Pietro Smaniotto: Superfluid helium vortex flow - RQI Circuit Nottingham 2023

Title: Superfluid helium vortex flow a simulator for QFT in rotating curved spacetimes
Abstract: Gravity simulators offer the prospect of emulating quantum field dynamics on curved spacetime in tabletop experiments. Our research focuses on gravity simulations of curved spacetime scenarios such as rotating black holes on superfluid helium interfaces. Our experiment offers an alternative platform to two-dimensional ultra-cold atom systems, polaritons and other quantum fluids. Specifically, our set-up, based on a large draining vortex flow in superfluid helium, covers a distinct parameter space, resulting in a controlled, finite temperature quantum field theory simulator equipped with a simultaneous readout of micrometre fluctuations of the superfluid interface in time and space. We exploit intricate interactions between interface waves and the underlying vortex flow to show that our approach results in a compact, central vortex structure with significant circulation, overcoming current limitations in other systems. We detect bound states in some wave patterns, highlighting their spatial confinement due to the irrotational flow created by the central vortex. Additionally, we identify signatures of black hole ringdown in specific vortex configurations, opening avenues to study black hole phenomena using superfluid helium.