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arXiv · 1006.4838

Field-induced decay dynamics in square-lattice antiferromagnet

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

Dynamical properties of the square-lattice Heisenberg antiferromagnet in applied magnetic field are studied for arbitrary value S of the spin. Above the threshold field for two-particle decays, the standard spin-wave theory yields singular corrections to the excitation spectrum with logarithmic divergences for certain momenta. We develop a self-consistent approximation applicable for S >= 1, which avoids such singularities and provides regularized magnon decay rates. Results for the dynamical structure factor obtained in this approach are presented for S = 1 and S = 5/2.

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M. Mourigal, M. E. Zhitomirsky, A. L. Chernyshev. 2010-10-01. Field-induced decay dynamics in square-lattice antiferromagnet. https://doi.org/10.1103/physrevb.82.144402

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