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

R. G. Pereira (1) , J. Sirker (2) , J. -S. Caux (3) , R. Hagemans (3) , Jean Michel Maillet (4) , S. R. White (5) , I. Affleck (1)

1 Univ British Columbia, Dept Phys & Astron
2 Max Planck Institute for Solid State Research
3 IFTA - Institute for Theoretical Physics [Amsterdam]
4 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
5 Department of Physics and Astronomy [Irvine]

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.

Keywords: Integrable models; Bethe ansatz; Correlation functions; spin chain

Domains: Physics [physics]; Condensed Matter [cond-mat]; Other [cond-mat.other]; Physics [physics]; Mathematical Physics [math-ph]; Mathematics [math]; Mathematical Physics [math-ph]

R. G. Pereira, J. Sirker, J. -S. Caux, R. Hagemans, Jean Michel Maillet, et al.. The dynamical spin structure factor for the anisotropic spin-1/2 Heisenberg chain. Physical Review Letters, 2006, 96 (257202), pp.257202. ⟨10.1103/PhysRevLett.96.257202⟩. ⟨ensl-00266542⟩