Three-dimensional chiral spin liquids in the Kitaev model on a hypernonagon lattice

Chiral spin liquids (CSLs) are exotic quantum states without magnetic order but with broken time-reversal symmetry. Recently, the ground-state and finite-temperature (T) behaviors of CSLs have been studied for the Kitaev models [1] on two and three-dimensional (3D) lattice geometries [2-4]. In this talk, we will present a comprehensive study of the ground state and thermodynamic properties of the Kitaev model on the 3D hypernonagon lattice, which has previsously been explored in the limit of anisotropic interactions [4]. Our numerical simulations employ quantum Monte Carlo technique, which in combination with the Chebyshev polynomial expansion [5], allows us to study systems of up to 2600 spins. We find evidence for a first-order phase transition in the isotropic interactions case similar to the anitostopic limits, but into a different type of CSL ground state. We also present the ground-state phase diagram obtained by variational calculations.
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[3] J. Nasu and Y. Motome, Phys. Rev. Lett. 115, 087203 (2015).
[4] Y. Kato, Y. Kamiya, J. Nasu, and Y. Motome, Phys. Rev. B 96, 174409 (2017).
[5] P. A. Mishchenko, Y. Kato, and Y. Motome, Phys. Rev. B 96, 125124 (2017).