Entangled graphs. II. Classical correlations in multiqubit entangled systems

Journal Article · Tue Jul 01 04:00:00 EDT 2003 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.68.012313· OSTI ID:20639879

Plesch, Martin ^[1]; Buzek, Vladimir ^[1]

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1. Research Center for Quantum Information, Slovak Academy of Sciences, 845 11 Bratislava, (Slovakia)

Bipartite correlations in multiqubit systems cannot be shared freely. The presence of entanglement or classical correlation on certain pairs of qubits may imply correlations on other pairs. We present a method of characterization of bipartite correlations in multiqubit systems using a concept of entangled graphs which has been introduced in our earlier work [M. Plesch and V. Buzek, Phys. Rev. A 67, 012322 (2003)]. In entangled graphs, each qubit is represented by a vertex while the entanglement and classical correlations are represented by two types of edges. We prove by construction that any entangled graph with classical correlations can be represented by a mixed state of N qubits. However, not all entangled graphs with classical correlations can be represented by a pure state.

• OSTI ID: 20639879
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 68; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CORRELATIONS
ENERGY LEVELS
GRAPH THEORY
INFORMATION THEORY
MIXED STATE
QUANTUM MECHANICS