From a quasimolecular band insulator to a relativistic Mott insulator in $t_{2g}^5$ systems with a honeycomb lattice structure

Beom Hyun Kim, Tomonori Shirakawa, Seiji Yunoki

The $t_{2g}$ orbitals of an edge-shared transition-metal oxide with a honeycomb lattice structure form dispersionless electronic bands when only hopping mediated by the edge-sharin…