Spin dynamics of the model 2D quantum antiferromagnet CFTD

H. M. Ronnow; D. F. McMorrow; R. Coldea; A. Harrison; I. D. Youngson; T. G. Perring; G. Aeppli; O. Syljyasen; K. Lefmann; C. Rischel

arXiv · cond-mat/0101238

Spin dynamics of the model 2D quantum antiferromagnet CFTD

H. M. Ronnow·D. F. McMorrow·R. Coldea·A. Harrison·I. D. Youngson·T. G. Perring·G. Aeppli·O. Syljyasen·K. Lefmann·C. Rischel

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Abstract

The magnetic excitation spectrum in the two-dimensional (2D) S=1/2 Heisenberg antiferromagnet copper deuteroformate tetradeuterate (CFTD) has been measured for temperatures up to T\sim J/2, where J=6.31+-0.02 meV is the 2D exchange coupling. For T\ll J, a dispersion of the zone boundary energy is observed, which is attributed to a wavevector dependent quantum renormalization. At higher temperatures, spin-wave-like excitations persist, but are found to broaden and soften. By combining our data with numerical calculations, and with existing theoretical work, a consistent description of the behaviour of the model system is found over the whole temperature interval investigated.

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H. M. Ronnow, D. F. McMorrow, R. Coldea, A. Harrison, I. D. Youngson, T. G. Perring, G. Aeppli, O. Syljyasen, K. Lefmann, C. Rischel. 2001-01-16. Spin dynamics of the model 2D quantum antiferromagnet CFTD. https://arxiv.org/abs/cond-mat/0101238

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