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arXiv · 1402.2654

Topological and magnetic phases with strong spin-orbit coupling on the hyperhoneycomb lattice

Eric Kin-Ho Lee·Subhro Bhattacharjee·Kyusung Hwang·Heung-Sik Kim·Hosub Jin·Yong Baek Kim
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Abstract

We study the general phase diagram of correlated electrons for iridium-based (Ir) compounds on the hyperhoneycomb lattice---a crystal structure where the Ir$^{4+}$ ions form a three-dimensional network with three-fold coordination recently realized in the $\beta$-Li${}_{2}$IrO${}_{3}$ compound. Using a combination of microscopic derivations, symmetry analysis, and density functional calculations, we determine the general model for the electrons occupying the $j_{\text{eff}}=1/2$ orbitals at the Ir$^{4+}$ sites. In the non-interacting limit, we find that this model allows for both topological and trivial electronic band insulators along with metallic states. The effect of Hubbard-type electron-electron repulsion on the above electronic structure in stabilizing $\mathbf{q}=\mathbf{0}$ magnetic order reveals a phase diagram with continuous phase transition between a topological band insulator and a Neel ordered magnetic insulator.

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Eric Kin-Ho Lee, Subhro Bhattacharjee, Kyusung Hwang, Heung-Sik Kim, Hosub Jin, Yong Baek Kim. 2014-02-11. Topological and magnetic phases with strong spin-orbit coupling on the hyperhoneycomb lattice. https://doi.org/10.1103/physrevb.89.205132

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