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arXiv · 2206.05960

Quasiballistic transport in long-range anisotropic Heisenberg model

M. Mierzejewski·J. Wronowicz·J. Pawłowski·J. Herbrych
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Abstract

Purely ballistic transport is a rare feature even for integrable models. By numerically studying the Heisenberg chain with the power-law exchange, \mbox{$J\propto1/r^\alpha$}, where $r$ is a distance, we show that for spin anisotropy $\Delta \simeq \exp(-\alpha+2)$ the system exhibits a quasiballistic spin transport and the presence of fermionic excitation which do not decay up to extremely long times $\sim10^3/J$. This conclusion is reached on the base of the dynamics of spin domains, the dynamical spin conductivity, inspecting the matrix elements of the spin-current operator, and by the analysis of most conserved operators. Our results smoothly connects two models where fully ballistic transport is present: free particles with nearest-neighbor hopping and the isotropic Haldane-Shastry model.

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M. Mierzejewski, J. Wronowicz, J. Pawłowski, J. Herbrych. 2022-06-13. Quasiballistic transport in long-range anisotropic Heisenberg model. https://doi.org/10.1103/physrevb.107.045134

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