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Magnon Decay in Noncollinear Quantum Antiferromagnets

A. L. Chernyshev·M. E. Zhitomirsky
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Abstract

Instability of the excitation spectrum of an ordered noncollinear Heisenberg antiferromagnet (AF) with respect to spontaneous two-magnon decays is investigated. We use a spin-1/2 AF on a triangular lattice as an example and examine the characteristic long- and short wave-length features of its zero-temperature spectrum within the 1/S-approximation. The kinematic conditions are shown to be crucial for the existence of decays and for overall properties of the spectrum. The XXZ and the J-J' generalizations of the model, as well as the role of higher-order corrections are discussed.

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A. L. Chernyshev, M. E. Zhitomirsky. 2006-11-14. Magnon Decay in Noncollinear Quantum Antiferromagnets. https://doi.org/10.1103/physrevlett.97.207202

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