@article{discovery1421842, note = {Copyright {\copyright} 2014 American Physical Society.}, journal = {Physical Review Letters}, number = {2}, title = {Resonant X-Ray Scattering and the Jeff=1/2 Electronic Ground State in Iridate Perovskites}, year = {2014}, month = {January}, volume = {112}, author = {Moretti Sala, M and Boseggia, S and McMorrow, DF and Monaco, G}, url = {http://dx.doi.org/10.1103/PhysRevLett.112.026403}, abstract = {The resonant x-ray scattering (magnetic elastic, RXMS, and inelastic, RIXS) of Ir4+ at the L2,3 edges relevant to spin-orbit Mott insulators An+1IrnO3n+1 (A=Sr, Ba, etc.) are calculated using a single-ion model which treats the spin-orbit and tetragonal crystal-field terms on an equal footing. Both RXMS and RIXS in the spin-flip channel are found to display a nontrivial dependence on the direction of the magnetic moment, {\ensuremath{\mu}}. Crucially, we show that for {\ensuremath{\mu}} in the ab plane, RXMS in the cross-polarized channel at the L2 edge is zero irrespective of the tetragonal crystal field; spin-flip RIXS, relevant to measurements of magnons, behaves reciprocally, being zero at L2 when {\ensuremath{\mu}} is perpendicular to the ab plane. Our results have important implications for the assignment of a jeff=1/2 ground state on the basis of resonant x-ray experiments.}, issn = {0031-9007} }