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arXiv · 1903.07324

Open Quantum System Dynamics: recovering positivity of the Redfield equation via Partial-Secular Approximation

Donato Farina·Vittorio Giovannetti
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Abstract

We show how to recover complete positivity (and hence positivity) of the Redfield equation via a coarse grain average technique. We derive general bounds for the coarse graining time scale above which the positivity of the Redfield equation is guaranteed. It turns out that a coarse grain time scale has strong impact on the characteristics of the Lamb shift term and implies in general non-commutation between the dissipating and the Hamiltonian components of the generator of the dynamical semi-group. Finally we specify the analysis to a two-level system or a quantum harmonic oscillator coupled to a fermionic or bosonic thermal environment via dipole-like interaction.

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Donato Farina, Vittorio Giovannetti. 2019-03-18. Open Quantum System Dynamics: recovering positivity of the Redfield equation via Partial-Secular Approximation. https://doi.org/10.1103/physreva.100.012107

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