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arXiv · 2107.04505

Quasi-conserved charges in the perturbed spin-1/2 XXX model

Denis V. Kurlov·Savvas Malikis·Vladimir Gritsev
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Abstract

We consider the isotropic spin-$1/2$ Heisenberg spin chain weakly perturbed by a local translationally- and $SU(2)$-invariant perturbation. Starting from the local integrals of motion of the unperturbed model, we modify them in order to obtain quasi-conserved integrals of motion (charges) for the perturbed model. Such quasi-conserved quantities are believed to be responsible for the existence of the prethermalization phase at intermediate timescales. We find that for a sufficiently local perturbation the quasi-conserved quantities indeed exist, and we construct an explicit form for the first few of them.

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Denis V. Kurlov, Savvas Malikis, Vladimir Gritsev. 2021-07-09. Quasi-conserved charges in the perturbed spin-1/2 XXX model. https://doi.org/10.1103/physrevb.105.104302

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