Multiple Dirac Spin-Orbital Liquids in SU(4) Heisenberg Antiferromagnets on the Honeycomb Lattice

Abstract: We study the strong coupling model of $d^1$ transition metal tri-halides in the large spin-orbit coupled limit. By considering ab-initio-calculation-inspired hierarchy of hopping pathways of these compounds, SU(4) symmetry is found to emerge at multiple points in the parameter space of the hopping parameters. The resultant Dirac spin-orbital liquids, within the parton mean field description, are distinct. The calculated dynamical structure factor fingerprints this distinctive nature, giving rise to observable effects. This opens up a playground for SU(4) Dirac Spin-Orbital liquid in $d^1$ Honeycomb lattice systems.