Spin structure factors of chiral quantum spin liquids on the kagome lattice

TL;DR

This paper computes dynamical spin structure factors for chiral spin liquids on the kagome lattice, revealing signatures of time-reversal symmetry breaking and unique spectral features using Schwinger-boson mean-field theory.

Contribution

It introduces a detailed calculation of dynamical structure factors for chiral spin liquids, highlighting symmetry-breaking signatures and spectral characteristics.

Findings

Dynamical structure factors show time-reversal symmetry breaking signatures.

Loss of momentum inversion and six-fold rotation symmetries in spectra.

Identification of a flat onset of the two-spinon continuum in the cuboc1 state.

Abstract

We calculate dynamical spin structure factors for gapped chiral spin liquid states in the spin-1/2 Heisenberg antiferromagnet on the kagome lattice using Schwinger-boson mean-field theory. In contrast to static (equal-time) structure factors, the dynamical structure factor shows clear signatures of time-reversal symmetry breaking for chiral spin liquid states. In particular, momentum inversion $\bm{k} \to -\bm{k}$ symmetry as well as the six-fold rotation symmetry around the $\Gamma$-point are lost. We highlight other interesting features, such as a relatively flat onset of the two-spinon continuum for the \emph{cuboc1} state. Our work is based on the projective symmetry group classification of time-reversal symmetry breaking Schwinger-boson mean-field states by Messio, Lhuillier, and Misguich.