Please use this identifier to cite or link to this item:
Title: Critical Landau Velocity in Helium Nanodroplets
Author: Brauer, Nils B.
Smolarek, Szymon
Loginov, Evgeniy
Mateo Valderrama, David
Hernando, Alberto
Pi Pericay, Martí
Barranco Gómez, Manuel
Buma, Wybren J.
Drabbels, Marcel
Keywords: Física de partícules
Particle physics
Issue Date: 8-Oct-2013
Publisher: American Physical Society
Abstract: The best-known property of superfluid helium is the vanishing viscosity that objects experience while moving through the liquid with speeds below the so-called critical Landau velocity. This critical velocity is generally considered a macroscopic property as it is related to the collective excitations of the helium atoms in the liquid. In the present work we determine to what extent this concept can still be applied to nanometer-scale, finite size helium systems. To this end, atoms and molecules embedded in helium nanodroplets of various sizes are accelerated out of the droplets by means of optical excitation, and the speed distributions of the ejected particles are determined. The measurements reveal the existence of a critical velocity in these systems, even for nanodroplets consisting of only a thousand helium atoms. Accompanying theoretical simulations based on a time-dependent density functional description of the helium confirm and further elucidate this experimental finding.
Note: Reproducció del document publicat a:
It is part of: Physical Review Letters, 2013, vol. 111, num. 15, p. 153002
Related resource:
ISSN: 0031-9007
Appears in Collections:Articles publicats en revistes (Física Quàntica i Astrofísica)

Files in This Item:
File Description SizeFormat 
632249.pdf770.98 kBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.