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arXiv · 2106.08237

Non-equilibrium dynamics of the open quantum $O(n)$-model with non-Markovian noise: exact results

Sascha Wald·Malte Henkel·Andrea Gambassi
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Abstract

The collective and purely relaxational dynamics of quantum many-body systems after a quench at temperature $T=0$, from a disordered state to various phases is studied through the exact solution of the quantum Langevin equation of the spherical and the $O(n)$-model in the limit $n\to\infty$. The stationary state of the quantum dynamics is shown to be a non-equilibrium state. The quantum spherical and the quantum $O(n)$-model for $n\to\infty$ are in the same dynamical universality class. The long-time behaviour of single-time and two-time correlation and response functions is analysed and the universal exponents which characterise quantum coarsening and quantum ageing are derived. The importance of the non-Markovian long-time memory of the quantum noise is elucidated by comparing it with an effective Markovian noise having the same scaling behaviour and with the case of non-equilibrium classical dynamics.

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Sascha Wald, Malte Henkel, Andrea Gambassi. 2021-09-07. Non-equilibrium dynamics of the open quantum $O(n)$-model with non-Markovian noise: exact results. https://doi.org/10.1088/1742-5468%2Fac25f6

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