Topological Surface States and New Phases in Superfluid 3He

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Technical AbstractThis individual investigator project trains graduate and undergraduate students who conduct research on the structure of various quantum condensed phases with a focus on 3He superfluids at low temperatures. The central part of this proposal is to characterize certain types of quantum states which have topological significance and can be found at the surface of these superfluids. The impact of the research will be felt over a broad range of condensed matter physics, on field theories basic to the understanding of neutrinos, and may have relevance to the understanding of dark matter. New superfluid phases of helium have been predicted to exist within globally-anisotropic, highly-porous, silica aerogels. These materials will be grown with assistance from undergraduate students who characterize them using optical birefringence, and small angle Xray techniques. Additionally, our aerogels will be provided to a half-dozen laboratories around the world where there have been specific requests. High-resolution acoustics in resonant cavities will be used used to investigate surface quantum states in thin samples of superfluid 3He and a search for direct evidence of broken, time-reversal symmetry will be conducted. This fundamental broken symmetry is of importance to studies on various unconventional superconducting materials conducted in other laboratories.Non-Technical AbstractThis individual investigator project supports graduate and undergraduate education through their research in experimental physics. The project develops, creates, and characterizes new quantum states of matter which exhibit symmetry properties that have the potential for impact on our society, including high speed computation, transfer of mass in the form of frictionless superfluids, as well as applications of superconductivity. Highly porous, gel structures, so-called aerogels, will be grown and characterized in order to control the quantum states of helium superfluids imbibed within. These highly homogeneous samples will also be provided to a half dozen other laboratories that have requested them. The basic scientific research conducted in this project provides student training in high-resolution acoustics, nuclear magnetic resonance, and low temperature techniques and promotes awareness in both public and scientific communities to conserve helium as a valuable natural resource.