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arXiv · 2112.08158

Multiple relaxation times in perturbed XXZ chain

M. Mierzejewski·J. Pawłowski·P. Prelovšek·J. Herbrych
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Abstract

We numerically study the relaxation of correlation functions in weakly perturbed integrable XXZ chain. The decay of the spin-current and the energy-current correlations at zero magnetization are well described by single, but quite distinct, relaxation rates governed by the square of the perturbation strength $g$. However, at finite magnetization a single correlation function reveals multiple relaxation rates. The result can be understood in terms of multi-scale relaxation scenario, where various relaxation times are linked with various quantities which are conserved in the reference integrable system. On the other hand, the correlations of non-commuting quantities, being conserved at particular anisotropies $\Delta$, decay non-exponentially with characteristic time scale linear in $g$.

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M. Mierzejewski, J. Pawłowski, P. Prelovšek, J. Herbrych. 2021-12-15. Multiple relaxation times in perturbed XXZ chain. https://doi.org/10.21468/scipostphys.13.2.013

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