Experimental detection of nonclassical correlations in mixed-state quantum computation

Journal Article · Sat Oct 15 00:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.044302· OSTI ID:22093412

Passante, G.; Moussa, O.; Trottier, D. A. ^[1]; Laflamme, R. ^[1]

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1. Institute for Quantum Computing and Department of Physics, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)

We report on an experiment to detect nonclassical correlations in a highly mixed state. The correlations are characterized by the quantum discord and are observed using four qubits in a liquid-state nuclear magnetic resonance quantum information processor. The state analyzed is the output of a DQC1 computation, whose input is a single quantum bit accompanied by n maximally mixed qubits. This model of computation outperforms the best known classical algorithms and, although it contains vanishing entanglement, it is known to have quantum correlations characterized by the quantum discord. This experiment detects nonvanishing quantum discord, ensuring the existence of nonclassical correlations as measured by the quantum discord.

• OSTI ID: 22093412
• Journal Information: Physical Review. A, Vol. 84, Issue 4; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALGORITHMS
CALCULATION METHODS
CORRELATIONS
MIXED STATE
NUCLEAR MAGNETIC RESONANCE
QUANTUM COMPUTERS
QUANTUM ENTANGLEMENT
QUANTUM MECHANICS
QUBITS