Orbital order and fluctuations in Mott insulators

By G. Khaliullin. 2005

232 citations recorded by the source corpus.

Basic mechanisms controlling orbital order and orbital fluctuations in transition metal oxides are discussed. The lattice driven classical orbital picture, e.g. like in manganites LaMnO$_3$, is contrasted to the quantum behavior of orbitals in frustrated superexchange models as realised in pseudocubic titanites ATiO$_3$ and vanadates AVO$_3$. In YVO$_3$, the lattice and superexchange effects strongly compete -- this explains the extreme sensitivity of magnetic states to temperature and doping. Lifting the $t_{2g}$ orbital degeneracy by a relativistic spin-orbital coupling is considered on example of the layered cobaltates. We find that the spin-orbital mixing of low-energy states leads to unusual magnetic correlations in a triangular lattice of the CoO$_2$ parent compound. Finally, the magnetism of sodium-rich compounds Na$_{1-x}$CoO$_2$ is discussed in terms of a spin/orbital polaronic liquid.

Subfields: Catalysis, Condensed Matter Physics, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/00f32f8355f8b4df408834f51c7ac3d7ac038870

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Catalysis

1. J. van den Brink
2. Zohar Nussinov

In Condensed Matter Physics

1. J. Knolle
2. I. Kimchi
3. J. van den Brink
4. M. Hermanns
5. Zohar Nussinov
6. G. Khaliullin
7. G. Jackeli
8. Simon Trebst

In Electronic, Optical and Magnetic Materials

1. J. Knolle
2. I. Kimchi
3. J. van den Brink
4. M. Hermanns
5. Zohar Nussinov
6. G. Jackeli
7. G. Khaliullin

Citations in the corpus

• Direct evidence for dominant bond-directional interactions in a honeycomb lattice iridate Na2IrO3 (2015, background): “31), and implies that the critical temperature in Na2IrO3 is limited by the anisotropic interactions rather than the interlayer coupling; the Mermin–Wagner theorem requires either the symmetry to be lower than SU(2) or the dimension to be higher than 2D for a finitetemperature phase transition.”
• Physics of the Kitaev Model: Fractionalization, Dynamic Correlations, and Material Connections (2017, background): “[81] George Jackeli and Adolfo Avella.”
• Compass models: Theory and physical motivations (2015, background): “The name orbital compass model was coined at the time, but only in the past decade these models started to receive wide-spread attention to describe physical properties of materials with orbital degrees of freedom (van den Brink, 2004; Khaliullin, 2005; Tokura and Nagaosa, 2000).”