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arXiv · 1501.07582

Phases and phase transitions of a perturbed Kekulé-Kitaev model

Eoin Quinn·Subhro Bhattacharjee·Roderich Moessner
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Abstract

We study the quantum spin liquid phase in a variant of the Kitaev model where the bonds of the honeycomb lattice are distributed in a Kekulé pattern. The system supports gapped and gapless Z_2 quantum spin liquids with interesting differences from the original Kitaev model, the most notable being a gapped Z_2 spin liquid on a Kagome lattice. Perturbing the exactly solvable model with antiferromagnetic Heisenberg perturbations, we find a magnetically ordered phase stabilized by a quantum `order by disorder' mechanism, as well as an exotic continuous phase transition between the topological spin liquid and this magnetically ordered phase. Using a combination of field theory and Monte-Carlo simulations, we find that the transition likely belongs to the 3D-XYxZ_2 universality class.

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Eoin Quinn, Subhro Bhattacharjee, Roderich Moessner. 2015-04-17. Phases and phase transitions of a perturbed Kekulé-Kitaev model. https://doi.org/10.1103/physrevb.91.134419

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