L. Manara, A. Smirne and B. Vacchini,
Non-Markovianity in the Adapted Caldeira-Leggett Model
Int. J. Quantum Inform. vol. xx,
2640004 (2024)
Abstract:
We investigate the non-Markovian features of the Adapted Caldeira–Leggett model, a
computationally efficient framework recently proposed to capture the essential physics
of the standard Caldeira–Leggett model. While this effective model has been previously
validated for decoherence and einselection, its ability to reproduce memory effects
remains to be explored. By exploiting the model's capability to explicitly track both
system and environment degrees of freedom, we provide a detailed characterization of
non-Markovianity through the lens of information backflow. We evaluate the buildup
of system-environment correlations and the corresponding modifications of the environmental
state, assessing a quantitative upper bound for the revival of distinguishability
in the reduced dynamics. Our results, obtained by comparing different distinguishability
quantifiers such as trace distance and the square root of the Jensen-Shannon divergence,
show that while correlations are primarily sensitive to coupling strength, environmental
state changes are more heavily influenced by temperature. Our analysis substantiates
the physical interpretation of the distinguishability-based approach to non-Markovianity,
and confirms this variant of the Caldeira–Leggett model as a reliable tool for exploring
the microscopic origins of different fundamental phenomena in quantum mechanics.
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