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arXiv · 0806.0908

High frequency sound in superfluid 3He-B

J. P. Davis·H. Choi·J. Pollanen·W. P. Halperin
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Abstract

We present measurements of the absolute phase velocity of transverse and longitudinal sound in superfluid 3He-B at low temperature, extending from the imaginary squashing mode to near pair-breaking. Changes in the transverse phase velocity near pair-breaking have been explained in terms of an order parameter collective mode that arises from f-wave pairing interactions, the so-called J=4- mode. Using these measurements, we establish lower bounds on the energy gap in the B-phase. Measurement of attenuation of longitudinal sound at low temperature and energies far above the pair-breaking threshold, are in agreement with the lower bounds set on pair-breaking. Finally, we discuss our estimations for the strength of the f-wave pairing interactions and the Fermi liquid parameter, F4s.

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J. P. Davis, H. Choi, J. Pollanen, W. P. Halperin. 2008-07-24. High frequency sound in superfluid 3He-B. https://doi.org/10.1007/s10909-008-9819-1

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