Localised spin waves in disordered ferromagnetic chains
- 30 March 1987
- journal article
- Published by IOP Publishing in Journal of Physics C: Solid State Physics
- Vol. 20 (9) , 1309-1314
- https://doi.org/10.1088/0022-3719/20/9/020
Abstract
Spin waves in two disordered ferromagnetic 1D models are studied by means of a direct diagonalisation and of a decimation technique. In the first model the exchange couplings are absolute values of the gaussian numbers (unit dispersion). In the second model Jij are uniformly distributed between 0.1 and 1.1. This yields, as opposed to the first model, a finite (1/J). It is only for this second case that Theodorou (1982) has predicted the existence of extended spin waves. The authors' studies show that there is no qualitative difference between the two models. For a finite-sized system there is a 'mobility edge' separating extended from localised states but its position shifts towards zero with increasing size. For an infinite system, in both models, there are no truly extended states, at least at energies exceeding 0.003.Keywords
This publication has 9 references indexed in Scilit:
- Random walking on a fractalPhysical Review A, 1984
- Numerical studies of the isotropic Heisenberg model for random ferromagnets and spin glassesJournal of Physics C: Solid State Physics, 1984
- Diffusion on the Sierpiński gaskets: A random walker on a fractally structured objectPhysical Review A, 1984
- Spin waves in random one-dimensional ferromagnetsJournal of Physics C: Solid State Physics, 1982
- Theories of electrons in one-dimensional disordered systemsAdvances in Physics, 1982
- Excitation dynamics in random one-dimensional systemsReviews of Modern Physics, 1981
- Resistance fluctuations in disordered one-dimensional conductorsJournal of Physics C: Solid State Physics, 1980
- Scaling Theory of Localization: Absence of Quantum Diffusion in Two DimensionsPhysical Review Letters, 1979
- Theoretical and experimental studies on one-dimensional magnetic systemsAdvances in Physics, 1976