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arXiv · 2303.16632

Universality in relaxation of spin helices under the $XXZ$- spin chain dynamics

Vladislav Popkov·Marko Žnidarič·Xin Zhang
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Abstract

We describe dynamics of transverse spin-helix state (SHS) -- a product state with spatially rotating magnetization -- under anisotropic Heisenberg XXZ spin chain evolution. Due to experimental relevance we especially focus on magnetization dynamics. At long times the $U(1)$ symmetry of the Hamiltonian is restored, leading to the decay of transverse magnetization, which can be described as an exponential decay of a spatially harmonic profile. We show that the dependence of the short and intermediate-time decay timescale, which in principle depends on all different parameters, like the wavevector of the initial helix, the anisotropy, etc., can be described well by a single scaling function. We also briefly discuss the evolution of magnetization current.

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Vladislav Popkov, Marko Žnidarič, Xin Zhang. 2023-03-29. Universality in relaxation of spin helices under the $XXZ$- spin chain dynamics. https://doi.org/10.1103/physrevb.107.235408

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