Quantum Turbulence in Superfluid D~3He Illuminated by a Beam of Quasiparticle Excitations

摘要

We have measured directly the Andreev scattering of a controllable beam of quasiparticle excitations by a localized tangle of quantum vortices in superfluid ~3He-B at low temperatures. We present a microscopic description of the Andreev scattering from a vortex line allowing us to estimate the vortex separation scale in a dilute tangle of vortices, providing a better comparison of the observed decay lime of the turbulence with recent numerical simulations. The experiments also suggest that below 200 μK we reach the low temperature limit for turbulent dynamics.