Related papers: Exchange interactions, Jahn-Teller coupling, and m…
We show by extensive Monte Carlo simulations that we need a multi-spin interaction in addition to pairwise interactions in order to reproduce the temperature dependence of the experimental magnetization observed in the perovskite compound…
We study the interplay of strong electron correlations and intra-triangle spin exchange at two-thirds filling of the single-orbital Hubbard model on the decorated honeycomb lattice using rotationally invariant slave bosons. We find that the…
By combining 5d transition-metal oxides showing pronounced spin-orbit interactions and oxide-based heterostructures, we propose rutile-based IrO2/TiO2 superlattices as promising candidates for unconventional electronic properties. By means…
Double perovskite compounds containing 5d transition metal elements have been extensively studied as platforms for multipolar order phenomena stemming from spin-orbit-entangled 5d electrons. In this study, we examine the interplay between…
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…
A gas of strongly interacting spinless p-orbital fermionic atoms in 2D optical lattices is proposed and studied. Several interesting new features are found. In the Mott limit on a square lattice, the gas is found to be described effectively…
We investigate the metal-to-insulator phase transition driven by the density-density electronic interaction in the quarter-filled model on a cubic lattice with two orbitals split by a crystal field. We show that a systematic consideration…
The magnetic anisotropy af a rectangular Cu-O-Cu bond is investigated in second order of the spin-orbit interaction. Such a bond is characteristic for cuprates having edge sharing CuO_2 chains, and exists also in the Cu_3O_4 plane or in…
Motivated by the experimental realization of synthetic spin-orbit coupling for ultracold atoms, we investigate the phase diagram of the Bose Hubbard model in a non-abelian gauge field in two dimensions. Using a strong coupling expansion in…
We present a theoretical analysis of the phase diagram of two--component bosons on an optical lattice. A new formalism is developed which treats the effective spin interactions in the Mott and superfluid phases on the same footing. Using…
Oxide double perovskites wherein octahedra formed by both 3d elements and sp-based heavy elements give rise to unconventional magnetic ordering and correlated quantum phenomena crucial for futuristic applications. Here, by carrying out…
Motivated by the recent activities on the Ni-based diamond lattice antiferromagnet NiRh$_2$O$_4$, we theoretically explore on a general ground the unique spin and orbital physics for the Ni$^{2+}$ ions with a $3d^8$ electron configuration…
Effects of spin-orbit interactions in condensed matter are an important and rapidly evolving topic. Strong competition between spin-orbit, on-site Coulomb and crystalline electric field interactions in iridates drives exotic quantum states…
We discuss a hopping model of electrons between idealized molecular sites with local orbital degeneracy and dynamical Jahn-Teller effect, for crystal field environments of sufficiently high symmetry. For the Mott-insulating case (one…
We deal with a model for high-temperature superconductivity which maintains that in cuprates electrons running in the copper oxide layers, found in lattice of these materials, form spin-singlet bonds with electrons running in the…
The double perovskite Ba$_{2}$NaOsO$_{6}$ (BNOO), an exotic example of a very high oxidation state (heptavalent) osmium $d^1$ compound and also uncommon by being a ferromagnetic Mott insulator without Jahn-Teller (JT) distortion, is modeled…
The presence of a non-centrosymmetric crystal structure and in-plane mirror symmetry allows an Ising spin-orbit coupling to form in some two-dimensional materials. Examples include transition metal dichalcogenide superconductors like…
We theoretically study quasi-two-dimensional nickel compounds, where the nickel ions assume Ni$^{2+}$ $d^8$ valence state and feature a low-spin $S=0$ ground state quasidegenerate with $S=1$ ionic excitations. Such a level structure is…
Recent observations of novel spin-orbit coupled states have generated tremendous interest in $4d/5d$ transition metal systems. A prime example is the $J_{\text{eff}}=\frac{1}{2}$ state in iridate materials and $\alpha$-RuCl$_{3}$ that…
A model interaction is proposed in which pairing is caused by a non-local Jahn-Teller (JT) -like instability due to the coupling between planar O states and knot equal to 0 phonons. Apart from pairing, the interaction is found to naturally…