Probing Nagaoka ferromagnetism in optical superlattices

In 1966, Nagaoka predicted that interaction-induced ferromagnetism occurs~in lattices with specific geometry when there is one fewer electron than in the half-filled system. Here, we describe a controllable method for observing Nagaoka Ferromagnetism in isolated plaquettes (four lattice sites arranged in a square) created using~optical superlattices. We next discuss the weakly coupled plaquettes and suggest several approaches for creating systems exhibiting itinerant ferromagnetism.