Date of Original Version
For special coupling ratios, the one‐dimensional (1D) s=1/2 Heisenberg model with antiferromagnetic nearest and next‐nearest neighbor interactions has a pure dimer ground state, and the 1D s=1 Heisenberg model with antiferromagnetic bilinear and biquadratic interactions has an exact valence‐bond‐solid ground state. The recursion method is used to calculate the T=0 spin dynamic structure factor for both models and, for the s=1/2 model, also the dimer dynamic structure factor. New results for line shapes and dynamically relevant dispersions are obtained.
Yongmin Yu and Gerhard Müller. Dynamics of quantum spin systems in dimer and valence-bond-solid ground states stabilized by competing interactions. J. Appl. Phys. 79 (1996), 4629-4631.
Available at: http://dx.doi.org/10.1063/1.361686