TY - JOUR

T1 - How to detect a possible correlation from the information of a subsystem in quantum-mechanical systems

AU - Kimura, Gen

AU - Ohno, Hiromichi

AU - Hayashi, Hiroyuki

N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.

PY - 2007/10/23

Y1 - 2007/10/23

N2 - The possibility of detecting correlations between two quantum-mechanical systems from only the information of a subsystem is investigated. For generic cases, we prove that there exist correlations between two quantum systems if the time derivative of the reduced purity is not zero. Therefore, an experimentalist can conclude that correlations between the system and some environment are nonzero if the time derivative of the reduced purity is found not to be zero. A quantitative estimation of the time derivative of the reduced purity with respect to correlations is also given. This clarifies the role of correlations in the mechanism of decoherence in open quantum systems.

AB - The possibility of detecting correlations between two quantum-mechanical systems from only the information of a subsystem is investigated. For generic cases, we prove that there exist correlations between two quantum systems if the time derivative of the reduced purity is not zero. Therefore, an experimentalist can conclude that correlations between the system and some environment are nonzero if the time derivative of the reduced purity is found not to be zero. A quantitative estimation of the time derivative of the reduced purity with respect to correlations is also given. This clarifies the role of correlations in the mechanism of decoherence in open quantum systems.

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U2 - 10.1103/PhysRevA.76.042123

DO - 10.1103/PhysRevA.76.042123

M3 - Article

AN - SCOPUS:35549005000

SN - 1050-2947

VL - 76

JO - Physical Review A - Atomic, Molecular, and Optical Physics

JF - Physical Review A - Atomic, Molecular, and Optical Physics

IS - 4

M1 - 042123

ER -