Abstract
To test the prediction that the dispersion of the magnetic resonance in superconducting is similar to magnons in an incommensurate antiferromagnet, we have mapped out the spin dynamics in a stripe-ordered nickelate, , with , using inelastic neutron scattering. We observe spin-wave excitations up to 80 meV emerging from the incommensurate magnetic peaks with a surprisingly large and almost isotropic spin velocity: . A comparison indicates that the inferred spin-excitation spectrum is not, by itself, an adequate model for the magnetic resonance feature of the superconductor.
- Received 8 March 2002
DOI:https://doi.org/10.1103/PhysRevLett.90.147202
©2003 American Physical Society