Floquet engineering of a dynamical Z2 lattice gauge field with ultracold atoms

Gauge field theory is a fundamental concept in modern physics,attracting many theoretical and experimental efforts towards its simulation.In this paper we propose that a simple model,in which fermions coupled to a dynamical lattice gauge field,can be engineered via the Floquet approach.The model possesses both an independent Maxwell term and local Z_(2) gauge symmetry.Our proposal relies on a species-dependent optical lattice,and can be achieved in one,two or three dimensions.By a unitary transformation,this model can be mapped into a non-interacting composite fermion system with fluctuating background charge.With the help of this composite fermion picture,two characteristic observations are predicted.One is radio-frequency spectroscopy,which exhibits no dispersion in all parameter regimes.The second is dynamical localization,which depends on the structure of the initial states.