Anomalous damping of a low frequency vibrating wire in superfluid He-3-B due to vortex shielding

Bradley, D. I. and Fear, M. J. and Fisher, Shaun and Guenault, A. M. and Haley, R. P. and Lawson, C. R. and Pickett, G. R. and Schanen, R. and Tsepelin, V. (2014) Anomalous damping of a low frequency vibrating wire in superfluid He-3-B due to vortex shielding. Journal of Low Temperature Physics, 175 (1-2). pp. 372-378. ISSN 0022-2291

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Abstract

We have investigated the behaviour of a large vibrating wire resonator in the B-phase of superfluid He-3 at zero pressure and at temperatures below 200 mu K. The vibrating wire has a low resonant frequency of around 60 Hz. At low velocities the motion of the wire is impeded by its intrinsic (vacuum) damping and by the scattering of thermal quasiparticle excitations. At higher velocities we would normally expect the motion to be further damped by the creation of quasiparticles from pair-breaking. However, for a range of temperatures, as we increase the driving force we observe a sudden decrease in the damping of the wire. This results from a reduction in the thermal damping arising from the presence of quantum vortex lines generated by the wire. These vortex lines Andreev-reflect low energy excitations and thus partially shield the wire from incident thermal quasiparticles.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Low Temperature Physics
Additional Information:
© The Author(s) 2013. This article is published with open access at Springerlink.com
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100/3104
Subjects:
ID Code:
70111
Deposited By:
Deposited On:
25 Jul 2014 08:55
Refereed?:
Yes
Published?:
Published
Last Modified:
28 May 2020 03:16