Coherence and decoherence in the Harper-Hofstadter model

We quantum simulated the 2D Harper-Hofstadter (HH) lattice model in a highly elongated tube geometry—three sites in circumference—using an atomic Bose-Einstein condensate. In addition to the usual transverse (out-of-plane) magnetic flux, piercing the surface of the tube, we threaded a longitudinal flux ΦL down the axis of the tube. This geometry evokes an Aharonov-Bohm interferometer, where noise in ΦL would readily decohere the interference...