Correcting for potential barriers in quantum walk search

Andris Ambainis, Thomas Wong

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

A randomly walking quantum particle searches in Grover’s (formula presented) iterations for a marked vertex on the complete graph of N vertices by repeatedly querying an oracle that flips the amplitude at the marked vertex, scattering by a “coin” flip, and hopping. Physically, however, potential energy barriers can hinder the hop and cause the search to fail, even when the amplitude of not hopping decreases with N. We correct for these errors by interpreting the quantum walk search as an amplitude amplification algorithm and modifying the phases applied by the coin flip and oracle such that the amplification recovers the (formula presented) runtime.

Original languageEnglish (US)
Pages (from-to)1365-1372
Number of pages8
JournalQuantum Information and Computation
Volume15
Issue number15-16
StatePublished - Jan 1 2015
Externally publishedYes

Fingerprint

Quantum Walk
Flip
Amplification
apexes
Energy barriers
Potential energy
walking
Scattering
Vertex of a graph
Complete Graph
iteration
potential energy
Iteration
Decrease
causes
Energy
scattering

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • Statistical and Nonlinear Physics
  • Nuclear and High Energy Physics
  • Mathematical Physics
  • Physics and Astronomy(all)
  • Computational Theory and Mathematics

Cite this

Correcting for potential barriers in quantum walk search. / Ambainis, Andris; Wong, Thomas.

In: Quantum Information and Computation, Vol. 15, No. 15-16, 01.01.2015, p. 1365-1372.

Research output: Contribution to journalArticle

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