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Spin-lattice interaction in the quasi one-dimensional helimagnet LiCu_2O_2

L. Mihály·B. Dóra·A. Ványolos·H. Berger·L. Forró
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Abstract

The field dependence of the electron spin resonance in a helimagnet, LiCu_2O_2, was investigated for the first time. In the paramagnetic state a broad resonance line was observed corresponding to a g-factor of 2.3. In the critical regime around the paramagnetic to helimagnetic phase transition the resonance broadens and shifts to higher frequencies. A narrow signal is recovered at low temperature, corresponding to a spin gap of 1.5 meV in zero field. A comprehensive model of the magnons is presented, using exchange parameters from neutron scattering (T. Masuda et al, Phys. Rev. B 72, 014405), and the spin anisotropy determined here. The role of the quantum fluctuations is discussed.

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L. Mihály, B. Dóra, A. Ványolos, H. Berger, L. Forró. 2006-01-31. Spin-lattice interaction in the quasi one-dimensional helimagnet LiCu_2O_2. https://doi.org/10.1103/physrevlett.97.067206

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