Stacey Jeffery - Quadratic speedup for quantum walk search

Speaker: Stacey Jeffery (CWI/QuSoft)
Title: Quadratic speedup for finding marked vertices by quantum walks

Date: Thursday, 14 March 2019
Event: Distinguished Lectures on Quantum Software
Website: http://quantumsc.nl/Events/Archive/ev...

Abstract: A quantum walk algorithm can detect the presence of a marked vertex on a graph quadratically faster than the corresponding random walk algorithm (Szegedy, FOCS 2004). However, quantum algorithms that actually find a marked element quadratically faster than a classical random walk were only known for the special case when the marked set consists of just a single vertex, or in the case of some specific graphs. We present a new quantum algorithm for finding a marked vertex in any graph, with any set of marked vertices, quadratically faster than the corresponding classical random walk.

This is joint work with Andris Ambainis, András Gilyén, and Martins Kokainis.