Frozen discord in non-Markovian dephasing channels

Abstract

We investigate the dynamics of quantum and classical correlations in a system of two qubits under local colored-noise dephasing channels. The time evolution of a single qubit interacting with its own environment is described by a memory kernel non-Markovian master equation. The memory effects of the non-Markovian reservoirs introduce new features in the dynamics of quantum and classical correlations compared to the white noise Markovian case. Depending on the geometry of the initial state, the system can exhibit frozen discord and multiple sudden transitions between classical and quantum decoherence [L. Mazzola, J. Piilo and S. Maniscalco, Phys. Rev. Lett. 104 (2010) 200401]. We provide a geometric interpretation of those phenomena in terms of the distance of the state under investigation to its closest classical state in the Hilbert space of the system.

11 pages, 2 figures

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• Quantum non-Markovianity: Overview and recent developments
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• Sudden change in dynamics of genuine multipartite entanglement of cavity-reservoir qubits
• Characterizing qubit channels in the context of quantum teleportation
• Classical memoryless noise-induced maximally discordant mixed separable steady states
• Quantum speed limit time: role of coherence
• The effect of quantum memory on quantum speed limit time for CP-(in)divisible channels
• Decoherence Effects in a Three-Level System under Gaussian Process
• Universal freezing of asymmetry
• Frozen and Invariant Quantum Discord under Local Dephasing Noise