Magnon mode transition in real space

Spin excitation of an ilmenite FeTiO 3 powder sample is measured by time-of-flight inelastic neutron scattering. The dynamic magnetic pair-density function D M ( r, E ) is obtained from the dynamic magnetic structure factor S M ( Q, E ) by the Fourier transformation. The real space spin dynamics exhibit magnon mode transitions in the spin-spin correlation with increasing energy from no-phase-shift to p-phase-shift. The mode transition is a unique feature in this real space image, which does not correspond directly to the reciprocal space magnon dispersions. This analysis provides a novel opportunity to study the local spin dynamics of various magnetic systems.