Flávia B. Ramos, Andrew Urichuk, Imke Schneider, and Jesko Sirker:
Phys. Rev. B 107, 075138 (2023)
🔓 arXiv:2211.09204 (2022)
We investigate the relaxation dynamics of equal-time correlations in the antiferromagnetic phase of the XXZ spin-1/2 chain following a global quantum quench of the anisotropy parameter. We focus, in particular, on the relaxation dynamics starting from an initial Néel state. Using state-of-the-art density-matrix renormalization group simulations, the exact solution of an effective free-fermion model, and the quench-action approach within the thermodynamic Bethe ansatz, we show that the late-time relaxation is characterized by a power-law decay ~t−3/2 independent of anisotropy. This is in contrast to the previously studied exponential decay of the antiferromagnetic order parameter. Remarkably, the effective model describes the numerical data extremely well even on a quantitative level if higher-order corrections to the leading asymptotic behavior are taken into account.