6533b81ffe1ef96bd1277c62

RESEARCH PRODUCT

Faster Quantum Walk Search on a Weighted Graph

Thomas G. Wong

subject

PhysicsVertex (graph theory)Quantum particleQuantum PhysicsDegenerate energy levelsFOS: Physical sciencesGraph theory01 natural sciencesAtomic and Molecular Physics and OpticsGraph010305 fluids & plasmasCombinatoricsQuantum mechanics0103 physical sciencesQuantum walk010306 general physicsQuantum Physics (quant-ph)

description

A randomly walking quantum particle evolving by Schr\"odinger's equation searches for a unique marked vertex on the "simplex of complete graphs" in time $\Theta(N^{3/4})$. In this paper, we give a weighted version of this graph that preserves vertex-transitivity, and we show that the time to search on it can be reduced to nearly $\Theta(\sqrt{N})$. To prove this, we introduce two novel extensions to degenerate perturbation theory: an adjustment that distinguishes the weights of the edges, and a method to determine how precisely the jumping rate of the quantum walk must be chosen.

10.1103/physreva.92.032320http://arxiv.org/abs/1507.07590