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arXiv · 1908.09247

Spin-reorientation critical dynamics in the two-dimensional XY model with a domain wall

X. W. Lei·N. J. Zhou·Y. Y. He·B. Zheng
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Abstract

In recent years, static and dynamic properties of non-$180^\circ$ domain walls in magnetic materials have attracted a great deal of interest. In this paper, spin-reorientation critical dynamics in the two-dimensional XY model is investigated with Monte Carlo simulations and theoretical analyses based on the Langevin equation. At the Kosterlitz-Thouless phase transition, dynamic scaling behaviors of the magnetization and the two-time correlation function are carefully analyzed, and critical exponents are accurately determined. When the initial value of the angle between adjacent domains is slightly lower than $π$, a critical exponent is introduced to characterize the abnormal power-law increase of the magnetization in the horizontal direction inside the domain interface, which is measured to be $ψ=0.0568(8)$. Besides, the relation $ψ=η/2z$ is analytically deduced from the Langevin dynamics in the long-wavelength approximation, well consistent with numerical results.

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X. W. Lei, N. J. Zhou, Y. Y. He, B. Zheng. 2019-08-25. Spin-reorientation critical dynamics in the two-dimensional XY model with a domain wall. https://doi.org/10.1103/physreve.99.022129

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