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arXiv · 0705.3312

Boson decay and the dynamical structure factor for the XXZ chain at finite magnetic field

J. Sirker·R. G. Pereira·J. -S. Caux·R. Hagemans·J. M. Maillet·S. R. White·I. Affleck
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Abstract

We study the longitudinal dynamical structure factor $S^{zz}(q,ω)$ for the anisotropic spin-1/2 (XXZ) chain at finite magnetic field using bosonization. The leading irrelevant operators in the effective bosonic model stemming from band curvature describe boson decay processes and lead to a high-frequency tail and a finite width $γ_q$ of the on-shell peak for $S^{zz}(q,ω)$. We use the Bethe ansatz to show that $γ_q\sim q^2$ for $q\ll 1$ and to calculate the amplitudes of the leading irrelevant operators in the effective field theory.

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J. Sirker, R. G. Pereira, J. -S. Caux, R. Hagemans, J. M. Maillet, S. R. White, I. Affleck. 2007-05-23. Boson decay and the dynamical structure factor for the XXZ chain at finite magnetic field. https://doi.org/10.1016/j.physb.2007.10.304

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