Fisher, Shaun N. and Guénault, A.M. and Hale, A. J. and Pickett, George R. (2000) Andreev reflection of quasiparticles by a vortex tangle in superfluid He-3-B? Journal of Low Temperature Physics, 121 (5-6). pp. 393-398. ISSN 0022-2291
Full text not available from this repository.Abstract
We have made the surprising discovery that the thermal damping of a vibrating wire resonator in superfluid He-3-B at ultra low temperatures is considerably depressed when a second wire in the vicinity is driven supercritically. The damping of a vibrating wire resonator at low velocities in the B-phase arises from the scattering of quasiparticle excitations and has a temperature dependence proportional to the Boltzmann factor exp(-Delta /kT) at low temperatures. At higher velocities (v > v(L)/3), the wire breaks Cooper pairs and emits a quasiparticle beam. At first sight it seems paradoxical that heating the superfluid can reduce the quasiparticle flux: on a neighbouring wire. We can only understand this on the basis that vorticity emitted by the supercritical wire shields, via Andreev reflection, part of the background quasiparticle flux: from reaching the other wire. If this interpretation, is correct, these techniques will provide a sensitive probe of vortex dynamics in the ultra low temperature regime.