Finite temperature dynamics of Kitaev's spin liquid

Kitaev's honeycomb model is drawing considerable attention as a realistic stage of long-sought quantum spin liquid (QSL) phase.
Among the fascinating properties of Kitaev's model, the field-induced chiral spin liquid (CSL) deserves a special attention. The realization of CSL is intensively discussed in alpha-RuCl3, stimulated by the half-integer quantization of thermal Hall conductivity.

In this talk, we will consider the Kitaev's model with three-spin interactions stabilizing the CSL phase. We address the finite-temperature spin dynamics of this phase, by the recently obtained analytical solution of dynamical structure factor [1], built into the classical Monte Carlo simulation.

This scheme makes it possible to access the real-time (frequency) dynamics of this model at arbitrary temperatures. As a result, we found a crossover from the thermal anyon metallic state stabilized at intermediate temperatures to the CSL phase at low temperatures, as clearly indicated by the quasi-resonance peaks in the magnetic structure factor. We also use the same technique to address the local spin dynamics around a vacancy in the system, which captures the presence of fractional zero modes associated with the vacancy.
[1] M. Udagawa, Phys. Rev. B 98, 220404(R) (2018)