Proposed realization of itinerant ferromagnetism in optical lattices

Abstract

We propose a scheme to realize the itinerant ferromagnetism of two-component cold fermionic atoms in the p-orbital bands in optical lattices. The band flatness in the two-dimensional honeycomb lattice dramatically amplifies the interaction effect, driving the ferromagnetic transition even with a relatively weak repulsive interaction. This scheme has the advantage that the stability of the system can be maintained without causing decay to the molecular state as one approaches the Feshbach resonance from the side with the positive scattering length. Experimental signatures and detections are also discussed. ©2010 The American Physical Society.