Determining Kitaev interaction in spin-S honeycomb Mott insulators
ORAL
Abstract
The Kitaev interaction in a honeycomb lattice with higher-spin S has been one of the central attractions, as it may offer quantum spin liquids. A microscopic theory showed that when the Hund's coupling at the transition metal generates S>1/2, the spin-orbit coupling at the heavy ligands provides a route to the Kitaev interaction. However, there have been debates over its strength compared to other symmetry-allowed interactions. Investigating the symmetry of the Hamiltonian for general S, we show the magnon energies at two momentum points related by a broken mirror symmetry reflect the Kitaev interaction when a magnetic field is in the mirror plane. Applying the symmetry analysis to CrI3 with S=3/2 together with the available angle-dependent ferromagnetic resonance data, we estimate the Kitaev interaction out of the full Hamiltonian and find that it is sub-dominant. Our theory can be tested by inelastic neutron scattering on candidate materials under the proposed magnetic field direction, which will advance the search for general S Kitaev materials.
*This work was supported by the Natural Sciences and Engineering Research Council of Canada and the Canada Research Chairs Program. HYK thanks Aspen Center for Physics supported by National Science Foundation grant PHY-1607611, where a part of the work was performed. This research was enabled in part by support provided by Sharcnet and Compute Canada. Computations were performed on the GPC and Niagara supercomputers at the SciNet HPC Consortium. SciNet is funded by: the Canada Foundation for Innovation under the auspices of Compute Canada; the Government of Ontario; Ontario Research Fund - Research Excellence; and the University of Toronto.
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Publication:Jiefu Cen and Hae-Young Kee, Determining Kitaev interaction in spin-S honeycomb Mott insulators, submitted for review. arXiv:2208.13807
