Final Activity Report Summary - BEC FLOW (Instability of superfluid flow in dilute Bose-Einstein condensates) We have demonstrated the existence of a drag force due to quantum fluctuations in a superfluid. This has many important consequences. In particular, it brings us a step closer towards developing a feasible theory to explain observed instability in superfluids, an issue that scientists have been wrestling with since the 1940s. Showing that quantum fluctuations have such a drag effect also has direct bearing on the conception and design of applications, such as the atom laser, where precision in predicting superfluid behaviour is vital. We also explored the mixtures of superfluids, which current experiments are beginning to explore.
