PIRSA:14050025

Generic Spin Model for Honeycomb Iridates Beyond the Kitaev Limit

Rau, J. (2014). Generic Spin Model for Honeycomb Iridates Beyond the Kitaev Limit. Perimeter Institute. https://pirsa.org/14050025

Rau, Jeffrey. Generic Spin Model for Honeycomb Iridates Beyond the Kitaev Limit. Perimeter Institute, May. 01, 2014, https://pirsa.org/14050025 

          @misc{ pirsa_PIRSA:14050025,
            doi = {10.48660/14050025},
            url = {https://pirsa.org/14050025},
            author = {Rau, Jeffrey},
            keywords = {},
            language = {en},
            title = {Generic Spin Model for Honeycomb Iridates Beyond the Kitaev Limit},
            publisher = {Perimeter Institute},
            year = {2014},
            month = {may},
            note = {PIRSA:14050025 see, \url{https://pirsa.org}}
          }

Jeffrey Rau University of Toronto

DOI 10.48660/14050025
Collection
Talk Type Conference

Abstract

Recently, realizations of Kitaev physics have been sought in the A2IrO3 family of honeycomb iridates, originating from oxygen-mediated exchange through edge-shared octahedra. However, for the J=1/2 Mott insulator in these materials exchange from direct d-orbital overlap is relevant, and it was proposed that a Heisenberg term should be added to the Kitaev model. Here we provide the generic nearest-neighbour spin Hamiltonian when both oxygen-mediated and direct overlap are present, containing a bond dependent off-diagonal exchange in addition to Heisenberg and Kitaev terms. We analyze this complete model using a combination of classical techniques and exact diagonalization. Near the Kitaev limit, we find new magnetic phases, 120 degree and incommensurate spiral order, as well as extended regions of zigzag and stripy order. Possible applications to Na2IrO3 and Li2IrO3 are discussed.