Related papers: Orbital order and fluctuations in Mott insulators
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…
Strongly-correlated transition-metal oxides are widely known for their various exotic phenomena. This is exemplified by rare-earth nickelates such as LaNiO$_{3}$, which possess intimate interconnections between their electronic, spin, and…
We show that the $t_{2g}^2$ perovskite LaVO$_3$, in its orthorhombic phase, is a rare case of a system hosting an orbital-ordering Kugel-Khomskii phase transition, rather than being controlled by the Coulomb-enhanced crystal-field…
We study optical excitations across the Mott gap in the multi-orbital Mott-Hubbard insulators RVO3. The multi-peak structure observed in the optical conductivity can be described consistently in terms of the different 3d^3 multiplets or…
We consider driving multi-orbital Mott insulators using laser radiation. We derive general expressions for periodically driven spin-orbital models using time-dependent perturbation theory in the strong interaction limit. We show that the…
We study a two-dimensional single band Hubbard Hamiltonian with antisymmetric spin-orbit coupling. We argue that this is the minimal model to understand the electronic properties of locally non-centrosymmetric transition-metal (TM) oxides…
We compare the effective spin-orbital super\-exchange triggered by magnetic $3d$ impurities with $d^3$ and $d^2$ configurations and either no orbital degree of freedom (orbital dilution) or hole replacing a doublon (charge dilution) in a…
Emergent magnetic states at oxide interfaces arise from the interplay of charge transfer, orbital reconstruction, and dimensional confinement, offering a route to engineered correlated-electron behavior in nanoscale spintronic materials.…
We present a band structure study of orbital polarization and ordering in the two-dimensional triangular lattice transition metal compounds LiVO_2 and NaTiO_2. It is found that while in NaTiO_2 the degeneracy of t_{2g} orbitals is lifted…
Rare-earth titanates RTiO$_3$ are Mott insulators displaying a rich physical behavior, featuring most notably orbital and spin orders in their ground state. The origin of their ferromagnetic to antiferromagnetic transition as a function of…
A model of chemical bonding between ions in manganites involving covalent one-electron $\sigma$ bonding is suggested. The covalent one-electron $\sigma$ bonding gives rise to a strongly correlated state of electrons resulting from the…
The emergence of superlattice periodicities at metal to insulator transitions in hole doped perovskite oxides responds to a rearrangement of the local atomic structure, and electron and spin density distribution. Originally, the ionic model…
MgV$_{2}$O$_{4}$ is a spinel based on magnetic V$^{3+}$ ions which host both spin ($S=1$) and orbital ($l_{eff}=1$) moments. Owing to the underlying pyrochlore coordination of the magnetic sites, the spins in MgV$_{2}$O$_{4}$ only…
We propose orbital fluctuations in a multi-band ground state as the superconducting pairing mechanism in the new iron-based materials. We develop a general SU(4) theoretical framework for studying a two-orbital model and discuss a number of…
Quantum phase transitions in the two-dimensional Kugel-Khomski model on a square lattice are studied using the plaquette mean field theory and the entanglement renormalization ansatz. When $3z^2-r^2$ orbitals are favored by the crystal…
LaMnO$_3$ is considered as a prototypical Jahn-Teller perovskite compound, exhibiting a metal to insulator transition at $T_{JT} = 750K$ related to the joint appearance of an electronic orbital ordering and a large lattice Jahn-Teller…
We study orbital Mott transition in two dimensional pyrochlore lattice, using a two orbital Hubbard model with only inter-orbital electronic hopping. We use a real space Monte Carlo based approach to study the model at finite temperature,…
Motivated by the energetic advantage of achieving coherent enhancement of effective spin-dependent interactions through approximate nesting, we propose specific forms of spin ordering, whose form varies over the Fermi surface, for the…
The long-standing problem of the effect of correlations on the ferromagnetism of is apparently nearing solution. The ferromagnetism of transition metals compounds, for instance doped manganites, poses a new question: is there some kind of…
In the perovskite Ti oxide RTiO3 (R=rare-earth ions), the Ti t2g orbitals and spins in the 3d^1 state couple each other through the strong electron correlations, resulting in a rich variety of orbital-spin phases. The origin and nature of…