One of the goals of FLEET is to develop transistor technology using superfluid circuits. In collaboration with the ARC Centre of Excellence for Engineered Quantum Systems, we experimentally realize a highly-tunable superfluid oscillator circuit in a quantum gas of ultracold atoms, and develop and verify a simple lumped-element description of this circuit. At low oscillator currents, we demonstrate that the circuit is accurately described as a Helmholtz resonator, a fundamental element of acoustic circuits. At larger currents, the breakdown of the Helmholtz regime is heralded by a turbulent shedding of vortices and density waves. Although a simple phase-slip model offers qualitative insights into the circuit’s resistive behavior, our results indicate deviations from the phase-slip model. A full understanding of the dissipation in superfluid circuits will thus require the development of empirical models of the turbulent dynamics in this system, as have been developed for classical acoustic systems. arXiv:1903.04086
About the speaker
Dr Matt Reeves is a postdoctoral researcher fellow working with Matthew Davis at the University of Queensland within FLEET’s research theme 3.
Matt is currently theoretically investigating how steady forcing and driving can be exploited to engineer novel, emergent, non-equilibrium states of superfluidity. Matt completed his PhD in 2016 at the University of Otago, where he researched fundamental properties of turbulence in quantum and classical fluids.