Decoherence and entanglement dynamics in fluctuating fields

Journal Article · Thu Apr 15 04:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.042314· OSTI ID:21408574

Helm, Julius; Strunz, Walter T ^[1]

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1. Institut fuer Theoretische Physik, Technische Universitaet Dresden, D-01062 Dresden (Germany)

We study pure phase damping of two qubits due to fluctuating fields. As frequently employed, decoherence is thus described in terms of random unitary (RU) dynamics, that is, a convex mixture of unitary transformations. Based on a separation of the dynamics into an average Hamiltonian and a noise channel, we are able to analytically determine the evolution of both entanglement and purity. This enables us to characterize the dynamics in a concurrence-purity (CP) diagram: We find that RU phase-damping dynamics sets constraints on accessible regions in the CP plane. We show that initial state and dynamics contribute to final entanglement independently.

• OSTI ID: 21408574
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 4 Vol. 81; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DAMPING
DIAGRAMS
EVOLUTION
HAMILTONIANS
INFORMATION
MATHEMATICAL OPERATORS
NOISE
QUANTUM ENTANGLEMENT
QUANTUM INFORMATION
QUANTUM OPERATORS
QUBITS
RANDOMNESS
TRANSFORMATIONS