English

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

Strongly Correlated Electrons 2020-08-07 v3

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.

Keywords

Cite

@article{arxiv.2003.04835,
  title  = {Dynamics of a two-dimensional quantum spin-orbital liquid: spectroscopic signatures of fermionic magnons},
  author = {Willian M. H. Natori and Johannes Knolle},
  journal= {arXiv preprint arXiv:2003.04835},
  year   = {2020}
}

Comments

6 pages, 2 figures, new version with Supplementary Material