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arXiv · 1304.4484

Magnetic excitation spectrum of Na2IrO3 probed with resonant inelastic x-ray scattering

H. Gretarsson·J. P. Clancy·Yogesh Singh·P. Gegenwart·J. P. Hill·Jungho Kim·M. H. Upton·A. H. Said·D. Casa·T. Gog·Young-June Kim
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Abstract

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.

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H. Gretarsson, J. P. Clancy, Yogesh Singh, P. Gegenwart, J. P. Hill, Jungho Kim, M. H. Upton, A. H. Said, D. Casa, T. Gog, Young-June Kim. 2013-04-16. Magnetic excitation spectrum of Na2IrO3 probed with resonant inelastic x-ray scattering. https://doi.org/10.1103/physrevb.87.220407

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