Models and materials for generalized Kitaev magnetism

Abstract The exactly solvable Kitaev model on the honeycomb lattice has recently received enormous attention linked to the hope of achieving novel spin-liquid states with fractionalized Majorana-like excitations. In this review, we analyze the mechanism proposed by Jackeli and Khaliullin to identify Kitaev materials based on spin-orbital dependent bond interactions and provide a comprehensive overview of its implications in real materials. We set the focus on experimental results and current theoretical understanding of planar honeycomb systems (Na 2 IrO 3 , α -Li 2 IrO 3 , and α -RuCl 3 ), three-dimensional Kitaev materials ( β - and γ -Li 2 IrO 3 ), and other potential candidates, completing the review with the list of open questions awaiting new insights.