed that for a suitably specified matrix and -dimensional vector , there is a quantum algorithm that outputs a quantum state proportional to the solution of the linear system of equations . If is sparse and well-conditioned, their algorithm runs in time , where is the desired precision in the output state. We improve this to an algorithm whose running time is polynomial in , exponentially improving the dependence on precision while keeping essentially the same dependence on other parameters. Our algorithm is based on a general technique for implementing any operator with a suitable Fourier or Chebyshev series representation. This allows us to bypass the quantum phase estimation algorithm, whose dependence on is prohibitive.

v1: 28 pages; v2: 31 pages, minor change to title, various minor changes and clarifications in response to referee comments

References in corpus (6)

Cited by in corpus (309)