Related papers: Strain and Spin-Orbit Coupling Induced Orbital-Ord…
We present the main features of the spin-orbital superexchange which describes the magnetic and optical properties of Mott insulators with orbital degrees of freedom. In contrast to the SU(2) symmetry of spin superexchange, the orbital part…
We propose the concept of "hybridization-switching induced Mott transition" which is relevant to a broad class of ABO$_3$ perovskite materials including BiNiO$_3$ and PbCrO$_3$ which feature extended $6s$ orbitals on the A-site cation (Bi…
Oxides with $4d$/$5d$ transition metal ions are physically interesting for their particular crystalline structures as well as the spin-orbit coupled electronic structures. Recent experiments revealed a series of $4d$/$5d$ transition metal…
We propose a new mechanism for the paramagnetic metal-insulator transition in the layered perovskite Ca$_{2-x}$Sr$_{x}$RuO$_{4}$ (0<x<0.2). The LDA+U approach including spin-orbit coupling is used to calculate the electronic structures. In…
Spin-state ordering - a periodic pattern of ions with different spin-state configurations along a crystal lattice - is a rare phenomenon, and its possible interrelation with other electronic degrees of freedom remains little explored. Here…
Anomalous low temperature electronic and structural behaviour has been discovered in PbRuO3. The structure (space group Pnma, a = 5.56314(1), b = 7.86468(1), c = 5.61430(1) A) and metallic conductivity at 290 K are similar to those of…
Novel interplay of spin-orbit coupling and electron correlations in complex Ir oxides recently emerged as a new paradigm for correlated electron physics. Because of a large spin-orbit coupling of ~0.5 eV, which is comparable to the transfer…
We discuss the notions of spin-orbital polarization and ordering in paramagnetic materials, and address their consequences in transition metal oxides. Extending the combined density functional and dynamical mean field theory scheme to the…
The magnetic structure of Ca$_2$MnReO$_6$ double perovskite is investigated by neutron powder diffraction and bulk magnetization, showing dominant non-collinear Mn magnetic moments [$4.35(7)$ $\mu_B$] that are orthogonally aligned with the…
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…
The metal-insulator transition (MIT) is one of the most dramatic manifestations of electron correlations in materials. Various mechanisms producing MITs have been extensively considered, including the Mott (electron localization via Coulomb…
I study the electronic structure and magnetism of postperovskite CaIrO$_3$ using first-principles calculations. The density functional calculations within the local density approximation without the combined effect of spin-orbit coupling…
The mechanisms that drive metal-to-insulator transitions (MIT) in correlated solids are not fully understood. For example, the perovskite (PV) SrCoO3 is a FM metal while the oxygen-deficient (n-doped) brownmillerite (BM) SrCoO2.5 is an…
We have investigated possible spin and charge ordered states in 3d transition-metal oxides with small or negative charge-transfer energy, which can be regarded as self-doped Mott insulators, using Hartree-Fock calculations on d-p-type…
We report a new tetragonal ground-state for perovskite-structured PbCrO3 from DFT+U calculations, and explain its anomalously large volume. The new structure is stabilized due to orbital ordering of Cr-d in the presence of a large…
The interplay between electron correlation and topology of relativistic electrons may lead to a new stage of the research on quantum materials and emergent functions. The emergence of various collective electronic orderings/liquids, which…
Rare earth perovskites ($R^{3+}$M$^{3+}$O$_3$), with $e_g^1$ electronic occupation of the M $d$ states, display different types of metal-insulator transition. For manganites (M=Mn), metal-insulator transition is usually induced by the…
The concept of spin-orbital entanglement on superexchange bonds in transition metal oxides is introduced and explained on several examples. It is shown that spin-orbital entanglement in superexchange models destabilizes the long-range (spin…
Using the multiband $d-p$ model and unrestricted Hartree-Fock approximation we investigate the electronic structure and spin-orbital order in three-dimensional MnO$_3$ lattice such as realized in LaMnO$_3$. The orbital order is induced and…
The complex oxide heterostructures such as LaAlO3/SrTiO3 (LAO/STO) interface are paradigmatic platforms to explore emerging multi-degrees of freedom coupling and the associated exotic phenomena. In this study, we reveal the effects of…