Mixed Bose - Fermi Superfluids and Fermi Liquid Transport in the Presence of Disorder

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Parpia9970817This low temperature physics research project seeks to create conditions under which He-3, a Fermi superfluid and He-4, a Bose superfluid coexist, interpenetrate and interact with each other. Such a coexistence and interpenetration of two distinct superfluid species does not occur in the bulk. The properties of Aerogel, a dilute space-filling glass impurity allow this new state of matter to be examined. In addition the project proposes to initiate the measurement of flow of normal 3He in aerogel. When the aerogel is sufficiently dense, the 3He should display characteristics similar to those observed in quantum transport in electron systems, while in the dilute limit, the flow should display a crossover from the Drude to Poiseuille flow behavior. These phenomena are important both from the fundamental physics viewpoint as well for potential applications. Flow generation and measurement techniques as well as the knowledge gained from the measurements will have applications in many fields. Graduate students receive training appropriate to careers in academia, industrial R & D, and the financial sector. Their familiarity with technical areas, ability to innovate, and to integrate new technology is highly sought after. %%%This low temperature research project concentrates on the effects of a very dilute glass (aerogel) on 3He. The aerogel introduces disorder into the 3He and allows another superfluid, 4He, to penetrate inside the core of the 3He superfluid. The project will look for coexistent superfluids and for interactions between the two distinct 4He and 3He superfluids. The esearcher will also examine in detail the effect of disorder on the flow of a quantum fluid. Why is this work at such an extreme low temperature important for the Nation? Quantum mechanical interference in electronic superconductors can be used to image weak magnetic fields, for example from activity in the brain. Quantum mechanical interference between two different species of superfluids has never been studied and could lead to new applications. The techniques needed to induce and measure flow in the quantum and conventional regimes as well as the understanding gained will have applications for flow in porous media. Areas such as oil field recovery, the management of aquifers, as well as the flow of biological fluids could benefit. Graduate students receive training appropriate to careers in academia, industrial R & D, and the financial sector. Their familiarity with technical areas, ability to innovate and manage a project from start to finish, as well as to integrate new technology is highly sought after.***