%0 Journal Article
%T Magnetic excitation spectrum of Na2IrO3 probed with resonant inelastic x-ray scattering
%A H. Gretarsson
%A J. P. Clancy
%A Yogesh Singh
%A P. Gegenwart
%A J. P. Hill
%A Jungho Kim
%A M. H. Upton
%A A. H. Said
%A D. Casa
%A T. Gog
%A Young-June Kim
%J Physics
%D 2013
%I arXiv
%R 10.1103/PhysRevB.87.220407
%X The low energy excitations in Na2IrO3 have been investigated using resonant inelastic x-ray scattering (RIXS). A magnetic excitation branch can be resolved, whose dispersion reaches a maximum energy of about 35 meV at the \Gamma-point. The momentum dependence of the excitation energy is much larger along the \Gamma-X direction compared to that along the \Gamma-Y direction. The observed dispersion relation is consistent with a recent theoretical prediction based on Heisenberg-Kitaev model. At high temperatures, we find large contributions from lattice vibrational modes to our RIXS spectra, suggesting that a strong electron-lattice coupling is present in Na2IrO3.
%U http://arxiv.org/abs/1304.4484v1