Related papers: Metal-insulator transitions in pyrochlore oxides
There are reasons to believe that the ground state of the magnetic rare earth pyrochlore Yb$_2$Ti$_2$O$_7$ is on the boundary between competing ground states. We have carried out $\mathrm{\textit{ab initio}}$ density functional calculations…
The rare-earth based pyrochlore molybdates involve orbitally degenerate electrons Hund's coupled to local moments. The large Hund's coupling promotes ferromagnetism, the superexchange between the local moments prefers antiferromagnetism,…
Transition metal oxides, in particular, 3d or 4d perovskites have provided diverse emergent physics that originates from the coupling of various degrees of freedom such as spin, lattice, charge, orbital, and also disorder. 5d perovskites…
The notion of strong electronic correlations arose in the context of $d$-metal oxides such as NiO but can be exemplified on systems as simple as the H$_2$ molecule. Here we shed light on correlation effects on B$_6^{2-}$ clusters as found…
We have investigated the structural, electronic, and magnetic properties of the pyrochlore iridates Eu2Ir2O7 and Pr2Ir2O7 using a combination of resonant elastic x-ray scattering, x-ray powder diffraction, and resonant inelastic x-ray…
Using first-principles electronic structure calculations, we have extensively studied the electronic and magnetic properties of alkali sodium superoxide (NaO2) in comparison with that of potassium superoxide (KO2) both at high and low…
Cd2Os2O7 crystallizes in the pyrochlore structure and undergoes a metal-insulator transition (MIT) near 226 K. We have characterized the MIT in Cd2Os2O7 using X-ray diffraction, resistivity at ambient and high pressure, specific heat,…
We study \textit{ab initio} a pyrochlore compound, CsW$_{2}$O$_{6}$, which exhibits a yet unexplained metal-insulator transition. We find that (1) the reported low-$T$ structure is likely inaccurate and the correct structure has a twice…
A major challenge in condensed matter physics is integrating topological phenomena with correlated electron physics to leverage both types of states for next-generation quantum devices. Metal-insulator transitions (MITs) are central to…
The structural, electronic, and optical properties of pyrochlore-type Pb$_{2}$Ir$_{2}$O$_{6}$O'$_{0.55}$, which is a metal without spatial inversion symmetry at room temperature, were investigated. Structural analysis revealed that the…
We report on the structural, magnetic, and electronic properties of two new double-perovskites synthesized under high pressure; Pb2CaOsO6 and Pb2ZnOsO6. Upon cooling below 80 K, Pb2CaOsO6 simultaneously undergoes a metal--insulator…
The possibility of the strong electron-electron interaction driven insulating phase from the metallic phase in two-dimensions has been suggested for clean systems without intentional disorder, but its rigorous demonstration is still…
The layered 5d transition metal oxides like Sr2IrO4 have attracted significant interest recently due to a number of exotic and new phenomena induced by the interplay between the spin-orbit coupling, bandwidth W and on-site Coulomb…
We present a first-principles study of the electronic structure and superconducting parameters of the compounds $A$Os$_2$O$_6$ ($A$ = Na, K, Rb, and Cs) and at ambient and applied hydrostatic pressure. We find that the sensitivity of the…
Pyrochlore oxides are fascinating systems where strong, multi-orbital correlations in concert with geometrical frustration give rise to unanticipated physical properties. The detailed mechanism of the insulator-metal transitions (IMT)…
We investigated the magnetoresistance (MR) effect of the pyrochlore oxide Nd2Ir2O7, which shows a metal-insulator transition at T_MI =33 K. A small positive MR effect was observed in the metallic state above T_MI, while a large negative MR…
The spin-orbit Mott insulator Sr3Ir2O7 provides a fascinating playground to explore insulator-metal transition driven by intertwined charge, spin, and lattice degrees of freedom. Here, we report high pressure electric resistance and…
We report the observation of an unusual behavior of highly extended 5d electrons in Y2Ir2O7 belonging to pyrochlore family of great current interest using high resolution photoemission spectroscopy. The experimental bulk spectra reveal an…
The 5d-transition metal pyrochlore oxide Cd2Re2O7, which was recently suggested to be a prototype of the spin-orbit-coupled metal [Phys. Rev. Lett. 115, 026401 (2015)], exhibits an inversion-symmetry breaking (ISB) transition at 200 K and a…
The pyrochlore lattice is associated with several potential and actual spin liquid phases as a result of its strong geometric frustration. At finite temperature, these can exhibit an unusually broad cross-over regime to a conventional…