Tunable Magnon Interactions in a Ferromagnetic Spin-1 Chain
Tunable Magnon Interactions in a Ferromagnetic Spin-1 Chain
NiNb$_{2}$O$_{6}$ is an almost ideal realization of a 1D spin-1 ferromagnetic Heisenberg chain compound with weak unidirectional anisotropy. Using time-domain THz spectroscopy, we measure the low-energy electrodynamic response of NiNb$_{2}$O$_{6}$ as a function of temperature and external magnetic field. At low temperatures, we find a magnon-like spin-excitation, which corresponds to …