While there has been considerable theoretical attention given to nonlinear (soliton) effects for adsorbed films of superfluid 4He, there have been no systematic experimental studies. In this paper we report measurements of wave propagation in such films with drive levels varying over five orders of
Solitons in superfluid4He films
โ Scribed by Sadao Nakajimia; Susumu Kurihara; Kiyoshi Tohdoh
- Publisher
- Springer US
- Year
- 1980
- Tongue
- English
- Weight
- 432 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0022-2291
No coin nor oath required. For personal study only.
โฆ Synopsis
The Korteweg-de Vries (KdV) equation is derived from Landau two-fluid hydrodynamics applied to the thickness oscillation of the superfluid 4He film at low temperatures, where the main restoring force is van der Waals attraction from the substrate and the thermomechanical force due to phonons is a small correction. Since the usual third-sound generators and detectors are far wider than the individual solitons, the asymptotic solution of the KdV equation provided by the inverse scattering method is coarse-grained by regarding it as a continuous train of sha,? pulses. The envelope so obtained still shows a singular front proportional to (t-to)71/2, where to is the arrival time of the fastest soliton, and should therefore be observable with the appropriate experimental arrangement.
๐ SIMILAR VOLUMES