Data di Pubblicazione:
2018
Citazione:
Probing quantum turbulence in 4He by quantum evaporation measurements / I. Amelio, D.E. Galli, L. Reatto. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 121(2018 Jul 05), pp. 015302.015302-1-015302.015302-5. [10.1103/PhysRevLett.121.015302]
Abstract:
Theory of superfluid 4He shows that, due to strong correlations and backflow effects, the density profile
of a vortex line has the character of a density modulation and it is not a simple rarefaction region as found in
clouds of cold bosonic atoms.We find that the basic features of this density modulation are represented by a
wave packet of cylindrical symmetry in which rotons with a positive group velocity have a dominant role:
The vortex density modulation can be viewed as a cloud of virtual excitations, mainly rotons, sustained
by the phase of the vortex wave function. This suggests that in a vortex reconnection some of these
rotons become real so that a vortex tangle is predicted to be a source of nonthermal rotons. The presence
of such vorticity induced rotons can be verified by measurements at low temperature of quantum
evaporation of 4He atoms. We estimate the rate of evaporation and this turns out to be detectable by current
instrumentation. Additional information on the microscopic processes in the decay of quantum turbulence
will be obtained if quantum evaporation by high energy phonons should be detected.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
I. Amelio, D.E. Galli, L. Reatto
Link alla scheda completa: