DOI | Trouver le DOI : https://doi.org/10.1103/PhysRevB.66.024407 |
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Auteur | Rechercher : Kenzelmann, M.; Rechercher : Cowley, R. A.; Rechercher : Buyers, W. J. L.1; Rechercher : Tun, Z.1; Rechercher : Coldea, R.; Rechercher : Enderle, M. |
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Affiliation | - Conseil national de recherches du Canada. Centre canadien de faisceaux de neutrons du CNRC
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Format | Texte, Article |
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Résumé | We report inelastic time-of-flight and triple-axis neutron scattering measurements of the excitation spectrum of the coupled antiferromagnetic spin-1 Heisenberg chain system CsNiCl3. Measurements over a wide range of wave-vector transfers along the chain confirm that above TNCsNiCl3 is in a quantum-disordered phase with an energy gap in the excitation spectrum. The spin correlations fall off exponentially with increasing distance with a correlation length ξ=4.0(2) sites at T=6.2K. This is shorter than the correlation length for an antiferromagnetic spin-1 Heisenberg chain at this temperature, suggesting that the correlations perpendicular to the chain direction and associated with the interchain coupling lower the single-chain correlation length. A multiparticle continuum is observed in the quantum-disordered phase in the region in reciprocal space where antiferromagnetic fluctuations are strongest, extending in energy up to twice the maximum of the dispersion of the well-defined triplet excitations. We show that the continuum satisfies the Hohenberg-Brinkman sum rule. The dependence of the multiparticle continuum on the chain wave vector resembles that of the two-spinon continuum in antiferromagnetic spin-1/2 Heisenberg chains. This suggests the presence of spin-1/2 degrees of freedom in
CsNiCl3 for T<~12K, possibly caused by multiply frustrated interchain interactions. |
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Date de publication | 2002-06-28 |
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Dans | |
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Langue | anglais |
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Numéro NPARC | 12338093 |
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Exporter la notice | Exporter en format RIS |
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Signaler une correction | Signaler une correction (s'ouvre dans un nouvel onglet) |
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Identificateur de l’enregistrement | 198f308d-0d08-4977-a6b8-5fcb5beb83da |
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Enregistrement créé | 2009-09-10 |
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Enregistrement modifié | 2020-04-06 |
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