Quantum fluctuations and excitations in antiferromagnetic quasicrystals
Abstract
We study the effects of quantum fluctuations and the excitation spectrum for the antiferromagnetic Heisenberg model on a twodimensional quasicrystal, by numerically solving linear spinwave 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 lowenergy modes, as well as dispersionless highenergy states of multifractal nature. The dynamical spin structure factor, accessible to inelastic neutron scattering, exhibits linearsoft modes at low energies, selfsimilar structures with bifurcations emerging at intermediate energies, and flat bands in highenergy 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.
 Authors:

 Institut fuer Theoretische Physik III, Universitaet Stuttgart, D70550 Stuttgart (Germany)
 Theoretische Physik, ETH Zuerich, CH8093 Zurich (Switzerland)
 Publication Date:
 OSTI Identifier:
 20666241
 Resource Type:
 Journal Article
 Journal Name:
 Physical Review. B, Condensed Matter and Materials Physics
 Additional Journal Information:
 Journal Volume: 71; Journal Issue: 10; Other Information: DOI: 10.1103/PhysRevB.71.104427; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 10980121
 Country of Publication:
 United States
 Language:
 English
 Subject:
 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANTIFERROMAGNETIC MATERIALS; ANTIFERROMAGNETISM; BIFURCATION; EXCITATION; FLUCTUATIONS; HEISENBERG MODEL; INELASTIC SCATTERING; MAGNETIC MOMENTS; MONTE CARLO METHOD; NEUTRON DIFFRACTION; NMR SPECTRA; NUCLEAR MAGNETIC RESONANCE; SPIN; SPIN WAVES; STRUCTURE FACTORS
Citation Formats
Wessel, Stefan, and Milat, Igor. Quantum fluctuations and excitations in antiferromagnetic quasicrystals. United States: N. p., 2005.
Web. doi:10.1103/PhysRevB.71.104427.
Wessel, Stefan, & Milat, Igor. Quantum fluctuations and excitations in antiferromagnetic quasicrystals. United States. doi:10.1103/PhysRevB.71.104427.
Wessel, Stefan, and Milat, Igor. Tue .
"Quantum fluctuations and excitations in antiferromagnetic quasicrystals". United States. doi:10.1103/PhysRevB.71.104427.
@article{osti_20666241,
title = {Quantum fluctuations and excitations in antiferromagnetic quasicrystals},
author = {Wessel, Stefan and Milat, Igor},
abstractNote = {We study the effects of quantum fluctuations and the excitation spectrum for the antiferromagnetic Heisenberg model on a twodimensional quasicrystal, by numerically solving linear spinwave 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 lowenergy modes, as well as dispersionless highenergy states of multifractal nature. The dynamical spin structure factor, accessible to inelastic neutron scattering, exhibits linearsoft modes at low energies, selfsimilar structures with bifurcations emerging at intermediate energies, and flat bands in highenergy 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.},
doi = {10.1103/PhysRevB.71.104427},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {10980121},
number = 10,
volume = 71,
place = {United States},
year = {2005},
month = {3}
}