Excitation spectrum of spin-1 Kitaev Spin Liquids

Yu-Hsueh Chen^1*, Jozef Genzor¹, Yong Baek Kim², Ying-Jer Kao^1,3

¹Department of Physics and Center for Theoretical Physics, National Taiwan University, Taipei, Taiwan
²Department of Physics, University of Toronto, Toronto, Ontario, Canada
³Physics Division, National Center for Theoretical Science, National Taiwan University, Taipei, Taiwan

* Presenter:Yu-Hsueh Chen, email:share060206027594@gmail.com

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 $\mathbb{Z}_2$ 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 anyon excitation.Bottom of the gapped single-particle charge excitations are found at $\mathbf{K}, \mathbf{K}'=(\pm2\pi/3, \mp 2\pi/3)$, with a corresponding correlation length of $\xi \approx 6.7$ 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.

Keywords: 􏴶􏱃􏰤􏰨􏰦􏱃􏰧􏰭􏰣􏰂􏰨􏰰􏰂􏱅􏱃􏰂􏰀􏰭Quantum spin liquids, Kitaev model, Tensor Network, Excitation spectrum