S. V. Streltsov

Orbital-Assisted Metal-Insulator Transition in VO2

We found direct experimental evidence for an orbital switching in the V 3d states across the metal-insulator transition in VO2. We have used soft-x-ray absorption spectroscopy at the V L2,3 edges as a sensitive local probe and have determined quantitatively the orbital polarizations. These results strongly suggest that, in going from the metallic to the insulating state, the orbital occupation changes in a manner that charge fluctuations and effective bandwidths are reduced, that the system becomes more one dimensional and more susceptible to a Peierls-like transition, and that the required massive orbital switching can only be made if the system is close to a Mott insulating regime.

Influence of rare-earth ion radii on the low-spin to intermediate-spin state transition in lanthanide cobaltite perovskites: LaCoO 3 versus HoCoO 3

We present first-principles (local-density approximation) LDA+U calculations of electronic structure and magnetic state for

Valence bond liquid phase in the honeycomb lattice material Li2RuO3

{\mathrm{LaCoO}}_{3}

Coulomb correlation effects in LaFeAsO: An LDA + DMFT(QMC) study

and

Crystal-field splitting for low symmetry systems in ab initio calculations

{\mathrm{HoCoO}}_{3}.

Magnetic phase diagram and first-principles study ofPb3TeCo3V2O14

Low-spin to intermediate-spin state transition was found in our calculations using experimental crystallographic data for both materials with a much higher transition temperature for

Electronic Raman scattering and the electron–phonon interaction in YB6

{\mathrm{HoCoO}}_{3},

Spin-orbital interaction for face-sharing octahedra: Realization of a highly symmetric SU(4) model

which agrees well with the experimental estimations. Low-spin state

Robust singlet dimers with fragile ordering in two-dimensional honeycomb lattice of Li2RuO3.

{t}_{2g}^{6}{e}_{g}^{0}

Role of local geometry in spin and orbital structure of transition metal compounds

(nonmagnetic) to intermediate-spin state