Dynamical Response of Classical Spin Liquid in Spin-Orbit Magnets with Strong Off-Diagonal Exchange

Spin liquid state emerging in strongly interacting spin systems has been a highly sought after field of study. These materials retain their magnetic disorder even at zero temperatures. While spin liquid state in conventional cooperative paramagnets emerges due to geometrical frustration, in the case of Kitaev-type models it originates from highly anisotropic exchange interactions [1]. Microscopically, such anisotropic interaction is a direct result of strong spin-orbit coupling [2]. Recently, a new type of classical spin liquid has been proposed on honeycomb lattice, that is driven by large nearest-neighbor off-diagonal exchange interaction Γ [3]. We employ Monte Carlo simulations and Landau-Lifshitz dynamics to evaluate dynamical spin structure factor and study the excitations in this new classical liquid phase. Temperature evolution of structure factor and wave vector dependance of the spectral energy mode distribution is analyzed for pure Γ-model for both antiferromagnetic and ferromagnetic couplings. [1] A. Kitaev, Ann. Phys. 321, 2 (2005). [2] G. Jackeli and G. Khaliullin, Phys. Rev. Lett. 102, 017205 (2009). [3] I. Rousochatzakis and N. B. Perkins Phys. Rev. Lett. 118, 147204 (2017).