2000/07/31 by Harry Buhrman, Christoph Durr, Mark Heiligman +4 · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1137/s0097539702402780
published as SIAM Journal on Computing, 34(6), 1324-1330, 2005 · 15 pages. Supersedes quant-ph/007016v1 and quant-ph/0006136
arxiv created 2000/09/01 · arxiv updated 2017/01/10
We present several applications of quantum amplitude amplification to finding claws and collisions in ordered or unordered functions. Our algorithms generalize those of Brassard, Hoyer, and Tapp, and imply an O(N3/4 log N) quantum upper bound for the element distinctness problem in the comparison complexity model (contrasting with Theta(N log N) classical complexity). We also prove a lower bound of Omega(N1/2) comparisons for this problem and derive bounds for a number of related problems.