Prof. Karlo Penc (Research Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungary)
"Spin liquid phases in the SU(4) and SU(3) Heisenberg model on the honeycomb lattice"

 SU(N) Heisenberg model is the effective model of Mott insulators with N degrees of freedom per site, when the interaction is highly symmetrical. Such a situation may happen for spin-orbital systems and for ultracold alkaline-earth atoms in optical lattices. Using a combination of analytical and numerical methods, we studied the zero temperature properties of the model on honeycomb lattice for different values of N. In the seminar, I will present our recent findings for the spin-orbital liquid in the SU(4) Heisenberg model on the honeycomb lattice, with algebraic decay of correlations. Furthermore, for the SU(3) case, I will discuss the competition between ordered and plaquette states.