Almost pure <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>J</mml:mi><mml:mtext>eff</mml:mtext></mml:msub><mml:mo>=</mml:mo><mml:mfrac><mml:mn>1</mml:mn><mml:mn>2</mml:mn></mml:mfrac></mml:math> Mott state of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>In</mml:mi><mml:msub><mml:mrow/><mml:mn>2</mml:mn></mml:msub><mml:mi>Ir</mml:mi><mml:msub><mml:mrow/><mml:mn>2</mml:mn></mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:msub><mml:mrow/><mml:mn>7</mml:mn></mml:msub></mml:math> in the limit of reduced intersite hopping
Aleksandra Krajewska, T. Takayama, Robert E. Dinnebier, A. N. Yaresko, Kenji Ishii, Masahiko Isobe, H. Takagi
Abstract
The pyrochlore iridates ${A}_{2}$Ir${}_{2}$O${}_{7}$ are expected to host novel electronic phases due to the interplay of spin-orbit coupling and correlation on a frustrated lattice. Their properties and orbital character are reported to vary as a function of the distortion of IrO${}_{6}$ octahedra, which is scaled by the $A$ cation radius. Here, the authors report a new pyrochlore iridate In${}_{2}$Ir${}_{2}$O${}_{7}$ at the small $A$ cation and large distortion limit. By means of resonant inelastic x-ray scattering and band calculations they show that the orbital character of pyrochlore iridates largely depends on Ir-O-Ir intersite hopping rather than the local distortions. Furthermore, the In-O bond covalency in In${}_{2}$Ir${}_{2}$O${}_{7}$ suppresses this intersite hopping, generating a nearly pure ${J}_{\text{eff}}$=\textonehalf{} state, in contrast to other pyrochlore iridates.