Kitaev Spin Liquid in 3d Transition Metal Compounds

We have proposed that 3d honeycomb cobaltates are very promising candidates to realize the Kitaev spin liquid state, thanks to the easy tunability of the exchange Hamiltonian in favor of Kitaev interaction [1-3]. The key parameters that have major impacts on the exchange constants, such as the charge-transfer gap and the trigonal crystal field, are discussed. Several materials are considered as examples to show the proximity to the Kitaev spin liquid phase, and can be driven into it by lattice engineering. Our theoretical predications suggest that cobaltates offer the most promising search area for Kitaev model physics.