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Title: Experimental implementation of a discrete-time quantum random walk on an NMR quantum-information processor

Journal Article · · Physical Review. A
DOI:https://doi.org/10.1103/PHYSREVA.72.0· OSTI ID:20786280
; ; ;  [1]
  1. Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)

We present an experimental implementation of the coined discrete-time quantum walk on a square using a three-qubit liquid-state nuclear-magnetic-resonance (NMR) quantum-information processor (QIP). Contrary to its classical counterpart, we observe complete interference after certain steps and a periodicity in the evolution. Complete state tomography has been performed for each of the eight steps, making a full period. The results have extremely high fidelity with the expected states and show clearly the effects of quantum interference in the walk. We also show and discuss the importance of choosing a molecule with a natural Hamiltonian well suited to a NMR QIP by implementing the same algorithm on a second molecule. Finally, we show experimentally that decoherence after each step makes the statistics of the quantum walk tend to that of the classical random walk.

OSTI ID:
20786280
Journal Information:
Physical Review. A, Vol. 72, Issue 6; Other Information: DOI: 10.1103/PhysRevA.72.062317; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
Country of Publication:
United States
Language:
English

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