Abstract
Time-of-flight spectrocopy using neutrons produced by a spallation source is used to measure the one-magnon scattering throughout the Brillouin zone for . The zone-boundary magnons have an energy ħ=0.312±0.005 eV and are good eigenstates of the quantum Heisenberg Hamiltonian in that they possess lifetimes >10/ω. A multiplicative renormalization of the overall frequency scale of classical spin-wave theory accounts for the quantum effects in the one-magnon spectrum.
- Received 30 July 1991
DOI:https://doi.org/10.1103/PhysRevLett.67.3622
©1991 American Physical Society