Chiral spin liquid in a $\mathbb{Z}_3$ Kitaev model

TL;DR

This study investigates a $ ext{Z}_3$ Kitaev model on a honeycomb lattice, providing evidence it hosts a chiral spin liquid with $ ext{U}(1)_{12}$ topological order, characterized by gapped bulk and chiral edge states.

Contribution

The paper demonstrates that a $ ext{Z}_3$ Kitaev model can realize a chiral spin liquid with $ ext{U}(1)_{12}$ topological order using matrix product state simulations and symmetry analysis.

Findings

Evidence of a gapped 2D bulk with topological entanglement entropy matching $ ext{U}(1)_{12}$ order.

Critical behavior on strips with a central charge consistent with chiral edge theory.

Support for chiral spin liquid phase with $ ext{U}(1)_{12}$ topological order in the $ ext{Z}_3$ Kitaev model.

Abstract

We study a $\mathbb{Z}_3$ Kitaev model on the honeycomb lattice with nearest neighbor interactions. Based on matrix product state simulations and symmetry considerations, we find evidence that, with ferromagnetic isotropic couplings, the model realizes a chiral spin liquid, characterized by a possible $\mathrm{U}(1)_{12}$ chiral topological order. This is supported by simulations on both cylinder and strip geometries. On infinitely long cylinders with various widths, scaling analysis of entanglement entropy and maximal correlation length suggests that the model has a gapped 2D bulk. The topological entanglement entropy is extracted and found to be in agreement with the $\mathrm{U}(1)_{12}$ topological order. On infinitely long strips with moderate widths, we find the model is critical with a central charge consistent with the chiral edge theory of the $\mathrm{U}(1)_{12}$ topological phase. We conclude by discussing several open questions.