The algebraic spin liquid in the SU(6) Heisenberg model on the kagome lattice

Abstract: We explore the Dirac spin liquid (DSL) as a candidate for the ground state of the Mott insulating phase of fermions with six flavors on the Kagome lattice, particularly focusing on realizations using $^{173}$Yb atoms in optical lattices. Using mean-field theory and variational Monte Carlo (VMC) simulations, we confirm the stability of the DSL against local perturbations of the Dirac spin liquid ansatz within a 12-site unit cell and against small second-nearest neighbor and ring exchange interactions. To characterize the DSL, we calculate the static and dynamic structure factor of the Gutzwiller projected wavefunction and compare it with mean-field calculations. The static structure factor shows triangular-shaped plateaus around the $K$ points in the extended Brillouin zone, with small peaks at the corners of these plateaus. The dynamical structure factor consists of a gapless continuum of fractionalized excitations. Our study also presents several complementary results, including bounds for the ground state energy, methods for calculating three-site ring exchange expectations in the projective mean field, the boundary of ferromagnetic states, and the non-topological nature of flat bands in the DSL band structure.