Spin dynamics in the distorted triangular lattice antiferromagnet α − SrCr 2 O 4

摘要: The spin dynamics in the distorted triangular lattice antiferromagnet $\ensuremath{\alpha}\ensuremath{-}{\mathrm{SrCr}}_{2}{\mathrm{O}}_{4}$ has been investigated by inelastic neutron scattering on a single crystal. wave dispersion mapped out $(0\phantom{\rule{4pt}{0ex}}k\phantom{\rule{4pt}{0ex}}l)$ and $(h\phantom{\rule{4pt}{0ex}}k\phantom{\rule{4pt}{0ex}}0)$ planes, modeled calculations, order to determine intraplane interplane exchange couplings. Comparison with $\ensuremath{\alpha}\ensuremath{-}{\mathrm{CaCr}}_{2}{\mathrm{O}}_{4}$ shows that, despite smaller distortion of $\ensuremath{\alpha}\ensuremath{-}{\mathrm{SrCr}}_{2}{\mathrm{O}}_{4}$, deviation from perfect still affects Sr compound, soft mode, similar one observed Ca counterpart, being (020). Although is further away magnetic phase boundary than its dynamic properties show intriguing features, which are discussed as quantum fluctuations arising two-magnon continuum.