Quantum algorithm for linear systems of equations.

  title={Quantum algorithm for linear systems of equations.},
  author={Aram Wettroth Harrow and Avinatan Hassidim and Seth Lloyd},
  journal={Physical review letters},
  volume={103 15},
Solving linear systems of equations is a common problem that arises both on its own and as a subroutine in more complex problems: given a matrix A and a vector b(-->), find a vector x(-->) such that Ax(-->) = b(-->). We consider the case where one does not need to know the solution x(-->) itself, but rather an approximation of the expectation value of some operator associated with x(-->), e.g., x(-->)(dagger) Mx(-->) for some matrix M. In this case, when A is sparse, N x N and has condition… 

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