Annabelle Bohrdt, Kevin Jägering, Sebastian Eggert, and Imke Schneider:
Phys. Rev. B, 98, 020402 (2018)
🔓 arXiv:1711.00010 (2017)
The effects of impurities in spin-1/2 Heisenberg chains have recently experienced a renewed interest due to experimental realizations in solid state systems and ultracold gases. Nonmagnetic impurities lead to effectively isolated finite chain segments with a discrete spectrum and characteristic correlations, which have a distinct effect on the dynamic structure factor. Using bosonization and the numerical density matrix renormalization group, we provide detailed quantitative predictions for the momentum- and energy-resolved structure factor in doped systems. Due to the impurities, spectral weight is shifted away from the antiferromagnetic wave vector k=Ď€ into regions which normally have no spectral weight in the thermodynamic limit. The effect can be quantitatively described in terms of scaling functions, which are derived from a recurrence relation based on bosonization.