Excitation spectrum of spin-1 Kitaev spin liquids

We study the excitation spectrum of the spin-1 Kitaev model using the symmetric tensor network. By evaluating the virtual order parameters defined on the virtual Hilbert space in the tensor network formalism, we confirm the ground state is in a Z(2) spin-liquid phase. Using the correspondence between the transfer matrix spectrum and low-lying excitations, we find that contrary to the dispersive Majorana excitation in the spin-1/2 case, the isotropic spin-1 Kitaev model has a dispersive bosonic charge excitation. The bottom of the gapped single-particle charge excitations is found at K, K' = (+/- 2 pi/3, +/- 2 pi/3), with a corresponding correlation length of xi approximate to 6.7 unit cells. The lower edge of the two-particle continuum, which is closely related to the dynamical structure factor measured in inelastic neutron scattering experiments, is obtained by extracting the excitations in the vacuum superselection sector in the anyon theory language.

Automated summary

Using the symmetric tensor network, we studied the excitation spectrum of the spin-1 Kitaev model and confirmed the ground state is in a Z(2) spin-liquid phase. Unlike the spin-1/2 case, the isotropic spin-1 Kitaev model exhibits dispersive bosonic charge excitation. The correlation length for the gapped single-particle charge excitation is approximately 6.7 unit cells.