Abstract
The recent discovery that resonant inelastic x-ray scattering can probe single-magnon (SM) dispersions in transition metal (TM) oxides when the x-ray energy is tuned to the TM edge has put this technique on a par with inelastic neutron scattering. It is generally presumed that selection rules forbid SM scattering at oxygen (O) edges. However, based on a symmetry analysis and exact diagonalization study, we show that SM scattering at O edges becomes allowed when (i) spin-orbit coupling is present in the TM shell and (ii) inversion symmetry at the O site is broken. For cuprates the resulting SM amplitude is very weak, but in iridates both prerequisites can amply be fulfilled.
- Received 7 April 2014
- Revised 7 July 2015
DOI:https://doi.org/10.1103/PhysRevB.92.081105
©2015 American Physical Society