2004/10/07 by Stefan Wessel, Stefan Weßel, I. Milat +1 · 2 citations
Materials Science · Physics and Astronomy · #Magnetic properties of thin films #Quasicrystal Structures and Properties #Theoretical and Computational Physics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.71.104427
published as Phys. Rev. B 71, 104427 (2005). · RevTex, 12 pages with 15 figures
arxiv created 2004/10/07 · openalex publication_date 2005/03/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the effects of quantum fluctuations and the excitation spectrum for the antiferromagnetic Heisenberg model on a two-dimensional quasicrystal, by numerically solving linear spin-wave theory on finite approximants of the octagonal tiling. Previous quantum Monte Carlo results for the distribution of local staggered magnetic moments and the static spin structure factor are reproduced well within this approximate scheme. Furthermore, the magnetic excitation spectrum consists of magnonlike low-energy modes, as well as dispersionless high-energy states of multifractal nature. The dynamical spin structure factor, accessible to inelastic neutron scattering, exhibits linear-soft modes at low energies, self-similar structures with bifurcations emerging at intermediate energies, and flat bands in high-energy regions. We find that the distribution of local staggered moments stemming from the inhomogeneity of the quasiperiodic structure leads to a characteristic energy spread in the local dynamical spin susceptibility, implying distinct nuclear magnetic resonance spectra, specific for different local environments.