RIXS observation of bond-directional nearest-neighbor excitations in the Kitaev material Na${}_2$IrO${}_3$

M. Magnaterra, K. Hopfer, Ch. J. Sahle +13

Spin-orbit coupling locks spin direction and spatial orientation and generates, in semi-classical magnets, a local spin easy-axis and associated ordering. Quantum spin-1/2's defy t…