相关论文: Superexchange interactions between spin-orbit-coup…
Inelastic neutron scattering measurements have been performed to investigate the spin waves of the quasi-one-dimensional antiferromagnetic ladder compound BaFe$_2$S$_3$, where a superconducting transition was observed under pressure [H.…
Charge transfer is of particular importance in manipulating the interface physics in transition-metal oxide heterostructures. In this work, we have fabricated epitaxial bilayers composed of polar 3d LaMnO3 and nonpolar 5d SrIrO3. Systematic…
Na$_2$IrO$_3$, a honeycomb 5$d^5$ oxide, has been recently identified as a potential realization of the Kitaev spin lattice. The basic feature of this spin model is that for each of the three metal-metal links emerging out of a metal site,…
The electronic and magnetic structure, including the Heisenberg model exchange interaction parameters, was explored for the recently proposed novel cuprate Cu$_2$F$_5$. Using the DFT+U calculation, it is shown that the compound is formed by…
We introduce Bi$_2$CuO$_3$(SO$_4$) as a rare example of a spin-ladder magnet with ferromagnetic interactions on the rungs. Its magnetic response is studied through measurements of heat capacity, temperature-dependent magnetic…
The effects of a spin-orbit interaction on transition-metal ions of (4d)^3- and (5d)^3 -based oxides in which three electrons occupy t_{2g} orbitals are studied. The amplitude of the magnetic moment of d electrons on the 5d and 4d orbitals…
The superexchange theory predicts dominant antiferromagnetic kinetic interaction when the orbitals accommodating magnetic electrons are covalently bonded through diamagnetic bridging atoms/groups. Here we show that explicit consideration of…
By ab initio many-body quantum chemistry calculations, we determine the strength of the symmetric anisotropy in the 5$d^5$ j $\approx$ 1/2 layered material Ba$_2$IrO$_4$. While the calculated anisotropic couplings come out in the range of a…
We derive a spin-orbital Hamiltonian for a triangular lattice of e_g orbital degenerate (Ni^{3+}) transition metal ions interacting via 90 degree superexchange involving (O^{2-}) anions, taking into account the on-site Coulomb interactions…
A new method of computing multipolar exchange interaction in spin-orbit coupled systems is developed using multipolar tensor expansion of the density matrix in LDA+U electronic structure calculation. Within mean-field approximation,…
Iridates abound with interesting magnetic behaviours because of their strong spin-orbit coupling. Sr$_3$NiIrO$_6$ brings together the spin-orbital entanglement of the Ir$^{4+}$ ion with a 3$d$ Ni cation and a one-dimensional crystal…
Using resonant x-ray diffraction, we observe an easy c-axis collinear antiferromagnetic structure for the bilayer Sr$_3$Ir$_2$O$_7$, a significant contrast to the single layer Sr$_2$IrO$_4$ with in-plane canted moments. Based on a…
We calculate Heisenberg-type magnetic exchange interactions for SrMnO$_3$ under isotropic volume expansion using an approach that is based on total energy variations due to infinitesimal spin rotations around a given reference state. Our…
We develop a microscopic theory of multipole interactions and orderings in 5$d^2$ transition metal ion compounds. In a cubic environment, the ground state of 5$d^2$ ions is a non-Kramers $E_g$ doublet, which is nonmagnetic but hosts…
Motivated by experiments on the double perovskites La2ZnIrO6 and La2MgIrO6, we study the magnetism of spin-orbit coupled j=1/2 iridium moments on the three-dimensional, geometrically frustrated, face-centered cubic lattice. The…
We have analyzed the magnetic interactions of a five orbital model for iron superconductors treated both within Hartree-Fock and Heisenberg approximations. We have found that the exchange constants depend non-trivially on the Fe-As-Fe angle…
The exchange interaction between 5d electrons in t$_{2g}$ orbitals is derived in the J-J coupling scheme which is the appropriate basis in the case of strong spin-orbit interaction. From simple calculations, it is found that ferromagnetic…
Specific features of orbital and spin structure of transition metal compounds in the case of the face-sharing MO$_6$ octahedra are analyzed. In this geometry, we consider the form of the spin--orbital Hamiltonian for transition metal ions…
We use ab initio electronic structure calculations within the generalized gradient approximation (GGA+U) to density functional theory (DFT) to determine the microscopic exchange interactions in the series of orthorhombic rare-earth…
Strong correlations, multiple lattice degrees of freedom, and the ease of doping make complex oxides a source of great research interest. Complex oxide heterointerfaces break inversion symmetry and can host a two dimensional carrier gas,…