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arXiv · 1809.07799

Non-universal critical aging scaling in three-dimensional Heisenberg antiferromagnets

Riya Nandi·Uwe C. Täuber
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Abstract

We numerically investigate the stationary and non-equilibrium critical dynamics in three-dimensional isotropic Heisenberg antiferromagnets. Since the non-conserved staggered magnetization couples dynamically to the conserved magnetization density, we employ a hybrid simulation algorithm that combines reversible spin precession with relaxational Kawasaki spin exchange processes. We measure the dynamic critical exponent and identify a suitable intermediate time window to obtain the aging scaling exponents. Our results support an earlier renormalization group prediction: While the critical aging collapse exponent assumes a universal value, the associated temporal decay exponent in the two-time spin autocorrelation function depends on the initial distribution of the conserved fields; here, specifically on the width of the initial spin orientation distribution.

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Riya Nandi, Uwe C. Täuber. 2019-02-05. Non-universal critical aging scaling in three-dimensional Heisenberg antiferromagnets. https://doi.org/10.1103/physrevb.99.064417

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