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arXiv · 2107.05553

Self-consistent dynamical maps for open quantum systems

Orazio Scarlatella·Marco Schirò
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Abstract

In several cases, open quantum systems can be successfully described using master equations relying on Born-Markov approximations, but going beyond these approaches has become often necessary. In this work, we introduce the NCA and NCA-Markov dynamical maps for open quantum systems, which go beyond these master equations replacing the Born approximation with a self-consistent approximation, known as non-crossing approximation (NCA). These maps are formally similar to master equations, but allow to capture non-perturbative effects of the environment at a moderate extra numerical cost. To demonstrate their capabilities, we apply them to the spin-boson model at zero temperature for both a Ohmic and a sub-Ohmic environment, showing that they can both qualitatively capture its strong-coupling behaviour, and be quantitatively correct beyond standard master equations.

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Orazio Scarlatella, Marco Schirò. 2021-07-12. Self-consistent dynamical maps for open quantum systems. https://doi.org/10.21468/scipostphys.16.1.026

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