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arXiv · 1409.7820

Global phase diagram, possible chiral spin liquid and topological superconductivity in the triangular Kitaev-Heisenberg model

Kai Li·Shun-Li Yu·Jian-Xin Li
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Abstract

The possible ground states of the undoped and doped Kitaev-Heisenberg model on a triangular lattice are studied. For the undoped system, a combination of the numerical exact diagonalization calculation and the four-sublattice transformation analysis suggests one possible exotic phase and four magnetically ordered phases including a collinear stripe pattern and a noncollinear spiral pattern in the global phase diagram. The exotic phase near the antiferromagnetic (AF) Kitaev point is further investigated by using the Schwinger-fermion mean-field method, and we obtain an energetically favorable $Z_2$ chiral spin liquid with a Chern number $\pm2$ as a promising candidate. At finite doping, we find that the AF Heisenberg coupling supports an $s$-wave or a $d_{x^2-y^2}+id_{xy}$-wave superconductivity (SC), while the AF and the ferromagnetic Kitaev interactions favor a $d_{x^2-y^2}+id_{xy}$-wave SC and a time-reversal invariant topological $p$-wave SC, respectively. Possible experimental realizations and related candidate materials are also discussed.

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Kai Li, Shun-Li Yu, Jian-Xin Li. 2014-09-27. Global phase diagram, possible chiral spin liquid and topological superconductivity in the triangular Kitaev-Heisenberg model. https://doi.org/10.1088/1367-2630/17/4/043032

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