Beecroft Building
Abstract
Ultracold atoms loaded into higher Bloch bands provide an elegant setting for realizing many-body quantum states that spontaneously break time-reversal symmetry through the formation of chiral orbital order. The applicability of this strategy remains nonetheless limited due to the finite lifetime of atoms in high-energy bands. Here, we introduce an alternative strategy, which consists in preparing bosonic atoms in the low-energy orbitals of a square plaquette pierced by a pi-flux (half a magnetic-flux quantum). This setting is shown to be formally equivalent to a bosonic gas loaded into p-orbitals, and we discuss its physical properties both in the weakly and strongly interacting regimes. Specifically, by considering extended lattices formed by assembling these 'pi-flux plaquette' building blocks, we demonstrate the emergence of a chiral superfluid vortex lattice, exhibiting a long-lived gapped collective mode. We also discuss how topological superfluids and chiral Mott insulators can be realized in this novel framework.
This research work, which is still in progress, will be presented in a pedagogical manner, accessible to non-specialists and graduate students.