%0 Journal Article
%J Physical Review Letters
%D 2005
%T Fast quantum algorithm for numerical gradient estimation
%A Stephen P. Jordan
%X Given a blackbox for f, a smooth real scalar function of d real variables, one wants to estimate the gradient of f at a given point with n bits of precision. On a classical computer this requires a minimum of d+1 blackbox queries, whereas on a quantum computer it requires only one query regardless of d. The number of bits of precision to which f must be evaluated matches the classical requirement in the limit of large n.
%B Physical Review Letters
%V 95
%8 2005/7/28
%G eng
%U http://arxiv.org/abs/quant-ph/0405146v2
%N 5
%! Phys. Rev. Lett.
%R 10.1103/PhysRevLett.95.050501