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arXiv · 0908.2497

Momentum dependence of orbital excitations in Mott-insulating titanates

C. Ulrich·L. J. P. Ament·G. Ghiringhelli·L. Braicovich·M. Moretti Sala·N. Pezzotta·T. Schmitt·G. Khaliullin·J. van den Brink·H. Roth·T. Lorenz·B. Keimer
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Abstract

High-resolution resonant inelastic x-ray scattering has been used to determine the momentum dependence of orbital excitations in Mott-insulating LaTiO$_3$ and YTiO$_3$ over a wide range of the Brillouin zone. The data are compared to calculations in the framework of lattice-driven and superexchange-driven orbital ordering models. A superexchange model in which the experimentally observed modes are attributed to two-orbiton excitations yields the best description of the data.

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C. Ulrich, L. J. P. Ament, G. Ghiringhelli, L. Braicovich, M. Moretti Sala, N. Pezzotta, T. Schmitt, G. Khaliullin, J. van den Brink, H. Roth, T. Lorenz, B. Keimer. 2009-08-18. Momentum dependence of orbital excitations in Mott-insulating titanates. https://doi.org/10.1103/physrevlett.103.107205

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