A Bose-Einstein condensate confined in ring shaped lattices interrupted by a weak link and pierced by an effective magnetic flux defines the atomic counterpart of the superconducting quantum interference device: the atomtronic quantum interference device (AQUID). In this paper, we report on the detection of current states in the system through a self-heterodyne protocol. Following the original proposal of the NIST and Paris groups, the ring-condensate many-body wave function interferes with a reference condensate expanding from the center of the ring. We focus on the rf-AQUID which realizes effective qubit dynamics. Both the Bose-Hubbard and Gross-Pitaevskii dynamics are studied. For the Bose-Hubbard dynamics, we demonstrate that the selfheterodyne protocol can be applied, but higher-order correlations in the evolution of the interfering condensates are measured to readout of the current states of the system. We study how states with macroscopic quantum coherence can be told apart analyzing the noise in the time of flight of the ring condensate.

Context In contrast to marine environments, microplastic pollution in freshwater systems is understudied. Previous research suggests that freshwater macrophytes function as microplastic sinks, which, because they are at the base of food webs, has implications for higher trophic levels. Aim This study compares the ability of freshwater plants with different leaf morphologies to trap downwelling microplastics. Method Microplastics (800–1000 μm polyamide grains) were deposited onto three macrophyte species, namely, Cabomba caroliniana, Egeria densa, and Hygrophila polysperma. Microplastic mass retained was calculated as the percentage of microplastic mass captured by the plant and standardised microplastic retention was calculated as the absolute microplastic mass retained (g) divided by plant dry mass (g). Results The amount of trapped microplastics differed significantly among species, with the highest amount trapped by C. caroliniana (39.3%; 7.91 g g−1), followed by E. densa (28.8%; 5.30 g g−1) and H. polysperma (17.6%; 4.47 g g−1). Conclusion Significant differences in microplastic retention among species may be attributed to variation in leaf morphology. Implications These findings have potential applications in bioremediation and biomonitoring, where freshwater macrophytes could help with the tracking and mitigation of microplastics in the environment.

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