Why phonon scattering in glasses is universally small at low temperatures
ORAL
Abstract
We present a novel view of the standard model of tunneling two level systems (TLS) to explain the puzzling universal value of a quantity, C ~ 3 x 10-4, that characterizes phonon scattering in glasses below 1 K as reflected in thermal conductivity, ultrasonic attenuation, internal friction, and the change in sound velocity. Physical considerations lead to a broad distribution of phonon-TLS couplings that (1) exponentially renormalize tunneling matrix elements, and (2) reduce the TLS density of states through TLS-TLS interactions. We find good agreement between theory and experiment for a variety of individual glasses.
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Presenters
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Clare Yu
Department of Physics and Astronomy, University of California, Irvine, University of California, Irvine
Authors
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Herve M. Carruzzo
Department of Physics and Astronomy, University of California, Irvine, University of California, Irvine
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Clare Yu
Department of Physics and Astronomy, University of California, Irvine, University of California, Irvine