Weak three-dimensional coupling of Heisenberg quantum spin chains in SrCuTe2O6
| Autor: | Robert Bewley, S. Chillal, P. Steffens, Bella Lake, A. T. M. N. Islam |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Physical Review B. 104 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.104.144402 |
| Popis: | The magnetic Hamiltonian of the Heisenberg quantum antiferromagnet $\mathrm{Sr}\mathrm{Cu}{\mathrm{Te}}_{2}{\mathrm{O}}_{6}$ is studied by inelastic neutron scattering technique on powder and single-crystalline samples above and below the magnetic transition temperatures at 8 and 2 K. The high-temperature spectra reveal a characteristic diffuse scattering corresponding to a multispinon continuum, confirming the dominant quantum spin chain behavior due to the third neighbor interaction ${J}_{\text{intra}}=4.22$ meV (49 K). The low-temperature spectra exhibit sharper excitations at energies 1.25 meV, which can be explained by considering a combination of weak antiferromagnetic first nearest neighbor interchain coupling ${J}_{1}=0.17$ meV ($1.9$ K) and even weaker ferromagnetic second nearest neighbor ${J}_{2}=\ensuremath{-}0.037$ meV ($\ensuremath{-}0.4$ K) or a weak ferromagnetic ${J}_{2}=\ensuremath{-}0.11$ meV ($\ensuremath{-}1.3$ K) and antiferromagnetic ${J}_{6}=0.16$ meV ($1.85$ K), giving rise to the long-range magnetic order and spin-wave excitations at low energies. These results suggest that $\mathrm{Sr}\mathrm{Cu}{\mathrm{Te}}_{2}{\mathrm{O}}_{6}$ is a highly one-dimensional Heisenberg system with three mutually perpendicular spin chains coupled by a weak ferromagnetic ${J}_{2}$ in addition to the antiferromagnetic ${J}_{1}$ or ${J}_{6}$, presenting a contrasting scenario from the highly frustrated hyper-hyperkagome lattice (equally strong antiferromagnetic ${J}_{1}$ and ${J}_{2}$) found in the isostructural quantum spin liquid candidate $\mathrm{Pb}\mathrm{Cu}{\mathrm{Te}}_{2}{\mathrm{O}}_{6}$ . |
| Databáze: | OpenAIRE |
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