First principles calculations on chemically intercalated honeycomb Kitaev materials

Layered honeycomb-lattice with 4d and 5d trainsition metals are being intensively discussed as possible realizations of the Kitaev model where magnetism is dominated by a strong spin-orbit coupling resulting in highly nontrivial physical properties. In this talk, we will discuss the role of inter- and intra-layer chemical intercalation on the electronic and magnetic properties of some representative families from first principles calculations, model considerations and comparison with experiment.

We will present results on (i) the spin-orbit Mott insulator family K_xIr_yO₂ where the potassium content acts as a chemical tuning parameter to control the amount of charge in the Ir-O layers. We will show that in the experimentally unexplored regime that interpolates between triangular and honeycomb structures K_xIr_yO₂ is a candidate to display Kitaev magnetism [1]. (ii) The intercalated compounds H₃LiIr₂O₆ [2], Ag₃LiIr₂O_6. Our study suggests that the magnetic response in these systems is extremely sensitive to both the stoichiometry and the microstructure of the samples and emphasize the importance of a careful treatment of inter-layer atoms for similar systems.

[1] R. D. Johnson, I. Broeders, K. Mehlawat, Y. Li, Yogesh Singh, R. Valentí, and R. Coldea, Phys. Rev. B 100, 214113 (2019).
[2] Ying Li, Stephen M. Winter, and Roser Valentí, Phys. Rev. Lett. 121, 247202 (2018).