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arXiv · 1109.0147

Decoherence and the Nature of System-Environment Correlations

A. Pernice·W. T. Strunz
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Abstract

We investigate system-environment correlations based on the exact dynamics of a qubit and its environment in the framework of pure decoherence (phase damping). We focus on the relation of decoherence and the build-up of system-reservoir entanglement for an arbitrary (possibly mixed) initial qubit state. In the commonly employed regime where the qubit dynamics can be described by a Markov master equation of Lindblad type, we find that for almost all qubit initial states inside the Bloch sphere, decoherence is complete while the total state is still separable - no entanglement is involved. In general, both "separable" and "entangling" decoherence occurs, depending on temperature and initial qubit state. Moreover, we find situations where classical and quantum correlations periodically alternate as a function of time in the regime of low temperatures.

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A. Pernice, W. T. Strunz. 2011-11-08. Decoherence and the Nature of System-Environment Correlations. https://doi.org/10.1103/physreva.84.062121

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