Related papers: Double exchange model in cubic vanadates
We study theoretically the effects of f-d magnetic exchange interaction in the R$_2$Ir$_2$O$_7$ pyrochlore iridates. The R$^{3+}$ f-electrons form localized magnetic doublets due to the crystal field environment, while the Ir$^{4+}$ d-…
Recent quantum-gas microscopy of ultracold atoms and scanning tunneling microscopy of the cuprates reveal new detailed information about doped Mott antiferromagnets, which can be compared with calculations. Using cellular dynamical…
Electronic structure, electrical transport, dc and ac magnetization properties of the hole substituted (Sr2+) partially B-site disordered double perovskite Pr2-xSrxCoMnO6 system have been investigated. Electronic structure was probed by…
A spin-fermion model that captures the charge-transfer properties of Cu-based high critical temperature superconductors is introduced and studied via Monte Carlo simulations. The strong Coulomb repulsion among $d$-electrons in the Cu…
In order to have a better understanding of ultrafast electrical control of exchange interactions in multi-orbital systems, we study a two-orbital Hubbard model at half filling under the action of a time-periodic electric field. Using…
We build a microscopic model to study the intra- and inter-layer superexchange due to electrons hopping in chromium trihalides ($\mathrm{CrX}_3$, X= Cl, Br, and I). In evaluating the superexchange, we identify the relevant intermediate…
The low temperature properties of double exchange model in triangular lattice are investigated via truncated polynomial expansion method (TPEM), which reduces the computational complexity and enables parallel computation. We found that for…
We study the Holstein-Hubbard model at half filling to explore ordered phases including su- perconductivity (SC), antiferromagnetism (AF), and charge order (CO) in situations where the electron-electron and electron-phonon interactions are…
The effect of the Hubbard interaction among conduction electrons on the double exchange model is investigated in a ferromagnetic metallic phase. Applying iterative perturbation theory to the Hubbard interaction within dynamical mean field…
We study the Holstein-Hubbard model at half filling to explore the ordered phases such as the charge density wave and antiferromagnet. The Coulomb interaction is rewritten in terms of auxiliary fields. By treating the auxiliary fields and…
Orbital modeling of two electron spins confined in a double quantum dot is revisited. We develop an extended Hund Mulliken approach that includes excited orbitals, allowing for a triplet configuration with both electrons residing in a…
We develop a quantum kinetic theory of two-dimensional electron gases in which exchange is treated self-consistently at the Hartree-Fock level and enters as a nonlocal, momentum-dependent field in phase space. By starting from the Coulomb…
We investigate the signature of a complete Coulomb interaction in transport properties of double-orbital nanoscale devices. We analyze the specific effects of Hund exchange and pair hopping terms, calculating in particular stability…
We study the one-dimensional two-orbital Hubbard model with general local interactions including a pair-hopping term. The model might be realized in one-dimensional transition-metal nanowires. Phase diagrams at T=0 are obtained by numerical…
We investigate the Cu $L_3$ edge resonant inelastic x-ray scattering (RIXS) spectra of a quasi-1D antiferromagnet Ca$_2$CuO$_3$. In addition to the magnetic excitations, which are well-described by the two-spinon continuum, we observe two…
Single phase, sol-gel prepared Cu1-xFexO (0<x<0.125) are characterized in terms of structural, electronic and magnetic properties. Using dielectric and magnetic studies we investigate the coupling of electron and spin. The electrical…
We study the effective spin-orbital model derived for the d9 ions in a three-dimensional perovskite lattice, as in KCuF_3, where at each site the doubly degenerate eg orbitals contain a single hole. The model describes the superexchange…
We present a valence transition model for electron- and hole-doped cuprates, within which there occurs a discrete jump in ionicity Cu$^{2+} \to$ Cu$^{1+}$ upon doping, at or near optimal doping in the electron-doped compounds and at the…
We investigate the half-filled two-orbital Hubbard model with the crystalline electric field using dynamical mean-field theory combined with the continuous-time quantum Monte Carlo simulations. We systematically study how the interplay of…
We study ground state properties of the double-exchange model on triangle chain in the classical limit on $t_{2g}$ spins. The ground state is determined by a competition among the kinetic energy of the $e_g$ electron, the antiferromagnetic…