Springer Transport and Turbulence in Quasi-Uniform and Versatile Bose-Einstein Condensates (Springer Theses)

Advancing the experimental study of superfluids relies on increasingly sophisticated techniques. We develop and demonstrate the loading of Bose-Einstein condensates (BECs) into nearly arbitrary trapping potentials, with a resolution improved by a factor of seven when compared to reported systems. These advanced control techniques have since been adopted by several cold atoms labs around the world. How this BEC system was used to study 2D superfluid dynamics is described. In particular, negative temperature vortex states in a two-dimensional quantum fluid were observed. These states were first predicted by Lars Onsager 70 years ago and have significance to 2D turbulence in quantum and classical fluids, long-range interacting systems, and defect dynamics in high-energy physics. These experiments have established dilute-gas BECs as the prototypical system for the experimental study of point vortices and their nonequilibrium dynamics.  We also developed a new approach to superfluid circuitry based on classical acoustic circuits, demonstrating its conceptual and quantitative superiority over previous lumped-element models. This has established foundational principles of superfluid circuitry that will impact the design of future transport experiments and new generation quantum devices, such as atomtronics circuits and superfluid sensors. From the Back Cover Advancing the experimental study of superfluids relies on increasingly sophisticated techniques. This work develops and demonstrates the loading of Bose-Einstein condensates (BECs) into nearly arbitrary trapping potentials, with a resolution improved by a factor of seven when compared to reported systems. These advanced control techniques have now been adopted by several cold atoms labs around the world.   The book describes how this BEC system was used to study 2D superfluid dynamic. In particular, negative temperature vortex states in a two-dimensional quantum fluid were observed. These states were first predicted by Lars Onsager 70 years ago and have significance to 2D turbulence in quantum and classical fluids, long-range interacting systems, and defect dynamics in high-energy physics. These experiments have established dilute-gas BECs as the prototypical system for the experimental study of point vortices and their nonequilibrium dynamics.    Also presented is a new approach to superfluid circuitry based on classical acoustic circuits, whose conceptual and quantitative superiority over previous lumped-element models is demonstrated. This approach has established foundational principles of superfluid circuitry that will impact the design of future transport experiments and new generation quantum devices, such as atomtronics circuits and superfluid sensors. About the Author Guillaume Gauthier received his B.Eng from McMaster University in 2014 and D.Phil. degree in 2019 from the University of Queensland. He is currently a research academic at in the cold atom group at the University of Queensland where he is continuing his research into trubulence and trasport in superfluid dilute quantum gasses. His major academic acheivements include demonstrating the utility of Digital-Micromirror Devices in quantum dilute gasses. The first experimental realization of negative absolute temperature Onsager vortices, and demonstrating the equivalence between superfluid transport near equilibrium and acoustic transport in classical systems.