Two-spinon and four-spinon continuum in a frustrated ferromagnetic spin-1/2 chain.
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.
Enderle
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Institut Laue Langevin, BP156, 6 rue Horowitz, 38042 Grenoble, France.
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Mikeska
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Kremer
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Prokofiev
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Assmus
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