Witnessing quantum discord in 2xN systems

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.062102· OSTI ID:21407890

Bylicka, Bogna; Chruscinski, Dariusz ^[1]

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1. Institute of Physics, Nicolaus Copernicus University, GrudziaPdzka 5/7, PL-87-100 Torun (Poland)

Bipartite states with vanishing quantum discord are necessarily separable and hence positive partial transpose (PPT). We show that 2xN states satisfy additional property: the positivity of their partial transposition is recognized with respect to the canonical factorization of the original density operator. We call such states strong PPT (SPPT). Therefore, we provide a natural witness for a quantum discord: if a 2xN state is not SPPT it must contain nonclassical correlations measured by quantum discord. It is an analog of the celebrated Peres-Horodecki criterion: if a state is not PPT it must be entangled.

• OSTI ID: 21407890
• Journal Information: Physical Review. A, Vol. 81, Issue 6; Other Information: DOI: 10.1103/PhysRevA.81.062102; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CORRELATIONS
DENSITY MATRIX
FACTORIZATION
QUANTUM ENTANGLEMENT
QUANTUM OPERATORS
MATHEMATICAL OPERATORS
MATRICES