Spin dynamics and orbital state in LaTiO3
A neutron scattering study of the Mott-Hubbard insulator LaTiO3 ( T(N) = 132 K) reveals a spin wave spectrum that is well described by a nearest-neighbor superexchange constant J = 15.5 meV and a small Dzyaloshinskii-Moriya interaction ( D = 1.1 meV). 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 LaTiO3.
Keimer
B
Max-Planck-Institut fur Festkorperforschung, 70569 Stuttgart, Germany and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
Casa
D
Ivanov
A
Lynn
JW
Zimmermann
M
Hill
JP
Gibbs
D
Taguchi
Y
Tokura
Y