相关论文: Charge and orbital order in transition metal oxide…
We show that an interplay of double exchange and impurity randomness can explain the competition between metal-ferromagnetic and insulating charge ordered states in doped manganites. The double exchange is simplified in the Ising type,…
We establish a novel mechanism of stripe formation in doped systems with alternating $t_{2g}$ orbital order --- the stripe takes the form of a ferro-orbitally ordered domain wall separating domains with staggered order and allowing for…
Copper oxide high temperature superconductors universally exhibit multiple forms of electronically ordered phases that break the native translational symmetry of the CuO2 planes. The interplay between these orders and the superconducting…
In-plane anisotropic ground states are ubiquitous in correlated solids such as pnictides, cuprates and manganites. They can arise from doping Mott insulators and compete with phases such as superconductivity, however their origins are…
The low-temperature properties of the so-called ''charge ordered'' state in 50% doped perovskite manganites are described from the viewpoint of the magnetic spin ordering. In these systems, the zigzag antiferromagnetic ordering, combined…
The phase diagram of half-doped manganite systems of formula A_{0.5}A'_{0.5}MnO_3 is investigated within a single-orbital model incorporating magnetic double-exchange and superexchange, together with intersite Coulomb and electron-lattice…
The formalism of composite and intertwined orders has been remarkably successful in discussing the complex phase diagrams of strongly correlated materials and high-$T_c$ superconductors. Here, we propose that composite orders are also…
We show that in manganites close to half-doping novel non-bipartite magnetic phases appear due to the interplay between double exchange, superexchange and orbital ordering. In considerable part of the phase diagram the groundstate has a…
We argue that, at low temperatures and well into the ferromagnetic phase, the physics of the manganase perovskites may be characterized by a correlated metallic state near a metal insulator transition where the orbital degrees of freedom…
We present the theory of orbital ordering in orbital-degenerate itinerant electron systems. After proposing the criterion of instability for orbital ordering or orbital density wave ordering, we find that the orbital and the spin-orbital…
We studied the ferroelectricity of magnetic oxides in which its emergence coincides with the onset of a second incommensurate magnetic order. We solved for the wave function of e_{g} electrons in the presence of magnetic orders. The…
Motivated by recent experimental suggestions of charge-order-driven ferroelectricity in organic charge-transfer salts, such as $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Cl, we investigate magnetic and charge-ordered phases that emerge in an…
We argue that aspects of the anomalous, low temperature, spin and charge dynamics of the high temperature superconductors can be understood by studying the corresponding physics of undoped Mott insulators. Such insulators display a quantum…
We investigate the magnetic instabilities of the two-dimensional model of interacting e_g electrons for hole doping away from two electrons per site in the mean-field approximation. In particular, we address the occurrence of orbitally…
We review our recent x-ray scattering studies of charge and orbital order in doped manganites, with specific emphasis on the role of orbital correlations in Pr_1-xCa_xMnO_3. For x=0.25, we find an orbital structure indistinguishable from…
The interactions between charge and orbitally ordered $d$-electrons are important in many transition metal oxides. We propose an effective energy model for such interactions, parameterized with DFT+U calculations, so that energy…
A simple model of charge ordering is considered. It is shown explicitly that at any deviation from half-filling ($n \neq 1/2$) the system is unstable with respect to phase separation into charge ordered regions with $n = 1/2$ and metallic…
The shape of 3$d$-orbitals often governs the electronic and magnetic properties of correlated transition metal oxides. In the superconducting cuprates, the planar confinement of the $d_{x^2-y^2}$ orbital dictates the two-dimensional nature…
Correlation between orbital structure and magnetic ordering in bilayered manganites is examined. A level separation between the $3d_{3z^2-r^2}$ and $3d_{x^2-y^2}$ orbitals in a Mn ion is calculated in the ionic model for a large number of…
It is shown that charge ordering in layered crystalline metals causes an increase in the normal state energy of the conducting layers. If this increase in the energy exceeds the difference between the superconducting state energy and the…