Quantum walk search through potential barriers

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

An ideal quantum walk transitions from one vertex to another with perfect fidelity, but in physical systems, the particle may be hindered by potential energy barriers. Then the particle has some amplitude of tunneling through the barriers, and some amplitude of staying put. We investigate the algorithmic consequence of such barriers for the quantum walk formulation of Grover's algorithm. We prove that the failure amplitude must scale as for search to retain its quantum runtime; otherwise, it searches in classical O(N) time. Thus searching larger 'databases' requires increasingly reliable hop operations or error correction. This condition holds for both discrete- and continuous-time quantum walks.

Original languageEnglish (US)
Article number484002
JournalJournal of Physics A: Mathematical and Theoretical
Volume49
Issue number48
DOIs
StatePublished - Nov 9 2016
Externally publishedYes

Fingerprint

Quantum Walk
Energy barriers
Error correction
Potential energy
Error Correction
Fidelity
Continuous Time
apexes
potential energy
formulations
Formulation
Vertex of a graph
Energy

All Science Journal Classification (ASJC) codes

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Modeling and Simulation
  • Mathematical Physics
  • Physics and Astronomy(all)

Cite this

Quantum walk search through potential barriers. / Wong, Thomas.

In: Journal of Physics A: Mathematical and Theoretical, Vol. 49, No. 48, 484002, 09.11.2016.

Research output: Contribution to journalArticle

@article{0aabafc2e6634af799babe1cd18cec58,
title = "Quantum walk search through potential barriers",
abstract = "An ideal quantum walk transitions from one vertex to another with perfect fidelity, but in physical systems, the particle may be hindered by potential energy barriers. Then the particle has some amplitude of tunneling through the barriers, and some amplitude of staying put. We investigate the algorithmic consequence of such barriers for the quantum walk formulation of Grover's algorithm. We prove that the failure amplitude must scale as for search to retain its quantum runtime; otherwise, it searches in classical O(N) time. Thus searching larger 'databases' requires increasingly reliable hop operations or error correction. This condition holds for both discrete- and continuous-time quantum walks.",
author = "Thomas Wong",
year = "2016",
month = "11",
day = "9",
doi = "10.1088/1751-8113/49/48/484002",
language = "English (US)",
volume = "49",
journal = "Journal of Physics A: Mathematical and Theoretical",
issn = "1751-8113",
publisher = "IOP Publishing Ltd.",
number = "48",

}

TY - JOUR

T1 - Quantum walk search through potential barriers

AU - Wong, Thomas

PY - 2016/11/9

Y1 - 2016/11/9

N2 - An ideal quantum walk transitions from one vertex to another with perfect fidelity, but in physical systems, the particle may be hindered by potential energy barriers. Then the particle has some amplitude of tunneling through the barriers, and some amplitude of staying put. We investigate the algorithmic consequence of such barriers for the quantum walk formulation of Grover's algorithm. We prove that the failure amplitude must scale as for search to retain its quantum runtime; otherwise, it searches in classical O(N) time. Thus searching larger 'databases' requires increasingly reliable hop operations or error correction. This condition holds for both discrete- and continuous-time quantum walks.

AB - An ideal quantum walk transitions from one vertex to another with perfect fidelity, but in physical systems, the particle may be hindered by potential energy barriers. Then the particle has some amplitude of tunneling through the barriers, and some amplitude of staying put. We investigate the algorithmic consequence of such barriers for the quantum walk formulation of Grover's algorithm. We prove that the failure amplitude must scale as for search to retain its quantum runtime; otherwise, it searches in classical O(N) time. Thus searching larger 'databases' requires increasingly reliable hop operations or error correction. This condition holds for both discrete- and continuous-time quantum walks.

UR - http://www.scopus.com/inward/record.url?scp=84995414683&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84995414683&partnerID=8YFLogxK

U2 - 10.1088/1751-8113/49/48/484002

DO - 10.1088/1751-8113/49/48/484002

M3 - Article

AN - SCOPUS:84995414683

VL - 49

JO - Journal of Physics A: Mathematical and Theoretical

JF - Journal of Physics A: Mathematical and Theoretical

SN - 1751-8113

IS - 48

M1 - 484002

ER -