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Spin diffusion and the spin 1/2 XXZ chain at $T=\infty$ from exact diagonalization

Klaus Fabricius·Barry M. McCoy
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Abstract

We study the long time behavior of the zz and xx time dependent autocorrelation function of the spin 1/2 XXZ chain at $T=\infty$ by exact diagonalizations on a chain of 16 sites. We find that the numerical results for the zz correlation are very well fit by the formula $t^{-d}[A+Be^{-γ(t-t_0)}\cos Ω(t-t_0)].$ From this we estimate $d$ as a function of the anisotropy of the chain and study the crossover from ballistic to diffusive behavior.

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Klaus Fabricius, Barry M. McCoy. 1997-11-25. Spin diffusion and the spin 1/2 XXZ chain at $T=\infty$ from exact diagonalization. https://doi.org/10.1103/physrevb.57.8340

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