Orbital Ordering and Orbital Fluctuations in Transition Metal Oxides

Abstract

We summarize some characteristic features of the frustrated magnetic interactions in spin-orbital models adequate for cubic transition metal oxides with orbital degeneracy. A generic tendency towards dimerization, found already in the degenerate Hubbard model, is confirmed for $t_{2g}$ but not for $e_g$ systems. In the $t_{2g}$ case the quantum orbital fluctuations are more pronounced and contribute to a stronger competition between different magnetic and orbital states. Therefore the orbital liquid states exist in some undoped $t_{2g}$ systems, while in the manganites such states can be triggered only by doping.

9 pages, 5 figures

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Cited by in corpus (4)

• Fingerprints of spin-orbital physics in cubic Mott insulators: Magnetic exchange interactions and optical spectral weights
• Orbital liquid in ferromagnetic manganites: The orbital Hubbard model for $e_g$ electrons
• Orbital polarons versus itinerant e_g electrons in doped manganites
• One-dimensional orbital fluctuations and the exotic magnetic properties of YVO${}_3$