Vortex core size in submonolayer superfluid {sup 4}He films

Journal Article · Wed Nov 01 04:00:00 EST 1995 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1007/BF00753338· OSTI ID:183407

Cho, H; Williams, G A ^[1]

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1. Univ. of California, Los Angeles, CA (United States)

The superfluid transition of {sup 4}He films adsorbed on 500{angstrom} diameter slip-cast alumina powder is measured with a torsion oscillator technique for films with transition temperatures between 50 and 700 mK. The transitions are found to be controlled by the universal Kosterlitz-Thouless critical line, but a strong increase in the broadening of the transition is observed for the thinnest films. Analysis in terms of vortex pair excitations shows that this broadening results from a vortex core size that increases rapidly as the film is thinned, scaling roughly with the interparticle spacing of the superfluid submonolayer. Third sound modes are identified in the dissipation, in addition to a broad peak from the vortex unbinding. This system provides evidence of a three-dimensional superfluid transition mediated by vortex excitations.

• Sponsoring Organization: USDOE
• OSTI ID: 183407
• Report Number(s): CONF-950676--; CNN: Grant DMR 91-20170; Grant 95-00653; Grant 25104-AC5,2
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 3-4 Vol. 101; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
ALUMINIUM OXIDES
HELIUM 4
SUPERFLUIDITY
TEMPERATURE DEPENDENCE
TRANSITION TEMPERATURE
VORTICES