Magnon delocalization in ferromagnetic chains with long-range correlated disorder
We study one-magnon excitations in a random ferromagnetic Heisenberg chain with long-range correlations in the coupling constant distribution. By employing an exact diagonalization procedure, we compute the localization length of all one-magnon states within the band of allowed energies E. The rando...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2002 |
| País: | España |
| Institución: | Universidad de Castilla-La Mancha |
| Repositorio: | RUIdeRA. Repositorio Institucional de la UCLM |
| OAI Identifier: | oai:ruidera.uclm.es:10578/41179 |
| Acceso en línea: | https://doi.org/10.1103/PhysRevB.65.104416 https://journals.aps.org/prb/abstract/10.1103/PhysRevB.65.104416 https://hdl.handle.net/10578/41179 |
| Access Level: | acceso abierto |
| Palabra clave: | Ferromagnetic chains Long-range correlated disorder Magnon delocalization |
| Sumario: | We study one-magnon excitations in a random ferromagnetic Heisenberg chain with long-range correlations in the coupling constant distribution. By employing an exact diagonalization procedure, we compute the localization length of all one-magnon states within the band of allowed energies E. The random distribution of coupling constants was assumed to have a power spectrum decaying. We found that for<1, one-magnon excitations remain exponentially localized with the localization length diverging as 1/. For=1 a faster divergence of is obtained. For any>1, a phase of delocalized magnons emerges at the bottom of the band. We characterize the scaling behavior of the localization length on all regimes and relate it with the scaling properties of the long-range correlated exchange coupling distribution. |
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