Rarefaction waves and channel turbulence in a superfluid dam-breaking experiment

The development of ultracold atomic tabletop experiments has given unprecedented access to investigations into superfluid hydrodynamics. A canonical problem of hydrodynamics is the dam-break problem, where a channel is separated into a full and an empty (or partially filled) section, and the separating barrier is abruptly removed. In our previous work, we have experimentally realized the development of dispersive shock waves in the presence of superfluid-superfluid counterflow in a quasi-1D channel, as well as viscous shock waves preceding a driven optical piston. Here, we expand this work by investigating the dam-breaking problem in an elongated Rb-87 Bose-Einstein condensate to study rarefaction waves with both "dry bed" and "wet bed" initial conditions. This poster will describe our experimental method using a 1D sweeping repulsive potential and our experimental results, indicating rich turbulent regions when even a small number of atoms have been introduced, e.g. the "wet bed" scenario. This work provides a new pathway towards the study of superfluid channel turbulence, an outstanding problem in superfluid hydrodynamics.