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arXiv · 0705.0523

Quantum spin correlations in an organometallic alternating sign chain

M. B. Stone·W. Tian·M. D. Lumsden·G. E. Granroth·D. Mandrus·J. -H. Chung·N. Harrison·S. E. Nagler
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Abstract

High resolution inelastic neutron scattering is used to study excitations in the organometallic magnet DMACuCl$_3$. The correct magnetic Hamiltonian describing this material has been debated for many years. Combined with high field bulk magnetization and susceptibility studies, the new results imply that DMACuCl$_3$ is a realization of the $S=1/2$ alternating antiferromagnetic-ferromagnetic (AFM-FM) chain. Coupled-cluster calculations are used to derive exchange parameters, showing that the AFM and FM interactions have nearly the same strength. Analysis of the scattering intensities shows clear evidence for inter-dimer spin correlations, in contrast to existing results for conventional alternating chains. The results are discussed in the context of recent ideas concerning quantum entanglement.

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M. B. Stone, W. Tian, M. D. Lumsden, G. E. Granroth, D. Mandrus, J. -H. Chung, N. Harrison, S. E. Nagler. 2007-05-03. Quantum spin correlations in an organometallic alternating sign chain. https://doi.org/10.1103/physrevlett.99.087204

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