相关论文: Spin-orbit entangled j=1/2 moments in Ba$_2$CeIrO$…
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…
Mott insulators with spin-orbit entangled j=1/2 moments host intriguing magnetic properties. The j=1/2 wave function requires cubic symmetry, while a noncubic crystal field mixes j=1/2 and 3/2 character. Spectroscopic studies of $5d^5$…
We report on the cubic double perovskite Ba2MgReO6 containing Re6+ ions with the 5d1 electron configuration. Resistivity, magnetization, and heat capacity measurements using single crystals show that the compound is a Mott insulator with a…
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…
We report the crystal structure, magnetization and neutron scattering measurements on the double perovskite Ba$_2$YOsO$_6$. The $Fm\overline{3}m$ space group is found both at 290~K and 3.5~K with cell constants $a_0 = 8.3541(4)$~{\AA} and…
We present a powder inelastic neutron scattering study of magnetic excitations in Ba$_2$FeReO$_6$, a member of the double perovskite family of materials which exhibit half-metallic behavior and high Curie temperatures. We find clear…
Dynamical correlations of Jeff = 1/2 isospins in the paramagnetic state of spin-orbital Mott insu- lator Sr2IrO4 was revealed by resonant magnetic x-ray diffuse scattering. We found two-dimensional antiferromagnetic fluctuation with a large…
We construct and analyze a microscopic model for insulating rock salt ordered double perovskites, with the chemical formula A$_2$BB'O$_6$, where the B' atom has a 4d$^1$ or 5d$^1$ electronic configuration and forms a face centered cubic…
The Heisenberg-Kitaev (HK) model on the triangular lattice is conceptually interesting for its interplay of geometric and exchange frustration. HK models are also thought to capture the essential physics of the spin-orbital entanglement in…
We study magnetism on the fcc lattice with tetragonal distortions, with general exotic directional magnetic interactions allowed by symmetry. We consider two models, corresponding to a uniform tetragonal distortion, or a two-sublattice…
The double perovskite \bnoo with heptavalent Os ($d^1$) is observed to remain in the ideal cubic structure ({\it i.e.} without orbital ordering) despite single occupation of the $t_{2g}$ orbitals, even in the ferromagnetically ordered phase…
The electronic and magnetic properties of monoclinic double perovskite Sr$_2$CeIrO$_6$ were examined based on both experiments and first-principles density functional theory calculations. From the calculations we conclude that…
The spin-1/2 square-lattice Heisenberg model is predicted to have a quantum disordered ground state when magnetic frustration is maximized by competing nearest-neighbor $J_1$ and next-nearest-neighbor $J_2$ interactions ($J_2/J_1 \approx…
The magnetic structure of Ca$_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…
We develop anisotropic pseudo-spin antiferromagnetic Heisenberg models for monoclinically distorted double perovskites. We focus on these A$_2$BB'O$_6$ materials that have magnetic moments on the 4d or 5d transition metal B' ions, which…
The Jeff=1/2 state is manifested in systems with large cubic crystal field splitting and spin-orbit coupling that are comparable to the on-site Coulomb interaction, U. 5d transition metal oxides host parameters in this regime and strong…
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…
Frustrated transition metal compounds in which spin-orbit coupling (SOC) and electron correlation work together have attracted much attention recently. In the case of 5$d$ transition metals, where SOC is large, $j_\text{eff}=1/2$ bands near…
We have performed inelastic neutron scattering (INS) experiments to investigate the magnetic excitations in the weakly distorted face-centered-cubic (fcc) iridate double perovskites La$_2$ZnIrO$_6$ and La$_2$MgIrO$_6$, which are…
The interplay between spin-orbit coupling, anisotropic magnetic interaction, frustration-induced quantum fluctuations and spin correlations can lead to novel quantum states with exotic excitations in rare-earth-based quantum magnets.…