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arXiv · 2003.04835

Dynamics of a two-dimensional quantum spin-orbital liquid: spectroscopic signatures of fermionic magnons

Willian M. H. Natori·Johannes Knolle
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Abstract

We provide an exact study of dynamical correlations for the quantum spin-orbital liquid phases of an SU(2)-symmetric Kitaev honeycomb lattice model. We show that the spin dynamics in this Kugel-Khomskii type model is exactly the density-density correlation function of S=1 fermionic magnons, which could be probed in resonant inelastic x-ray scattering experiments. We predict the characteristic signatures of spin-orbital fractionalization in inelastic scattering experiments and compare them to the ones of the spin-anisotropic Kitaev honeycomb spin liquid. In particular, the resonant inelastic x-ray scattering response shows a characteristic momentum dependence directly related to the dispersion of fermionic excitations. The neutron scattering cross section displays a mixed response of fermionic magnons as well as spin-orbital excitations. The latter has a bandwidth of broad excitations and a vison gap that is three times larger than that of the spin-1/2 Kitaev model.

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Willian M. H. Natori, Johannes Knolle. 2020-03-10. Dynamics of a two-dimensional quantum spin-orbital liquid: spectroscopic signatures of fermionic magnons. https://doi.org/10.1103/physrevlett.125.067201

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