Abstract
A neutron scattering study of the Mott-Hubbard insulator ( ) reveals a spin wave spectrum that is well described by a nearest-neighbor superexchange constant and a small Dzyaloshinskii-Moriya interaction ( ). The nearly isotropic spin wave spectrum is surprising in view of the absence of a static Jahn-Teller distortion that could quench the orbital angular momentum, and it may indicate strong orbital fluctuations. A resonant x-ray scattering study has uncovered no evidence of orbital order in .
- Received 2 February 2000
DOI:https://doi.org/10.1103/PhysRevLett.85.3946
©2000 American Physical Society