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Decoherence and thermalization dynamics of a quantum oscillator

V. V. Dodonov·S. S. Mizrahi·A. L. de Souza Silva
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Abstract

We introduce the quantitative measures characterizing the rates of decoherence and thermalization of quantum systems. We study the time evolution of these measures in the case of a quantum harmonic oscillator whose relaxation is described in the framework of the standard master equation, for various initial states (coherent, `cat', squeezed and number). We establish the conditions under which the true decoherence measure can be approximated by the linear entropy $1-{Tr}\hatρ^2$. We show that at low temperatures and for highly excited initial states the decoherence process consists of three distinct stages with quite different time scales. In particular, the `cat' states preserve 50% of the initial coherence for a long time interval which increases logarithmically with increase of the initial energy.

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V. V. Dodonov, S. S. Mizrahi, A. L. de Souza Silva. 2000-04-19. Decoherence and thermalization dynamics of a quantum oscillator. https://doi.org/10.1088/1464-4266/2/3/309

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