title: Two-spinon and four-spinon continuum in a frustrated ferromagnetic spin-1/2 chain.
abstract: Inelastic neutron scattering measurements show the existence of a strong two-spinon continuum in the frustrated ferromagnetic spin-1/2 chain compound LiCuVO4. The dynamic magnetic susceptibility is well described by a mean-field model of two coupled interpenetrating antiferromagnetic Heisenberg chains. The extracted values of the exchange integrals are in good agreement with the static magnetic susceptibility data and an earlier spin-wave description of the bound state near the lower boundary of the two-spinon continuum. In addition, there is clear evidence for a four-spinon continuum at high energies.
authors.affiliation: Institut Laue Langevin, BP156, 6 rue Horowitz, 38042 Grenoble, France.
authors.forename: M
authors.initials: M
authors.lastname: Enderle
authors.forename: B
authors.initials: B
authors.lastname: Fåk
authors.forename: H-J
authors.initials: HJ
authors.lastname: Mikeska
authors.forename: R K
authors.initials: RK
authors.lastname: Kremer
authors.forename: A
authors.initials: A
authors.lastname: Prokofiev
authors.forename: W
authors.initials: W
authors.lastname: Assmus