Boundary phenomena in a helium II+ solid system

Journal Article · Wed Dec 01 04:00:00 EST 1982 · Sov. Phys. - JETP (Engl. Transl.); (United States)

OSTI ID:5810595

Bondarev, V N

A quasiclassical approximation is constructed of the quantum analog of the dispersion equation for a roton. With the concept of a two-dimensional roton (an elementary excitation localized in helium at the interface with a solid substrate) as the basis, the contribution of rotons to the surface normal component ..nu.. is considered. It is shown that at T>1 K the increment to ..nu.., due to the quasiclassical branches of two-dimensional rotons, is comparable with the contribution of the main branch. Allowance for this increment makes it possible to reconcile the results of neutron experiments with measurements of the density of the superfluid component in He II films. In addition, a dispersion law is obtained for a surface wave of the phonon type propagating along the interface between the He II and the substrate. The possibility of decay of a surface phonon is investigated and the phonon damping coefficient at T = 0 is found. It is proposed that the branches of the two-dimensional rotons are direct continuations of the phonon section of the surface-excitation spectrum, a hypothesis whose experimental investigation would be of interest.

• Research Organization: Physics Research Institute, Odessa State University
• OSTI ID: 5810595
• Journal Information: Sov. Phys. - JETP (Engl. Transl.); (United States), Journal Name: Sov. Phys. - JETP (Engl. Transl.); (United States) Vol. 56:6; ISSN SPHJA
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DISPERSION RELATIONS
EVEN-EVEN NUCLEI
FLUIDS
HELIUM 4
HELIUM II
HELIUM ISOTOPES
INTERFACES
ISOTOPES
LIGHT NUCLEI
NUCLEI
PHONONS
QUANTUM FLUIDS
QUASI PARTICLES
ROTONS
SEMICLASSICAL APPROXIMATION
STABLE ISOTOPES
SUBSTRATES
SURFACE PROPERTIES
TWO-DIMENSIONAL CALCULATIONS