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Temperature-dependent spin gap and singlet ground state in BaCuSi2O6

Y. Sasago·K. Uchinokura·A. Zheludev·G. Shirane
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Abstract

Bulk magnetic measurements and inelastic neutron scattering were used to investigate the spin-singlet ground state and magnetic gap excitations in BaCuSi2O6, a quasi-2-dimensional antiferromagnet with a bilayer structure. The results are well described by a model based on weakly interacting antiferromagnetic dimers. A strongly temperature-dependent dispersion in the gap modes was found. We suggest that the observed excitations are analogous to magneto-excitons in light rare-earth compounds, but are an intrinsic property of a simple Heisenberg Hamiltonian for the S=1/2 magnetic bilayer.

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Y. Sasago, K. Uchinokura, A. Zheludev, G. Shirane. 1996-09-05. Temperature-dependent spin gap and singlet ground state in BaCuSi2O6. https://doi.org/10.1103/physrevb.55.8357

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