We elucidate the role of magnon interaction and spontaneous decays in the spin dynamics of the triangular-lattice Heisenberg antiferromagnet by calculating its dynamical structure factor within the spin-wave theory. Explicit theoretical results for neutron-scattering intensity are provided for spins S=1/2 and S=3/2. The dynamical structure factor exhibits unconventional features such as quasiparticle peaks broadened by decays, non-Lorentzian lineshapes, and significant spectral weight redistribution to the two-magnon continuum. This rich excitation spectrum illustrates the complexity of the triangular-lattice antiferromagnet and provides distinctive qualitative and quantitative fingerprints for experimental observation of decay-induced magnon dynamics.
@article{arxiv.1306.1231,
title = {Dynamical structure factor of triangular-lattice antiferromagnet},
author = {M. Mourigal and W. T. Fuhrman and A. L. Chernyshev and M. E. Zhitomirsky},
journal= {arXiv preprint arXiv:1306.1231},
year = {2016}
}
Comments
13 pages, 9 figures; includes a corrected Fig.4(a) to reflect Erratum: Phys. Rev. B 93, 099901 (2016)