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 =π 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.
Physical Review B
- Pub Date:
- July 2018
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Quantum Gases
- submitted version, 12 pages, 2 figures, latest version and more information can be found at https://www.physik.uni-kl.de/eggert/papers/index.html