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arXiv · 1903.00011

Microscopic mechanism for higher-spin Kitaev model

P. Peter Stavropoulos·D. Pereira·Hae-Young Kee
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Abstract

The spin S=$\frac{1}{2}$ Kitaev honeycomb model has attracted significant attention, since emerging candidate materials have provided a playground to test non-Abelian anyons. The Kitaev model with higher spins has also been theoretically studied, as it may offer another path to a quantum spin liquid. However, a microscopic route to achieve higher spin Kitaev models in solid state materials has not been rigorously derived. Here we present a theory of the spin S=1 Kitaev interaction in two-dimensional edge-shared octahedral systems. Essential ingredients are strong spin-orbit coupling in anions and strong Hund's coupling in transition metal cations. The S=1 Kitaev and ferromagnetic Heisenberg interactions are generated from superexchange paths. Taking into account the antiferromagnetic Heisenberg term from direct-exchange paths, the Kitaev interaction dominates the physics of S=1 system. Using exact diagonalization technique, we show a finite regime of S=1 spin liquid in the presence of the Heisenberg interaction. Candidate materials are proposed, and generalization to higher spins is discussed.

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P. Peter Stavropoulos, D. Pereira, Hae-Young Kee. 2019-02-28. Microscopic mechanism for higher-spin Kitaev model. https://doi.org/10.1103/physrevlett.123.037203

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