Title:

Simulation of gauge theories on optical lattices II - Quantum magnetism and emerging dynamical gauge fields

Speaker:

Gergely Szirmai, Institute for Solid State Physics and Optics, Wigner Research Centre for Physics

Abstract:

In this talk we discuss the dynamics of strongly interacting ultracold fermions on 2-dimensional optical lattices at extremely low temperatures and at a filling of one fermion per site. Close to the ground state multiply occupied states are energetically forbidden and the fermions realize a Mott state with frozen charge dynamics. The only degrees of freedom are the spin degrees, and the system realizes an antiferromagnet due to the superexchange interaction. Specifically, we describe the spin dynamics of the antiferromagnetic Mott insulator ground state of high spin fermions on a 2-dimensional hexagonal lattice. It was pointed out that such multicomponent systems can realize states without breaking the spin rotation symmetry when the number of components is large enough. The low energy fluctuations on top of these so called spin liquid states are described by various gauge theories whose character depend on the symmetries of the mean-field solution. Therefore high spin, ultracold, fermionic alkaline earth metal atoms loaded into optical lattices can serve as simulators of quantum gauge theories.