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arXiv · 0709.4379

Spin-liquid dynamics of pyrochlore magnets Gd2Ti2O7 and Gd2Sn2O7

S. S. Sosin·L. A. Prozorova·A. I. Smirnov·P. Bonville·G. Jasmin - Le Bras·O. A. Petrenko
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Abstract

The spin-liquid phase of two highly frustrated pyrochlore magnets Gd2Ti2O7 and Gd2Sn2O7 is probed using electron spin resonance in the temperature range 1.3 - 30 K. The deviation of the absorption line from the paramagnetic position ν=γH observed in both compounds below the Curie-Weiss temperature Θ_CW ~ 10 K, suggests an opening up of a gap in the excitation spectra. On cooling to 1.3 K (which is above the ordering transition T_N ~ 1.0 K) the resonance spectrum is transformed into a wide band of excitations with the gap amounting to Δ~ 26 GHz (1.2 K) in Gd2Ti2O7 and 18 GHz (0.8 K) in Gd2Sn2O7. The gaps increase linearly with the external magnetic field. For Gd2Ti2O7 this branch co-exists with an additional nearly paramagnetic line absent in Gd2Sn2O7. These low lying excitations with gaps, which are preformed in the spin-liquid state, may be interpreted as collective spin modes split by the single-ion anisotropy.

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S. S. Sosin, L. A. Prozorova, A. I. Smirnov, P. Bonville, G. Jasmin - Le Bras, O. A. Petrenko. 2007-09-27. Spin-liquid dynamics of pyrochlore magnets Gd2Ti2O7 and Gd2Sn2O7. https://doi.org/10.1103/physrevb.77.104424

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