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The dynamical spin structure factor for the anisotropic spin-1/2 Heisenberg chain

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

The longitudinal spin structure factor for the XXZ-chain at small wave-vector q is obtained using Bethe Ansatz, field theory methods and the Density Matrix Renormalization Group. It consists of a peak with peculiar, non-Lorentzian shape and a high-frequency tail. We show that the width of the peak is proportional to q^2 for finite magnetic field compared to q^3 for zero field. For the tail we derive an analytic formula without any adjustable parameters and demonstrate that the integrability of the model directly affects the lineshape.

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R. G. Pereira, J. Sirker, J. -S. Caux, R. Hagemans, J. M. Maillet, S. R. White, I. Affleck. 2006-06-28. The dynamical spin structure factor for the anisotropic spin-1/2 Heisenberg chain. https://doi.org/10.1103/physrevlett.96.257202

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